Electrospun PCL/PGS composite fibers incorporating bioactive glass particles for soft tissue engineering applications - Luginina, Marina; Schuhladen, Katharina; Orrú, Roberto; Cao, Giacomo; Boccaccini, Aldo R.; Liverani, Liliana (Nanomaterials, 2020)
Poly(glycerol-sebacate) (PGS) and poly(epsilon caprolactone) (PCL) have been widely investigated for biomedical applications in combination with the electrospinning process. Among others, one advantage of this blend is its suitability to be processed with benign solvents for electrospinning. In this work, the suitability of PGS/PCL polymers for the fabrication of composite fibers incorporating bioactive glass (BG) particles was investigated. Composite electrospun fibers containing silicate or borosilicate glass particles (13-93 and 13-93BS, respectively) were obtained and characterized. Neat PCL and PCL composite electrospun fibers were used as control to investigate the possible effect of the presence of PGS and the influence of the bioactive glass particles. In fact, with the addition of PGS an increase in the average fiber diameter was observed, while in all the composite fibers, the presence of BG particles induced an increase in the fiber diameter distribution, without changing significantly the average fiber diameter. Results confirmed that the blended fibers are hydrophilic, while the addition of BG particles does not affect fiber wettability. Degradation test and acellular bioactivity test highlight the release of the BG particles from all composite fibers, relevant for all applications related to therapeutic ion release, i.e., wound healing. Because of weak interface between the incorporated BG particles and the polymeric fibers, mechanical properties were not improved in the composite fibers. Promising results were obtained from preliminary biological tests for potential use of the developed mats for soft tissue engineering applications.
CRIS-Team Scopus Importer:2020-06-23
Keywords: Benign solvents; Bioactive glass; Composite fibers; Electrospinning; Poly(glycerol-sebacate)

Electrospun PHB/PCL/FUMED Silica Fibrous Structure for Bone Tissue Engineering - Ding, Yaping; Li, Wei; Roether, Judith; Boccaccini, Aldo R.; Schubert, Dirk W. (Polychar 23rd, 2015)

Electrospun Polyhydroxybutyrate/Poly(ϵ-caprolactone)/58S Sol-Gel Bioactive Glass Hybrid Scaffolds with Highly Improved Osteogenic Potential for Bone Tissue Engineering - Ding, Yaping; Li, Wei; Mueller, Teresa; Schubert, Dirk W.; Boccaccini, Aldo R.; Yao, Qingqing; Roether, Judith (ACS Applied Materials and Interfaces, 2016)
Electrospinning of biopolymer and inorganic substances is one of the efficient ways to combine various advantageous properties in one single fibrous structure with potential for tissue engineering applications. In the present study, to integrate the high stiffness of polyhydroxybutyrate (PHB), the flexibility of poly(ε-caprolactone) (PCL) and the bioactivity of 58S bioactive glass, PHB/PCL/58S sol-gel bioactive glass hybrid scaffolds were fabricated using combined electrospinning and sol-gel method. Physical features such as fiber diameter distribution, mechanical strength and Young's modulus were characterized thoroughly. FTIR analysis demonstrated the successful incorporation of 58S bioactive glass into the blend polymers, which greatly improved the hydrophilicity of PHB/PCL fibermats. The primary biological response of MG-63 osteoblast-like cells on the prepared fibrous scaffolds was evaluated, proving that the 58S glass sol containing hybrid scaffold were not only favorable to MG-63 cell adhesion but also slightly enhanced cell viability and significantly increased alkaline phosphate activity
Keywords: sol-gel method; tissue engineering; poly(ϵ-caprolactone); polyhydroxybutyrate; hybrid scaffolds; electrospinning

Electrospun Polyhydroxybutyrate/Poly(ϵ-caprolactone)/58S Sol-Gel Bioactive Glass Hybrid Scaffolds with Highly Improved Osteogenic Potential for Bone Tissue Engineering - Ding, Yaping; Li, Wei; Mueller, Teresa; Schubert, Dirk W.; Boccaccini, Aldo R.; Yao, Qingqing; Roether, Judith (ACS Applied Materials and Interfaces, 2016)
Keywords: electrospinning; hybrid scaffolds; poly(ϵ-caprolactone); polyhydroxybutyrate; sol-gel method; tissue engineering

Electrospun Polyhydroxybutyrate/Poly(ε-caprolactone)/Sol-Gel-Derived Silica Hybrid Scaffolds with Drug Releasing Function for Bone Tissue Engineering Applications. - Ding, Yaping; Li, Wei; Correia, Alexandra; Yang, Yuyun; Zheng, Kai; Liu, Dongfei; Schubert, Dirk W.; Boccaccini, Aldo R.; Santos, Helder A.; Roether, Judith (ACS Applied Materials and Interfaces, 2018)
Electrospun hybrid scaffolds are an effective platform to deliver drugs site specifically for the prevention and treatment of diseases in addition to promote tissue regeneration because of the flexibility to load drugs therein. In the present study, electrospun hybrid scaffolds containing antibiotics were developed to support cellular activities and eliminate potential postoperative inflammation and infection. As a model drug, levofloxacin (LFX) was successfully incorporated into pure polyhydroxybutyrate/poly(ε-caprolactone) (PHB/PCL) scaffolds and PHB/PCL/sol-gel-derived silica (SGS) scaffolds. The influence of LFX on the morphology, mechanical performance, chemical structure, drug release profile, and antibacterial effect of the scaffolds was thoroughly and comparatively investigated. MG-63 osteoblast-like cell cultivation on both scaffolds certified that LFX inclusion did not impair the biocompatibility. In addition to the favorable cellular proliferation and differentiation, scaffolds containing both LFX and SGS displayed highly increased mineralization content. Therefore, the present multifunctional hybrid scaffolds are promising in tissue engineering applications.

Electrospun Polyhydroxybutyrate/Poly(ϵ-caprolactone)/Sol-Gel-Derived Silica Hybrid Scaffolds with Drug Releasing Function for Bone Tissue Engineering Applications - Ding, Yaping; Li, Wei; Correia, Alexandra; Yang, Yuyun; Zheng, Kai; Liu, Dongfei; Schubert, Dirk W.; Boccaccini, Aldo R.; Santos, Helder A.; Roether, Judith (ACS Applied Materials and Interfaces, 2018)
Electrospun hybrid scaffolds are an effective platform to deliver drugs site specifically for the prevention and treatment of diseases in addition to promote tissue regeneration because of the flexibility to load drugs therein. In the present study, electrospun hybrid scaffolds containing antibiotics were developed to support cellular activities and eliminate potential postoperative inflammation and infection. As a model drug, levofloxacin (LFX) was successfully incorporated into pure polyhydroxybutyrate/poly(ε-caprolactone) (PHB/PCL) scaffolds and PHB/PCL/sol-gel-derived silica (SGS) scaffolds. The influence of LFX on the morphology, mechanical performance, chemical structure, drug release profile, and antibacterial effect of the scaffolds was thoroughly and comparatively investigated. MG-63 osteoblast-like cell cultivation on both scaffolds certified that LFX inclusion did not impair the biocompatibility. In addition to the favorable cellular proliferation and differentiation, scaffolds containing both LFX and SGS displayed highly increased mineralization content. Therefore, the present multifunctional hybrid scaffolds are promising in tissue engineering application
Keywords: hybrid scaffolds; poly(ϵ-caprolactone); antibacterial; polyhydroxybutyrate; sol.gel silica

Electrospun poly(ε-caprolactone)/poly(glycerol sebacate) aligned fibers fabricated with benign solvents for tendon tissue engineering - Iorio, Francesco; El Khatib, Mohammad; Wöltinger, Natalie; Turriani, Maura; Di Giacinto, Oriana; Mauro, Annunziata; Russo, Valentina; Barboni, Barbara; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2024)
The electrospinning technique is a commonly employed approach to fabricate fibers intended for various tissue engineering applications. The aim of this study is to develop a novel strategy for tendon repair through the use of aligned poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) fibers fabricated in benign solvents, and further explore the potential application of PGS in tendon tissue engineering (TTE). The fibers were characterized for their morphological and physicochemical properties; amniotic epithelial stem cells (AECs) were used to assess the fibers teno-inductive and immunomodulatory potential due to their ability to teno-differentiate undergoing first a stepwise epithelial to mesenchymal transition, and due to their documented therapeutic role in tendon regeneration. The addition of PGS to PCL improved the spinnability of the polymer solution, as well as the uniformity and directionality of the so-obtained fibers. The mechanical properties were in the range of most TTE applications, specifically in the case of PCL/PGS 4:1 and 2:1 ratios. Compared to PCL alone, the same ratios also allowed a better AECs infiltration and growth over 7 days of culture, and triggered the activation of tendon-related genes (SCX, COL1, TNMD) and the expression of tenomodulin (TNMD) at the protein level. Concerning the immunomodulatory properties, both PCL and PCL/PGS fibers negatively affected the immunomodulatory profile of AECs, up-regulating both anti-inflammatory (IL-10) and pro-inflammatory (IL-12) cytokines over 7 days of culture. Overall, PCL/PGS 2:1 fibers fabricated with benign solvents proved to be the most suitable composition for TTE application based on their topographical cues, mechanical properties, biocompatibility, and teno-inductive properties.
CRIS-Team Scopus Importer:2024-09-27
Keywords: amniotic epithelial stem cells; electrospinning; poly(glycerol sebacate); poly(ε-caprolactone); scaffolds; tendon tissue engineering

Electrospun porous phosphate-based glass fibres containing gallium and clove oil: Cytotoxicity and antioxidant properties - Moghaddam, Zarrin; Nery, Eveliny Tomas; Ünalan, Irem; Hoxha, Agron; Felipe-Sotelo, Monica; Zhao, Hongjuan; Pinna, Alessandra; Abrahams, Isaac; Smales, Glen J.; Boccaccini, Aldo R.; Carta, Daniela (Ceramics International, 2025)
In this work, a novel route for the synthesis of porous phosphate-based glass fibres (PGFs) in the system P2O5-CaO-Na2O-xGa2O3 (x = 0, 0.2, 0.5 and 1 mol %) via electrospinning (ES) of polyphosphate gels is presented. Polyphosphate gels, prepared via the sustainable, fast and cost-effective technique of coacervation, are combined with the surfactant Pluronic 123 (P123) as a porogen, which represents the novelty of this work as no previous porous PGFs have been manufactured via this method. Porosity in PGFs is generated by removal of P123 via calcination. Scanning electron microscopy (SEM) demonstrates the presence of pores in the 100 nm-2 μm range, often aligned along the direction of the fibres. The structure of all PGFs was investigated using the complementary techniques of X-ray diffraction (XRD), and Raman and Fourier Transform Infrared (FT-IR) spectroscopies. Energy Dispersive X-ray Spectroscopy (EDX) was used to assess the elemental composition of PGFs. Release of species following 3, 24, 48 and 72 h of immersion in deionised water (DI) was investigated via microwave plasma atomic emission spectroscopy (MP-AES). Dissolution products after 24 h of immersion of all PGFs in water (DI) were tested for antibacterial activity against the bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Results show that all PGFs are active against E. coli, whereas only PGFs containing the highest gallium content are active against S. aureus. MTT and MTS assays, colorimetric assays routinely used for measuring cellular growth and metabolic activity, demonstrate that 24 h dissolution products are non-cytotoxic when in contact with keratinocyte cells (HaCaTs). PGFs show high encapsulation efficiency (∼99.99 %) of the natural antioxidant clove oil (3 w/v%). Antioxidant activity (DPPH) and total phenolic content (TPC) assays performed on clove oil loaded PGFs show that antioxidant properties increase with the gallium content. This work demonstrates the feasibility of manufacturing porous PGFs with antioxidant and antibacterial properties for wound healing applications using the sustainable and cost-effective method of coacervation.
CRIS-Team Scopus Importer:2025-04-01
Keywords: Clove oil; Electrospinning; Gallium; Pluronic 123; Porous phosphate-based glass fibre

ELECTROSPUN SCAFFOLDS FOR OVARIAN TISSUE ENGINEERING: KEY POINTS OF SCAFFOLD-FOLLICLES INTERACTIONS - Liverani, Liliana; Bleisinger, Nathalie; Hoffmann, Inge; Beckmann, Matthias; Dittrich, Ralf; Boccaccini, Aldo R. (TISSUE ENGINEERING PART A, 2022)
CRIS-Team WoS Importer:2022-08-12

Electrospun Zein Fibers Incorporating Poly(glycerol sebacate) for Soft Tissue Engineering. - Vogt, Lena; Liverani, Liliana; Roether, Judith; Boccaccini, Aldo R. (Nanomaterials, 2018)
For biomedical applications such as soft tissue engineering, plant proteins are becoming increasingly attractive. Zein, a class of prolamine proteins found in corn, offers excellent properties for application in the human body, but has inferior mechanical properties and lacks aqueous stability. In this study, electrospun scaffolds from neat zein and zein blended with prepolymer and mildly cross-linked poly(glycerol sebacate) (PGS) were fabricated. Less toxic solvents like acetic acid and ethanol were used. The morphological, physiochemical and degradation properties of the as-spun fiber mats were determined. Neat zein and zein-PGS fiber mats with high zein concentration (24 wt % and 27 wt %) showed defect-free microstructures. The average fiber diameter decreased with increasing PGS amount from 0.7 ± 0.2 µm to 0.09 ± 0.03 µm. The addition of PGS to zein resulted in a seven-fold increase in ultimate tensile strength and a four-fold increase in failure strain, whereas the Young’s Modulus did not change significantly. Degradation tests in phosphate buffered saline revealed the morphological instability of zein containing fiber mats in contact with aqueous media. Therefore, the fibers were in situ cross-linked with N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide (EDC)/N-Hydroxysuccinimide (NHS), which led to improved morphological stability in aqueous environment. The novel fibers have suitable properties for application in soft tissue engineering.
Keywords: zein; poly(glycerol sebacate); electrospinning; nano-fibers; soft tissue engineering

Elektrophoretische Abscheidung von multifunktionalen Kompositschichten aus Polymer und bioaktivem Glas - Seuß, Sigrid (2016)
As the anticipated average life of the population continues to increase, the need for improved implant materials grows. There is a whole variety of implants available for various parts of the body, for example bone and joint replacement, parts of internal organs or artificial blood vessels. Research in this field has become increasingly important to ensure the quality of life of patients after implantation. For joint replacement implants, the most important aspect is a perfect fixation of the implant to the surrounding tissue to prevent loosening. A loosened implant can lead to infections and pain and has to be removed in many cases, decreasing the quality of life of patients. Bioactive materials like hydroxyapatite or bioactive glass are useful materials to promote strong bonding of implant to bone. These materials form a hydroxycarbonate apatite layer in contact with the surrounding body fluid and enhance osteoblast activity. Thus bioactive materials are used as coatings on metallic implants for enhancing the bone-implant interface. It is also well known that ceramic materials as well as the commonly used metallic implants made from stainless steel or titanium alloys exhibit problems concerning their mechanical properties. Especially the high Young’s modulus in comparison to bone is disadvantageous as it can lead to stress shielding, which can cause decomposition of the surrounding bone. To avoid stress shielding, a coating with a lower Young’s modulus can be of advantage. Polymer materials are good candidates for this purpose as they can also be used as a matrix material for incorporating bioactive ceramic particles. One possible coating process for this purpose is electrophoretic deposition (EPD), which gives the chance to deposit several materials in one single step from a suspension that contains the different particles and molecules. By using EPD, the coating thickness and composition can be tailored by adjusting the processing parameters and suspension composition. In this project two ways of parameter optimization were used: trial-and-error, which is a rather time consuming method and the Taguchi method, which is a statistical way to find the most robust system with the least variation. Trial-and-error was used for the more complex composite systems, whereas the successful use of statistical evaluation was shown for the single material systems, namely PEEK and chitosan. The use of coatings as part of implant materials induces several requirements. Coatings were examined applying a wide range of characterization methods. The use of contact angle measurements gives initial information about hydrophilicity of the surface and hence about cell attachment, as very high and low contact angles are unfavorable. This is also the case for the roughness of the produced coatings. Therefore laserprofilometry was chosen to assess the roughness. Another important factor is the evaluation of the attachment of the coatings to the substrate material, which was stainless steel in this project. A problem that can occur at implant site is a bacterial infection that also can lead to a failure of the implant resulting in a second surgery to remove the implant. There are two main ways to overcome this problem, either by using drugs (antibiotics) or the use of antibacterial agents (ions) such as silver. Drugs can be released directly at the implant site by using a degradable polymer matrix that releases the drug over a longer time period. In this project the naturally derived polymer chitosan was selected as a matrix for bioactive glass particles and the antibiotic tetracycline. Coatings of this material combination were developed and characterized. It was shown that tetracycline can be released over several weeks with a burst in the beginning to prevent early infections directly after the surgery when the immune system of the patient is weakened. Bacterial studies using E. coli cells confirmed the successful antibacterial effect of these coatings that can be adjusted by changing the antibiotic concentration in suspension. In addition, studies in simulated body fluid (SBF) showed the bioactive properties of the coatings by the formation of hydroxyapatite on the surface after immersion for 21 days in SBF. Different bioactive glass particle sizes were used ranging from nanometer to micrometer size and it was depicted that the optimum properties in terms of bioactivity, cell attachment and spreading can be achieved using nano-sized bioactive glass particles. Prior to cell culture studies the behavior of the coatings applying different sterilization methods such as sterilization in the furnace, in the autoclave and under UV light was investigated in terms of coating attachment and possible chemical changes of the coatings. The second approach to achieve antibacterial properties involved the use of silver nanoparticles. In this case a non-degradable polymer matrix was used. Polyetheretherketone (PEEK) was chosen for this purpose as it exhibits excellent mechanical properties and is well processible due to its excellent chemical and thermal stability. A heat treatment step in a furnace was required to densify the coatings, which was optimized at different temperatures and the influence of the heat treatment process on materials properties such as crystallinity was investigated. PEEK was taken as a matrix material for bioactive glass and silver nanoparticles and the successful composite coating formation by EPD was demonstrated. This material combination was also seen to lead to a sufficient apatite formation in SBF. Bacteria studies using E. coli indicated that the antibacterial properties can be tailored by changing the silver concentration in suspension. However, it is important that not only an antibacterial effect occurs, but still the biocompatibility in terms of cell attachment and cell spreading is maintained. This was successfully tested using MG 63 osteoblast-like cells. Also in this case the sterilization behavior of the coatings was investigated to find the most suitable sterilization process that avoids degradation or damage of the coating,As a last step for the two material systems, the coating formation on three-dimensional substrates was evaluated. For the PEEK system, a dental screw was used, whereas for chitosan, a porous titanium alloy TiAl6V4 scaffold was applied. For both systems the successful coating formation using EPD could be shown, which reveals that EPD is a suitable method for the deposition of multifunctional biomedical coatings on 3D structures. The properties and thicknesses of the coatings can be readily adjusted by changing the coating process. Thus, the results of this investigation have expanded the applicability of EPD to a family of both biodegradable and permanent coatings which exhibit combined bioactivity and antibacterial behavior.; In den letzten Jahren ist die Lebenserwartung der Menschheit stetig angestiegen, was dazu führt, dass die Anforderungen an Implantatmaterialien wachsen. Es gibt eine große Anzahl an Implantaten, von Knochen- und Gelenkersatz, bis hin zu Teilen von Organen und künstlichen Blutgefäßen. Durch die wachsende Nachfrage wird die Forschung in diesem Bereich immer wichtiger, um die Lebensqualität nach dem Eingriff zu erhalten. Bei einem Gelenkersatz ist es besonders wichtig eine ausreichende Anbindung des Implantats an das umliegende Gewebe zu erreichen, um eine Lockerung des Implantats zu verhindern. Eine Lockerung würde die Lebensqualität vermindern, da sie zu Infektionen und Schmerzen führen kann. Im schlimmsten Fall ist es nötig das Implantat zu entfernen. Um eine bessere Anbindung zu erzielen, werden bioaktive Materialien wie Hydroxylapatit oder bioaktives Glas verwendet. Diese Materialien begünstigen eine starke Bindung zwischen Implantat und Knochen. Bioaktive Materialien bilden eine Hydroxylcarbonat Apatit Schicht, wenn sie in Kontakt mit Körperflüssigkeiten kommen. Zusätzlich wird die Osteoblasten Aktivität erhöht. Aus diesem Grund werden Beschichtungen aus bioaktiven Materialien auf metallischen Implantaten verwendet, um die Grenzfläche zwischen Knochen und Implantat zu verstärken. Allerdings treten bei der Verwendung von keramischen Materialien, genauso wie bei den normalerweise verwendeten metallischen Implantatmaterialien aus Edelstahl oder Titanlegierungen Probleme auf. Diese sind bedingt durch die mechanischen Eigenschaften, besonders auf Grund des hohen E-Moduls. Dieser ist im Vergleich zu Knochen sehr hoch, was zu „stress shielding“ führen kann und damit einen Abbau des Knochengewebes zur Folge hat. Stress Shielding kann vermieden werden, wenn die Implantatmaterialien mit einem Material beschichtet werden, das einen niedrigeren E-Modul aufweist. Es hat sich gezeigt, dass sich Polymere für diesen Zweck gut eignen, da sie auch als Matrix für keramische Partikel verwendet werden können. Ein möglicher Beschichtungsprozess ist die elektrophoretische Abscheidung (EPD). Bei diesem Prozess können verschiedene Materialien, die in Pulverform vorliegen in einem Schritt aus einer Suspension direkt auf das Substrat abgeschieden werden. Die Dicke und Zusammensetzung der Schicht können mit Hilfe von EPD einfach eingestellt werden, indem man die Prozessparameter und Zusammensetzung der Suspension verändert. In dieser Arbeit wurden zwei verschiedene Methoden verwendet, um die Prozessparameter zu optimieren: die zeitaufwändigere „Trial-and-Error-Methode“ und die Taguchi Methode. Die Taguchi Methode ist eine statistische Prozessoptimierung, bei der das robusteste System mit der kleinsten Schwankung gefunden wird. Trial-and-Error wurde für komplexere Kompositsysteme verwendet, während der Gebrauch der Taguchi Methode für die Einzelkomponentensysteme PEEK und Chitosan gezeigt wurde. An den Einsatz von Beschichtungen auf Implantatmaterialien werden einige Anforderungen gestellt. Aus diesem Grund wurden verschiedene Untersuchungsmethoden verwendet, um die produzierten Schichten zu analysieren. Kontaktwinkelmessungen geben Aufschluss über das Anwachsen von Zellen, da sowohl sehr hohe, wie auch sehr niedrige Kontaktwinkel nachteilig sind. Ein weiterer wichtiger Aspekt ist die Rauigkeit der hergestellten Schichten. Diese wurde mit Hilfe eines Laserprofilometers untersucht. Die Anhaftung der Schicht an das Substratmaterial, welches in diesem Fall größtenteils aus Edelstahl bestand, wurde ebenfalls untersucht.Ein weiteres Problem, das an der Stelle der Implantation auftreten kann, ist eine bakterielle Infektion, die ebenfalls zu einem Versagen des Implantats führen kann. Das hat zur Folge, dass das Implantat in einer weiteren Operation entfernt werden muss. Es gibt zwei Möglichkeiten, um Infektionen zu vermeiden, entweder durch Medikamente oder durch die Verwendung von antibakteriellen Materialien, wie zum Beispiel Silber. Im Fall von Medikamenten kann eine degradierbare Polymermatrix als Trägermaterial verwendet werden. Aus dieser wird das Medikament über einen längeren Zeitraum freigesetzt werden. In diesem Projekt wurden Beschichtungen aus dem natürlich gewonnenen Polymer Chitosan als Trägermaterial für bioaktives Glas und das Antibiotikum Tetracyclin verwendet. Freisetzungsstudien haben gezeigt, dass das Tetracyclin über einen längeren Zeitraum freigesetzt wurde. Anfangs wird eine größere Menge abgegeben, um Infektionen direkt nach der Implantation zu vermeiden, da zu diesem Zeitpunkt das Immunsystem des Patienten durch die Operation besonders geschwächt ist. Studien mit E. Coli Bakterien haben die antibakterielle Wirkung der Beschichtungen gezeigt. Außerdem war es möglich, den antibakteriellen Effekt durch die Antibiotikumkonzentration einzustellen. Versuche in simulierter Körperflüssigkeit (SBF) führten zu der Bildung von Hydroxylapatit auf der Oberfläche, womit die bioaktiven Eigenschaften der Schichten nachgewiesen wurden. Nanopartikel aus bioaktivem Glas zeigten sich im Vergleich mit unterschiedlichen Partikelgrößen im Mikro- und Nanometerbereich in Bezug auf Bioaktivität und Zellanhaftung und –ausbreitung am optimalsten. Der Einfluss von unterschiedlichen Sterilisationsmethoden wurde vor den Zellkulturstudien untersucht. Als Methoden standen Sterilisation im Ofen, im Autoklaven und unter UV Strahlung zur Auswahl. Die beste Methode wurde an Hand von bester Schichtanhaftung und kleinster Materialveränderung ausgewählt. Der zweite Ansatz, um antibakterielle Eigenschaften von Kompositschichten zu erzielen, war die Verwendung von Silbernanopartikeln. In diesem Fall wurde eine stabile Polymermatrix aus Polyetheretherketon (PEEK) verwendet. PEEK besitzt exzellente mechanische Eigenschaften und lässt sich durch eine gute chemische und thermische Beständigkeit sehr gut verarbeiten. EPD ist ein kolloidaler Prozess, wodurch eine Wärmebehandlung nach dem Beschichtungsvorgang notwendig ist, um die Schicht zu verdichten und die Anhaftung zum Substratmaterial zu verbessern. Im Fall von PEEK wurde die Wärmebehandlung in einem Ofen durchgeführt. Verschiedene Temperaturen wurden gewählt und die Schichten in Bezug auf ihre Kristallinität, Anhaftung, Kontaktwinkel und Rauigkeit untersucht. PEEK wurde in diesem Fall als Matrixmaterial für bioaktives Glas und Nanosilber verwendet. Diese Materialkombination weist eine ausreichende Apatitbildung in SBF auf, und Bakterienstudien mit E. Coli weisen auf die antibakteriellen Eigenschaften der Schichten hin. Durch die Konzentration des antibakteriellen Materials in der Schicht kann die antibakterielle Wirkung eingestellt werden. In diesem Fall wurden MG 63 osteoblastenähnliche Zellen verwendet, um die Biokompatibilität der Schichten im Hinblick auf Zellanhaftung und Zellausbreitung in vitro zu untersuchen. Vor den Zellkulturversuchen wurde der Einfluss von verschiedenen Sterilisationsmethoden betrachtet, um den bestmöglichen Prozess zu finden, der einer Beschädigung der Schicht vorbeugt.Als letztes wurde für beide Materialsysteme das Beschichtungsverhalten auf dreidimensionalen Substraten erforscht. Für die PEEK-Kompositschichten kam eine Dentalschraube zum Einsatz, während die Chitosanschichten auf einem porösen Schaum aus einer Titanlegierung aufgebracht wurden. Obwohl für beide Kombinationen die erfolgreiche Schichtbildung von multifunktionalen Schichten mit Hilfe von EPD nachgewiesen werden konnte, sind weitere Untersuchungen nötig, um den Prozess zu optimieren. Des Weiteren wurde gezeigt, dass die Eigenschaften und Schichtdicken durch Variation der Prozessparameter modifiziert werden können.
Keywords: Elektrophoretische Beschichtung; Polyetheretherketone; bioactive glass

Encapsulation of aluminium in geopolymers produced from metakaolin - Kuenzel, C.; Neville, T. P.; Omakowski, T.; Vandeperre, Luc; Boccaccini, Aldo R.; Bensted, J.; Simons, S. J. R.; Cheeseman, C. R. (Journal of Nuclear Materials, 2014)
Magnox swarf contaminated with trace levels of Al metal is an important UK legacy waste originated from the fuel rod cladding system used in Magnox nuclear power stations. Composite cements made from Portland cement and blast furnace slag form a potential encapsulation matrix. However the high pH of this system causes the Al metal to corrode causing durability issues. Geopolymers derived from metakaolin are being investigated as an alternative encapsulation matrix for Magnox swarf waste and the corrosion kinetics and surface interactions of Al with metakaolin geopolymer are reported in this paper. It is shown that the pH of the geopolymer paste can be controlled by the selection of metakaolin and the sodium silicate solution used to form the geopolymer. A decrease in pH of the activation solution reduces corrosion of the Al metal and increases the stability of bayerite and gibbsite layers formed on the Al surface. The bayerite and gibbsite act as a passivation layer which inhibits further corrosion and mitigates H generation. The research shows that optimised metakaolin geopolymers have potential to be used to encapsulate legacy Magnox swarf wastes. © 2014 Published by Elsevier B.V.

Encapsulation of Mesenchymal Stem Cells Improves Vascularization of Alginate-Based Scaffolds. - Steiner, Dominik; Lingens, Lara; Fischer, Laura; Köhn, Katrin; Detsch, Rainer; Boccaccini, Aldo R.; Fey, Tobias; Greil, Peter; Weis, Christian; Beier, Justus; Horch, Raymund E.; Arkudas, Andreas (Tissue Engineering: Parts A, B, and C, 2018)
DiI-labeled MSCs/mL ADA-GEL. Four weeks postoperatively, tissue formation and vascularization were investigated by histology and microcomputed tomography. We were able to prove vascularization originating from the AV loop in both groups with statistically significant more vessels in group B containing MSCs. Moreover, encapsulated MSCs promoted biodegradation of the ADA-GEL microcapsules. In the present study, we were able to demonstrate for the first time, the successful vascularization of ADA-GEL microcapsules by means of the AV loop. Furthermore, ADA-GEL displayed a good biocompatibility and encapsulation of MSCs into ADA-GEL microcapsule-enhanced vascularization as well as biodegradation.

Encapsulation of Rat Bone Marrow Derived Mesenchymal Stem Cells in Alginate Dialdehyde/Gelatin Microbeads with and without Nanoscaled Bioactive Glass for In Vivo Bone Tissue Engineering. - Rottensteiner-Brandl, Ulrike; Detsch, Rainer; Sarker, Bapi; Lingens, Lara; Köhn, Katrin; Kneser, Ulrich; Boßerhoff, Anja Katrin; Horch, Raymund E.; Boccaccini, Aldo R.; Arkudas, Andreas (Materials, 2018)
Alginate dialdehyde (ADA), gelatin, and nano-scaled bioactive glass (nBG) particles are being currently investigated for their potential use as three-dimensional scaffolding materials for bone tissue engineering. ADA and gelatin provide a three-dimensional scaffold with properties supporting cell adhesion and proliferation. Combined with nanocristalline BG, this composition closely mimics the mineral phase of bone. In the present study, rat bone marrow derived mesenchymal stem cells (MSCs), commonly used as an osteogenic cell source, were evaluated after encapsulation into ADA-gelatin hydrogel with and without nBG. High cell survival was found in vitro for up to 28 days with or without addition of nBG assessed by calcein staining, proving the cell-friendly encapsulation process. After subcutaneous implantation into rats, survival was assessed by DAPI/TUNEL fluorescence staining. Hematoxylin-eosin staining and immunohistochemical staining for the macrophage marker ED1 (CD68) and the endothelial cell marker lectin were used to evaluate immune reaction and vascularization. After in vivo implantation, high cell survival was found after 1 week, with a notable decrease after 4 weeks. Immune reaction was very mild, proving the biocompatibility of the material. Angiogenesis in implanted constructs was significantly improved by cell encapsulation, compared to cell-free beads, as the implanted MSCs were able to attract endothelial cells. Constructs with nBG showed higher numbers of vital MSCs and lectin positive endothelial cells, thus showing a higher degree of angiogenesis, although this difference was not significant. These results support the use of ADA/gelatin/nBG as a scaffold and of MSCs as a source of osteogenic cells for bone tissue engineering. Future studies should however improve long term cell survival and focus on differentiation potential of encapsulated cells in vivo.

Endotenon-Derived Type II Tendon Stem Cells Have Enhanced Proliferative and Tenogenic Potential - Clerici, Marta; Citro, Vera; Byrne, Amy L.; Dale, Tina P.; Boccaccini, Aldo R.; Della Porta, Giovanna; Maffulli, Nicola; Forsyth, Nicholas R. (International Journal of Molecular Sciences, 2023)
Tendon injuries caused by overuse or age-related deterioration are frequent. Incomplete knowledge of somatic tendon cell biology and their progenitors has hindered interventions for the effective repair of injured tendons. Here, we sought to compare and contrast distinct tendon-derived cell populations: type I and II tendon stem cells (TSCs) and tenocytes (TNCs). Porcine type I and II TSCs were isolated via the enzymatic digestion of distinct membranes (paratenon and endotenon, respectively), while tenocytes were isolated through an explant method. Resultant cell populations were characterized by morphology, differentiation, molecular, flow cytometry, and immunofluorescence analysis. Cells were isolated, cultured, and evaluated in two alternate oxygen concentrations (physiological (2%) and air (21%)) to determine the role of oxygen in cell biology determination within this relatively avascular tissue. The different cell populations demonstrated distinct proliferative potential, morphology, and transcript levels (both for tenogenic and stem cell markers). In contrast, all tendon-derived cell populations displayed multipotent differentiation potential and immunophenotypes (positive for CD90 and CD44). Type II TSCs emerged as the most promising tendon-derived cell population for expansion, given their enhanced proliferative potential, multipotency, and maintenance of a tenogenic profile at early and late passage. Moreover, in all cases, physoxia promoted the enhanced proliferation and maintenance of a tenogenic profile. These observations help shed light on the biological mechanisms of tendon cells, with the potential to aid in the development of novel therapeutic approaches for tendon disorders.
CRIS-Team Scopus Importer:2023-11-10
Keywords: tendinopathies; tendon regeneration; tenogenic markers; TNCs; TSCs

Engineered Nanomaterials - Misra, Superb; Tetley, Terry; Thorley, Andrew; Boccaccini, Aldo R.; Valsami-Jones, Eugenia (Pollutants, Human Health and the Environment: A Risk Based Approach, 2012)
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.engine

Engineering microstructure of hydroxyapatite by electron beam irradiation to induce controllable in vitro degradation - Zhu, Hui; Zheng, Kai; Guo, Dagang; Zang, Hang; Yu, Sen; Xu, Kewei (Applied Surface Science, 2020)
Controllable degradation behavior of hydroxyapatite (HA) plays a crucial role in successful long-term implantation of a bone tissue substitute. In this study, electron beam irradiation (EBI) was carried out as an efficient strategy to modify HA structure. The degradation characteristics, bioactivity and cell response of the irradiated HA were comprehensively evaluated. The results showed that EBI with absorbed dose of 3.42, 10.27 and 20.54 Gy did not introduce newly-formed phase or impurity, but created crystal defects and nanovoids, which were formed from oxygen deficiencies, into HA lattice with irradiation dose-dependence. The dissolution rate of the irradiated HA enhanced continuously with increasing irradiation dose, as a result of constantly increasing crystal defects and enlarging voids, where the main reactive sites for the degradation of HA formed. The Ca2+ and PO43- releasing of HA with the highest irradiation dose enhanced by 92.75% and 138.85% respectively compared to that of the pristine HA after 28 days’ immersion. SBF immersion results suggested the irradiated HA with raising EBI doses exhibited preferable performance in bioactivity as well. Moreover, the results from CCK-8 assay and SEM observation showed that the irradiated HA were beneficial to the proliferation and attachment of osteoblasts.
CRIS-Team Scopus Importer:2020-07-10
Keywords: Cell compatibility; Crystal defect; Electron beam irradiation; Hydroxyapatite; In vitro dissolution

Engineering of Metabolic Pathways by Artificial Enzyme Channels. - Pröschel, Marlene; Detsch, Rainer; Boccaccini, Aldo R.; Sonnewald, Uwe (Frontiers in Bioengineering and Biotechnology, 2015)
Application of industrial enzymes for production of valuable chemical compounds has greatly benefited from recent developments in Systems and Synthetic Biology. Both, in vivo and in vitro systems have been established, allowing conversion of simple into complex compounds. Metabolic engineering in living cells needs to be balanced which is achieved by controlling gene expression levels, translation, scaffolding, compartmentation, and flux control. In vitro applications are often hampered by limited protein stability/half-life and insufficient rates of substrate conversion. To improve stability and catalytic activity, proteins are post-translationally modified and arranged in artificial metabolic channels. Within the review article, we will first discuss the supramolecular organization of enzymes in living systems and second summarize current and future approaches to design artificial metabolic channels by additive manufacturing for the efficient production of desired products.

Engineering peptide-modified alginate-based bioinks with cell-adhesive properties for biofabrication - Karakaya, Emine; Gleichauf, Luisa; Schöbel, Lisa; Hassan, Ahmed; Ahmadi Soufivand, Anahita; Tessmar, Joerg; Budday, Silvia; Boccaccini, Aldo R.; Detsch, Rainer (RSC Advances, 2024)
Alginate (ALG) and its oxidised form alginate-dialdehyde (ADA) are highly attractive materials for hydrogels used in 3D bioprinting as well as drop-on-demand (DoD) approaches. However, both polymers need to be modified using cell-adhesive peptide sequences, to obtain bioinks exhibiting promising cell-material interactions. Our study explores the modification of ALG- and ADA-based bioinks with the adhesive peptides YIGSR (derived from laminin), RRETEWA (derived from fibronectin) and IKVAV (derived from laminin) for 3D bioprinting. Two coupling methods, carbodiimide and Schiff base reactions, were employed to modify the polymers with peptides. Analytical techniques, including FTIR and NMR were used to assess the chemical composition, revealing challenges in confirming the presence of peptides. The modified bioinks exhibited decreased stability, viscosity, and stiffness, particularly-ADA-based bioinks in contrast to ALG. Sterile hydrogel capsules or droplets were produced using a manual manufacturing process and DoD printing. NIH/3T3 cell spreading analysis showed enhanced cell spreading in carbodiimide-modified ADA, Schiff base-modified ADA, and PEG-Mal-modified ADA. The carbodiimide coupling of peptides worked for ADA, however the same was not observed for ALG. Finally, a novel mixture of all used peptides was evaluated regarding synergistic effects on cell spreading which was found to be effective, showing higher aspect ratios compared to the single peptide coupled hydrogels in all cases. The study suggests potential applications of these modified bioinks in 3D bioprinting approaches and highlights the importance of peptide selection as well as their combination for improved cell-material interactions.
CRIS-Team Scopus Importer:2024-05-03

Engineering the surface functionality of 45S5 bioactive glass-based scaffolds by the heterogeneous nucleation and growth of silver particles - Meincke, Thomas; Miguez Pacheco, Valentina; Hoffmann, Daniel; Boccaccini, Aldo R.; Klupp Taylor, Robin (Journal of Materials Science, 2017)

Enhanced bacteriostatic activity, osteogenesis and osseointegration of silicon nitride/polyetherketoneketone composites with femtosecond laser induced micro/nano structural surface - Wu, Han; Liu, Tao; Xu, Zhiyan; Qian, Jun; Shen, Xuening; Li, Yuan; Pan, Yongkang; Wang, Deqiang; Zheng, Kai; Boccaccini, Aldo R.; Wei, Jie (Applied Materials Today, 2020)
Poor cell adhesion and osteogenic activity impede the bone regeneration and osseointegration effects of polyetherketoneketone (PEKK) implants. Surface modification and incorporation of bioactive fillers are effective strategies to promote the cellular responses of PEKK implants and their integration with bone tissues. In this study, silicon nitride (SN) microparticles were blended with PEKK to develop bioactive composite implants (SPC). Femtosecond laser was then used to modify SPC surfaces inducing favorable micro/nano structural surface (FSPC). After the laser ablation, irregularly shaped SN microparticles were converted to “petal-like” clusters composed of “pin-like” SN nanoparticles, while the entire surface was covered by SN particles due to the removal of PEKK. The roughness, hydrophilicity, content of surface chemical groups (e.g., -NH2), and protein adsorption capability of FSPC were significantly enhanced compared to SPC and PEKK. Also, the release of biologically active Si ions was increased after the femtosecond laser treatment, inducing a positive microenvironment favorable for cellular activities. Moreover, FSPC exhibited a greater bacteriostatic activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) than SPC. The presence of micro/nano structure also remarkably promoted adhesion, proliferation, and osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs). In vivo evaluation of the composites in a rabbit femur defect model verified that FSPC could enhance osteogenesis and osseointegration to a greater extent than SPC, evidenced with greater bone-implant contacts and push-out force. These results indicate that the femtosecond laser induced micro/nano structural surface on SN/PEKK implants can significantly promote osseointegration and bone repair. The femtosecond laser exhibits great potential in surface modifying bioceramic/polymer composites. The fabricated FSPC have shown great potential as bone implants in orthopedic applications considering their excellent biocompatibility, bacteriostatic property, osteogenic activity, and osseointegration.
CRIS-Team Scopus Importer:2019-12-20
Keywords: Femtosecond laser; Micro/nano structure; Osseointegration; Polyetherketoneketone; Silicon nitride

Enhancing alginate dialdehyde-gelatin (ADA-GEL) based hydrogels for biofabrication by addition of phytotherapeutics and mesoporous bioactive glass nanoparticles (MBGNs) - Bider, Faina; Gunnella, Chiara; Reh, Jana; Clejanu, Corina Elena; Kuth, Sonja; Beltrán, Ana M.; Boccaccini, Aldo R. (Journal of Biomaterials Applications, 2024)
This study explores the 3D printing of alginate dialdehyde-gelatin (ADA-GEL) inks incorporating phytotherapeutic agents, such as ferulic acid (FA), and silicate mesoporous bioactive glass nanoparticles (MBGNs) at two different concentrations. 3D scaffolds with bioactive properties suitable for bone tissue engineering (TE) were obtained. The degradation and swelling behaviour of films and 3D printed scaffolds indicated an accelerated trend with increasing MBGN content, while FA appeared to stabilize the samples. Determination of the degree of crosslinking validated the increased stability of hydrogels due to the addition of FA and 0.1% (w/v) MBGNs. The incorporation of MBGNs not only improved the effective moduli and conferred bioactive properties through the formation of hydroxyapatite (HAp) on the surface of ADA-GEL-based samples but also enhanced VEGF-A expression of MC3T3-E1 cells. The beneficial impact of FA and low concentrations of MBGNs in ADA-GEL-based inks for 3D (bio)printing applications was corroborated through various printing experiments, resulting in higher printing resolution, as also confirmed by rheological measurements. Cytocompatibility investigations revealed enhanced MC3T3-E1 cell activity and viability. Furthermore, the presence of mineral phases, as confirmed by an in vitro biomineralization assay, and increased ALP activity after 21 days, attributed to the addition of FA and MBGNs, were demonstrated. Considering the acquired structural and biological properties, along with efficient drug delivery capability, enhanced biological activity, and improved 3D printability, the newly developed inks exhibit promising potential for biofabrication and bone TE.
CRIS-Team Scopus Importer:2024-10-04
Keywords: 3D (bio)printing; bioactive glass particles; bone tissue engineering; drug delivery; Hydrogels; phytotherapeutic agent

Enhancing biological activity of bioactive glass scaffolds by inorganic ion delivery for bone tissue engineering - Mouriño, V.; Vidotto, R.; Cattalini, J. P.; Boccaccini, Aldo R. (Current Opinion in Biomedical Engineering, 2019)
This review covers recent research on therapeutic inorganic ions' (TIIs) ‘in situ’ delivery for bone repair and highlights some of the challenges involved, especially related to TII delivery in a controlled and sustained manner from bone tissue engineering (BTE) scaffolds. Strategies for the delivery of relevant biologically active ions with potential angiogenic and osteogenic effects in BTE approaches reported during the last five years are discussed, and the description of delivery techniques to meet bone regeneration requirements is presented. From early approaches using conventional bioceramics, the field has grown tremendously, driven in part by innovations in the biomaterials field, particularly bioactive glasses loaded with and capable to deliver TIIs. Modern advances in drug delivery applied to regenerative medicine focus on the rational design of scaffolds tailored for specific cargo and engineered to exert distinct biological functions. However, even though there is no release system universally suited to different TIIs, specific features and problems of one design or material type can shed light on how to approach TII release in BTE applications generally. Successful strategies to overcome current challenges will have broad application in bone regeneration with great promise for future clinical therapies.
CRIS-Team Scopus Importer:2019-10-29
Keywords: Bioactive glasses; Bone tissue engineering; Controlled release; Scaffolds; Therapeutic ions

Enhancing In Vitro Bioactivity of Melt-Derived 45S5 Bioglass® by Comminution in a Stirred Media Mill - Romeis, Stefan; Hoppe, Alexander; Eisermann, Claudia; Schneider, Nadine; Boccaccini, Aldo R.; Schmidt, Jochen; Peukert, Wolfgang (Journal of the American Ceramic Society, 2014)
45S5 Bioglassâ (45S5 BG) is a frequently applied Type A bioactive material, capable of forming an inherent bond to bone and soft tissue. Currently, applied melt-derived bioactive glass powders (BG) exhibit particle sizes between a few to several hundred micrometers. Recent studies on nanometer-sized bioactive glasses (nBGs), produced by bottom-up methods like sol– gel processing or flame spray pyrolysis, have indicated their great potential for several biomedical applications. In this study, the feasibility of top-down processing starting from bulk 45S5 BG by wet comminution in a stirred media mill was investigated. The products were assessed by in vitro hydroxycarbonate apatite (HCAp) formation in simulated body fluid, which is a marker for bioactive behavior. The study reveals the paramount influence of the used solvent for a successful topdown processing: In comparison with the as-received material bioactivity is lost for powders processed in water, preserved for comminution in ethanol and increased for powders processed using the alcohols n-butanol, n-pentanol, and n-hexanol. It was also found that only for the latter solvents, the chemical composition of the glass is maintained during comminution. Flakelike, slightly porous particles with specific surface areas of  25–30 m2/g are obtained. Thus, the presented comminution approach offers a convenient technique to process 45S5 BG with enhanced bioactivity.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.enhanc

Enhancing PEEK surface bioactivity: Investigating the effects of combining sulfonation with sub-millimeter laser machining - Chayanun, Slila; Chanamuangkon, Theerapat; Boonsuth, Budsaraporn; Boccaccini, Aldo R.; Lohwongwatana, Boonrat (Materials Today Bio, 2023)
Due to its superior mechanical properties and chemical stability, Polyetheretherketone (PEEK) has emerged as an alternative to conventional metal implants. However, the bio-inertness of PEEK's surface has limited its applications. Ambient sulfonation has been adopted to enhance bioactivity, but its nanoscale topographic changes are insufficient for implant-bone interlock. To further improve bone-implant interlock, this study employs CO2 laser machining to create sub-millimeter (0.5 mm) grooves on PEEK's surface, aiming to encourage bone ingrowth and strengthen the implant-bone interface. This research investigated the physical and chemical properties and bio-interaction of PEEK surface modified by sulfonation (SPEEK), laser machining (L-PEEK), and combination of both technique (L-SPEEK). X-ray photoelectron spectroscopy (XPS) spectra revealed that sulfonation compensates for the surface chemical shift instigated by laser ablation, aligning the surface chemistry of L-SPEEK with that of SPEEK. Furthermore, L-PEEK surfaces presented pores with sizes ranging from 1 to 600 μm, while SPEEK surfaces exhibited pores between 5 and 700 nm. All tested samples demonstrated non-cytotoxicity, with L-SPEEK exhibiting the highest mineralization and ALP activity as 2 and 2.1 times that of intrinsic PEEK, after 21 days of incubation. Microscopic imaging reveals a notably higher extracellular content on L-SPEEK compared to the other groups. This study underscores the potential of combining sub-millimeter laser machining with sulfonation in enhancing early osteogenic markers, providing a promising pathway for future PEEK-based orthopedic applications.
CRIS-Team Scopus Importer:2023-08-11
Keywords: Laser etching; Osseointegration; Polyetheretherketone; Sulfonation; Surface modification

Enhancing the Antibacterial Properties of Chitosan Coatings: Ag@Chitosan and Chitosan from Insects - Marsico, Michela; Azari, Rezvan; Curcio, Mariangela; Teghil, Roberto; Triunfo, Micaela; Falabella, Patrizia; Boccaccini, Aldo R.; De Bonis, Angela (Coatings, 2024)
In this study, the electrophoretic deposition (EPD) technique was used to prepare chitosan-based coatings with enhanced antibacterial activity suitable for bone implant applications. We designed, prepared, and compared the physico-chemical and biological properties of coatings obtained with commercial chitosan, chitosan enriched with silver nanoparticles, and chitosan obtained from insects. With the aim to consider the issue of sustainability, silver nanoparticles were directly prepared in the chitosan solution by laser ablation via a liquid technique, avoiding the use of chemicals and limiting the production of wastes. Moreover, a sustainable source of chitosan, such as Hermetia Illucens exuviae, was considered. The EPD process was optimized by adjusting parameters like voltage and deposition time to achieve ideal coating thickness and adhesion. The prepared films were characterized by spectroscopic and microscopic techniques such as SEM, XRD, and FTIR. Antimicrobial tests against E. coli and S. aureus revealed that silver nanoparticles enhanced the antibacterial properties of the polymer, whereas the biological evaluation using the WST8 test on MG63 human osteoblast-like cells showed that all coatings were non-toxic. Finally, chitosan obtained from insect showed comparable properties with respect to the commercial polymer, suggesting it could replace seafood-derived chitosan in biomedical applications, whereas the Ag@chitosan composite demonstrated superior antibacterial activity without compromising its biocompatibility.
CRIS-Team Scopus Importer:2024-09-06
Keywords: Ag NPs; antibacterial activity; chitosan; coating; electrophoretic deposition

Enhancing the biological performance of bioactive glasses by combination with phytotherapeutic compounds - Ilyas, Kanwal; Boccaccini, Aldo R. (wiley, 2022)
Tissue engineering (TE) continues to encounter challenges, mainly associated with the effective interaction of biomaterials (scaffolds) with the human biological system. One important issue involves the design of biomaterials with enhanced biological properties and minimum rate of inflammation. Secondary metabolites extracted from medicinal plants are gaining attention for TE applications. In the last few years, research has been focused on the relatively novel approach of combining extracts from herbs (phytotherapeutic agents) with bioactive glasses (BGs) in order to achieve superior therapeutic effects and to modulate the biological performance of the resulting organic-inorganic systems for TE purposes. In this chapter, we present an overview of such BG-phytotherapeutic systems. The focus is on the development of phytotherapeutic compound incorporated BGs with superior biological activities. Summarizing research carried out on this type of organic-inorganic biomaterials, possible therapeutic applications of plant derived compounds (for example neem, curcumin, coumarin, daidzein, icariin, and lawsone) in combination with BGs are critically discussed. Moreover, the synergistic effects of phytotherapeutic agents and BG dissolution products on the biological properties of the new organic-inorganic systems are overviewed. It has been revealed that multifunctional combinations of BGs with phytotherapeutic compounds have great potential for both bone and soft TE. Systematic (in vivo) studies are required to assess the effective time dependent mutual biological effects of BGs and phytotherapeutic drugs in realistic conditions. Overall, the strategy of combining the properties of BGs with phytochemicals represents a cutting-edge approach toward the development of advanced biomaterials to promote tissue healing and/or regeneration.
CRIS-Team Scopus Importer:2024-12-16
Keywords: Antibacterial; Bioactive glasses; Drug delivery; Herbal; Phytotherapeutic; Tissue regeneration

Entwicklung anwendungsspezifischer Hydrogelkonzepte basierend auf der Kombination von Alginat, Gelatine und bioaktivem Glas für das Tissue Engineering - Sarker, Bapi (2015)
Tissue engineering approaches typically involve an exogenous extracellular matrix (ECM) called a scaffold, isolated cells and biochemical signals. The design of the suitable exogenous ECM is essential for the success of tissue engineering since it regulates cell behavior, cell phenotype and tissue-specific gene expression and can mimic the functions of the native ECM of the host tissue. Hydrogels are attractive materials to develop exogenous ECM for tissue engineering applications since they possess microstructure and basic properties that resemble the native ECM in addition to being biocompatible. Alginate is one of the most widely used hydrogel-based biomaterials for tissue engineering applications because of its favorable ionic gelation property at mild conditions, which is suitable for the encapsulation of living cells and biomolecules. However, the slow and uncontrolled degradation and poor cell adhesion properties of alginate limit its applicability in tissue engineering. In the present study, an experimental approach was developed to overcome the drawbacks of alginate by designing a novel class of hydrogel. An alginate-gelatin crosslinked (ADA-GEL) hydrogel was synthesized through covalent crosslinking of alginate di-aldehyde (ADA) with gelatin (GEL). Using this approach the degradation of the matrix was found to be enhanced due to oxidation of alginate, which was carried out for ADA synthesis. Moreover, degradation of ADA-GEL could be controlled by changing the ratio between ADA and GEL moieties. In this study, two cell culture models (2D and 3D) based on the developed hydrogels were investigated. A 2D cell culture study was carried out on hydrogel films, in which normal human dermal fibroblasts (NHDF) and rat bone marrow derived stem cells (rBMSCs) were studied. Viability, attachment, spreading and proliferation of fibroblasts were significantly increased on ADA-GEL of different compositions compared to pristine alginate. Moreover, in vitro cytocompatibility of ADA-GEL was found to increase with increasing gelatin content. Similar outcomes were also observed for rBMSCs on ADA-GEL with and without 0.1% (w/v) bioactive glass nanoparticles (nBG). Moreover, two different 3D models were studied for in vitro cell culture, namely, microencapsulation and scaffolding approach using freeze-drying techniques. The first approach focused on the fabrication of microcapsules from ADA–GEL. The microencapsulation of cells in biodegradable hydrogels offers numerous attractive features for a variety of biomedical applications including tissue engineering. Microcapsules from ADA-GEL hydrogels of different compositions were achieved by tailoring the oxidation degree of ADA, crosslinking degree of ADA-GEL and concentrations and compositions of the hydrogels. From the in vitro cell study it was established that ADA-GEL hydrogels of different compositions supported spreading, migration and proliferation of encapsulated human adipose-derived mesenchymal stem cells (hADSCs), which, however, were found to be enhanced with increasing gelatin content. The extensive spreading, high cell-cell and cell-material interactions of the cells encapsulated in the ADA-GEL hydrogels demonstrated in this study have not been achieved in alginate-based hydrogels before. Most importantly, osteogenic differentiation of hADSCs was achieved in ADA-GEL microcapsules of all compositions. A preliminary in vivo biocompatibility study was conducted (by collaborators) using a subcutaneous model in rat, in which no significant immune reaction was observed for ADA-GEL microcapsules with and without encapsulated rBMSCs. In analogy to the in vitro degradation study, in vivo degradation of ADA-GEL microcapsules was also apparent. In the second approach, freeze-dried scaffolds were fabricated from ADA-GEL without and with the addition of different amounts of bioactive glass (BG). The scaffolds were used as 3D templates for in vitro cell culture aiming at final applications in bone tissue engineering. Incorporation of bioactive glass into ADA-GEL drew significant effects on the properties of the hydrogel and hydrogel-derived scaffolds. Incorporation of BG enhanced the mechanical properties and in vitro bioactivity of ADA-GEL-derived scaffolds. Osteogenic differentiation of bone marrow stromal cell line (ST-2) was found to occur in the freeze-dried scaffolds even in the absence of any external osteogenic stimulating supplements. These outcomes make the developed materials promising candidates for applications in bone tissue engineering and warrant further in vivo investigations.; Forschungen zur Gewebezüchtung beinhalten typischerweise die Synthese der extrazellulären Matrix (EZM) auch Scaffolds genannt, das Verhalten isolierter Zellen und biochemischen Signalen. Eine geeignete EZM ist entscheidend für den Erfolg der Gewebezüchtung, da Sie das Zellverhalten den Phänotyp der Zelle und die Expression gewebespezifischer Gene reguliert sowie die Funktion der natürlichen EZM des Empfängergewebes imitiert. Hydrogele sind attraktive Materialien, um EZM bei der Gewebezüchtung zu erzeugen, da sie die Mikrostruktur und wesentlichen Eigenschaften der natürlichen EZM besitzen. Zusätzlich weisen sie eine hervorragende Biokompatibilität auf. Alginat ist für Anwendungen in der Gewebezüchtung eines der am häufigsten verwendeten hydrogelbasierten Biomaterialien. Aufgrund seiner vorteilhaften Eigenschaften hinsichtlich der ionischen Gelierung unter milden Bedingungen ermöglicht es die Verkapselung von lebenden Zellen sowie bioaktiven Molekülen. Die langsame und unkontrollierte Degradation sowie die unzureichende Zelladhäsion an Alginat limitiert jedoch dessen Anwendbarkeit in der regenerativen Medizin. In dieser Arbeit wurden Versuche entwickelt, um das Alginat hinsichtlich seiner nachteiligen Eigenschaften zu verbessern. Durch die kovalente Bindung von Alginat Dialdehyd (ADA) mit Gelatine (GEL) wurde ein vernetztes Alginat-Gelatine (ADA-GEL) Hydrogel hergestellt. Durch die Oxidation des Alginats wurde die Degradation der Matrix optimiert. Ferner kann das Degradationsverhalten von ADA-GEL durch die Variation des Verhältnisses der funktionellen Gruppen des ADA und der GEL eingestellt werden. In dieser Arbeit wurden zwei Zellkulturmodelle (2D und 3D) mit den entwickelten Hydrogelen untersucht. Die 2D Zellkulturstudie wurde an Hydrogelfilmen durchgeführt, wobei normale humane dermale Fibroblasten (NHDF) und mesenchymale Stammzellen aus dem Knochenmark von Ratten (rBMSCs) analysiert wurden. Im Vergleich zum nicht modifizierten Alginat waren die Vitalität, die Adhäsion, die Spreitung und die Proliferation der Zellen bei verschiedenen Zusammensetzungen des ADA-GELs signifikant verbessert. Weiterhin wurde deutlich, dass die in-vitro Zytokompatibilität von ADA-GEL mit einem steigenden Anteil von Gelatine zunimmt. Ähnliche Resultate wurden für die rBMSCs auf ADA-GEL mit und ohne 0.1% (w/v) nanoskaliger bioaktiver Glaspartikel (nBG) erzielt. Desweiteren wurden zwei verschiedene 3D Modelle für in vitro Zellkulturuntersuchungen herangezogen, nämlich der Ansatz der Mikroverkapselung sowie die Herstellung von Stützgerüsten mit Hilfe der Gefriertrocknungstechnik. Das erste Konzept zielte auf die Herstellung von Mikrokapseln aus ADA-GEL. Die Mikroverkapselung von Zellen in biodegradierbaren Hydrogelen eröffnet zahlreiche Möglichkeiten für eine Vielzahl an biomedizinischen Anwendungen einschließlich der Gewebezüchtung. Durch die Anpassung des Oxidationsgrades von ADA, des Vernetzungsgrades von ADA-GEL und der Konzentration sowie der Zusammensetzung der Hydrogele wurden Mikrokapseln aus ADA-GEL mit verschiedenen Zusammensetzungen gezielt optimiert. Durch die in vitro Zellstudie wurde gezeigt, dass ADA-GEL Hydrogele mit verschiedenen Zusammensetzungen die Spreitung, Migration und Proliferation von verkapselten humanen aus dem Fettgewebe gewonnenen mesenchymalen Stammzellen (hADSCs) stimulieren, was durch die Erhöhung des Gelatineanteils noch gesteigert werden konnte. Die ausgiebige Spreitung, eine hohe Zell-Zell und Zell-Material Wechselwirkung der im ADA-GEL verkapselten Zellen, konnten durch Alginat-basierte Hydrogele vorher nicht erreicht werden. Besonders hervorzuheben ist die osteogene Differenzierung von hADSCs in ADA-GEL Mikrokapseln aller Zusammensetzungen. Ein Vorversuch der in vivo Biokompatibilitätsstudie wurde (von Kollaborateuren) unter Verwendung eines subkutanen Modells an Ratten durchgeführt, wobei keine signifikante Immunreaktion für ADA-GEL Mikrokapseln mit und ohne eingekapselte rBMSCs festgestellt wurde. Analog zur in vitro Degradationsstudie, war auch in vivo Degradation die ADA-GEL Mikrokapseln zu beobachten. In einem zweiten Ansatz wurden gefriergetrocknete ADA-GEL Scaffolds mit und ohne bioaktivem Glas (BG) hergestellt. Die Scaffolds wurden als 3D Gerüststrukturen für in vitro Zellkulturuntersuchungen herangezogen, mit dem Ziel, diese in der Knochengewebezüchtung einzusetzen. Das Einbringen von bioaktivem Glas in ADA-GEL führte zu signifikanten Effekten hinsichtlich der Eigenschaften des Hydrogels und der aus diesem hergestellten Scaffolds. Die Zugabe von BG erhöhte die mechanischen Eigenschaften und die in vitro Bioaktivität von ADA-GEL Scaffolds. Es zeigte sich, dass es in den gefriergetrockneten Scaffolds zur osteogenen Differenzierung der Knochenmark Stroma Zelllinie (ST-2) kommt, obwohl keine externen Zusätze zur osteogenen Differenzierung verwendet wurden. Diese Ergebnisse zeigen, dass die entwickelten Materialien vielversprechende Kandidaten für den Einsatz im Knochen Tissue engineering sind, erfordern jedoch weitere in vivo Untersuchungen.
Keywords: Dissertation; Gelatin; Hydrogels; Tissue Engineering; Alginate

Environmentally friendly fabrication of electrospun nanofibers made of polycaprolactone, chitosan and k-carrageenan (PCL/CS/k-C) - Vargas Osorio, Zulema; Ruther, Florian; Chen, Si; Sengupta, Susanta; Liverani, Liliana; Michalek, Martin; Galusek, Dušan; Boccaccini, Aldo R. (Biomedical Materials, 2022)
Electrospun fibers based on biodegradable polyanionic or polycationic biopolymers are highly beneficial for biomedical applications. In this work, electrospun nanofibers made from poly(epsilon caprolactone) (PCL), chitosan (CS) and k-carrageenan (k-C) were successfully fabricated using several mixtures of benign solvents containing formic acid and acetic acid. The addition of k-C improved the preparation procedure for the production of PCL/CS fibers by electrospinning. Moreover, a polymer mixture was selected to be stored at -20 degrees C for one month with the purpose to study the properties of the resulting fiber mat. The results indicated that fiber characteristics were not seriously compromised compared to the ones of those fabricated with the original solution, which represents an important reduction in produced waste. Thus, the interactions that occur between positively and negatively charged hydrophilic polysaccharides might induce higher stability to the linear aliphatic polyester in the polymer mixture. All fiber mats were morphologically, physico-chemically and mechanically characterized, showing average fiber diameters in the nano scale. A direct cell viability assay using ST-2 cells demonstrated cell proliferation after seven days of incubation for all prepared fiber mats, confirming their suitability as potential candidates for bone tissue engineering and wound healing applications.
CRIS-Team WoS Importer:2022-06-17

Enzymatic Insitu Crosslinking Can Improve Hydrogel Stability While Maintaining Matrix Stiffness - Kuth, Sonja; Boccaccini, Aldo R. (ChemistrySelect, 2024)
Next to the choice of a material, the crosslinking characteristics play an important role in the development of hydrogels for applications in the biomedical field. By decreasing crosslinking time or concentration one can reduce the density of the network and hence the stiffness of the hydrogel. However, at the same time in many cases the stability of the matrix is significantly reduced, leading to a rapidly degrading hydrogel structure. In this study, we evaluate and compare two different crosslinking methods while maintaining the material chemistry. The hydrogel system evaluated consisted of oxidized hyaluronic acid and gelatin, and it was crosslinked with microbial transglutaminase. We found that by in situ crosslinking (CL) instead of post CL we can significantly increase the stability of the hydrogel while maintaining the matrix stiffness. Encapsulated embryonic mouse fibroblasts showed an increased viability in in situ crosslinked samples. These findings indicate that it is possible to change hydrogel parameters independently, even if they are otherwise interrelated.
CRIS-Team Scopus Importer:2024-09-06
Keywords: Enzymes; Hyaluronic acid; Hydrogel; Microbial transglutaminase; Oxidation

Erosion protective coatings for low density, highly porous carbon/carbon composites - Smeacetto, F.; Salvo, M.; Ferraris, M.; Casalegno, V.; Canavese, Giancarlo; Moskalewicz, Tomasz; Ellacott, S.; Rawlings, R. D.; Boccaccini, Aldo R. (Carbon, 2009)
A simple and low cost method based on slurry coating was used to produce silicon carbide, titanium carbide and glass-ceramic coatings on low density carbon/carbon composites in order to improve their erosion resistance. Microstructural analyses were performed for substrate and coatings by optical microscopy, and scanning and transmission electron microscopy. As-received and coated composites were submitted to erosion tests using a sandblasting machine according to ASTM G76-95. The best results were obtained with a silica-alumina-yttria based glass-ceramic coating. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.erosio

Erratum: 45S5 bioactive glass-based scaffolds coated with cellulose nanowhiskers for bone tissue engineering (RSC Adv. (2014) 4 (56156-56164) DOI: 10.1039/C4RA07740G) - Li, Wei; Garmendia, Nere; De Larraya, Uxua Perez; Ding, Yaping; Detsch, Rainer; Grünewald, Alina; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (RSC Advances, 2023)
The authors regret unattributed data overlap between their RSC Advances article and ref. 1. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.
CRIS-Team Scopus Importer:2023-05-26

Erratum to: Bioactive layers based on black glasses on titanium substrates (Journal of the American Ceramic Society, (2018), 101, 2, (590-601), 10.1111/jace.15202) - Gaweda, Magdalena; Jelen, Piotr; Dlugon, Elzbieta; Wajda, Aleksandra; Lesniak, Magdalena; Simka, Wojciech; Sowa, Maciej; Detsch, Rainer; Boccaccini, Aldo R.; Sitarz, Maciej (Journal of the American Ceramic Society, 2018)
In the published article listed above, the last sentence of the Introduction should be changed from “To the best of our knowledge, there is no work devoted to the study of the bioactivity and biocompatibility of black glasses.” to the corrected version, which is “The bioactivity and cytocompatibility of silicon oxycarbide monoliths and powders have been investigated previously, however, to the best of our knowledge, there is no previous work devoted to the study of the bioactivity and biocompatibility of black glasses as coatings of titanium substrates.” In addition, the sentence should include citation of the reference “Gonzalo-Juan I, Detsch R, Mathur S, Ionescu E, Boccaccini AR, Riedel R. Synthesis and in vitro activity assessment of novel silicon oxycarbide-based bioactive glasses. Materials. 2016;9(12):959-969”.
CRIS-Team Scopus Importer:2022-08-05

Essential oils in biomedical applications: Recent progress and future opportunities - Ünalan, Irem; Boccaccini, Aldo R. (Current Opinion in Biomedical Engineering, 2021)
The use of essential oils (EOs) combined with engineered biomaterials has been continuously growing. Research has focused on counteracting drawbacks of EOs such as volatility, relative low stability, and high sensitivity to environmental factors, in addition to investigating biological effects of EOs. This review discusses recent developments in the use of EOs in biomedical applications, such as antibacterial materials, drug delivery systems, and wound healing. Furthermore, we summarize not only the antibacterial and biological activities of biomaterial–EO combinations, but also discuss the effects of EOs on physical, thermal, and mechanical properties of biomaterials, which distinguishes this review from previous similar articles. EOs discussed are cinnamon, clove, and peppermint. Results show that the incorporation of EOs in engineered biomaterials has led to improved antibacterial activity, biocompatibility, and wound healing in several systems. Biomaterial–EO combinations represent a promising alternative for a new generation of hybrid biomedical systems incorporating natural medicinal compounds in engineered biomaterials.
CRIS-Team Scopus Importer:2021-03-05
Keywords: Composites; Essential oils; Hybrid biomaterials; Natural medical products

Eu2+ and Eu3+ based "concentrated phosphors" as converters for UV LED light: two approaches and two new examples - Batentschuk, Miroslaw; Geisler, R.; Hum, Jasmin; Iqbal, Farasat; Meister, Frank; Osvet, Andres; Stiegelschmitt, Alfons; Winnacker, Albrecht (Applied Physics B-Lasers and Optics, 2012)
The absolute majority of phosphors are composed of a host lattice and some percentage of an activator. At higher activator concentrations the concentration quenching occurs. However, there are phosphors in which only minor quenching of the emission occurs with increasing of the activator content. Based on the existence of two different valence states of the Eu ion (2+ and 3+), two approaches for the development of "concentrated phosphors", i.e. light emitting materials in which the activator ion is a main part of the crystal lattice, are discussed. In both approaches, reduced energy migration leading to the luminescence quenching is considered as a main condition to reach a high quantum efficiency of a concentrated phosphor. Two kinds of phosphors-Eu2+-doped alumosilicate and Eu3+-doped oxyfluoride-are used as an experimental basis for this discussion. Starting from the stoichiometric Ca1-x Eu-x(2+) A1(2)si(2)O8 anorthite and Eu3+OF oxyfluorides, the non-stoichiometric powders with Eu-0.92(2+) A1(1.76)Si(2.24)O(8), Eu3+(O, F)(2,35) and Eu3+(O, F)(2,16) compositions were synthesized by a solid state reaction and investigated. It was shown that-in spite of the almost 100% Eu concentration-light converters with high quantum efficiency of more than 45% can be realized. A possible application of these materials as UV LED light converters for white light emitting diodes are discussed as well.

Evaluation of an alginate-gelatine crosslinked hydrogel for bioplotting - Zehnder, Tobias; Sarker, Bapi; Boccaccini, Aldo R.; Detsch, Rainer (Biofabrication, 2015)
Using additive manufacturing to create hydrogel scaffolds which incorporate homogeneously distributed, immobilized cells in the context of biofabrication approaches represents an emerging and expanding field in tissue engineering. Applying hydrogels for additive manufacturing must consider the material processing properties as well as their influence on the immobilized cells. In this work alginate-dialdehyde (ADA), a partially oxidized alginate, was used as a basic material to improve the physico-chemical properties of the hydrogel for cell immobilization. At first, the processing ability of the gel using a bioplotter and the compatibility of the process with MG-63 osteoblast like cells were investigated. The metabolic and mitochondrial activities increased at the beginning of the incubation period and they balanced at a relatively high level after 14-28 days of incubation. During this incubation period the release of vascular endothelial growth factor-A also increased. After 28 days of incubation the cell morphology showed a spreading morphology and cells were seen to move out of the scaffold struts covering the whole scaffold structure. The reproducible processing capability of alginate-gelatine (ADA-GEL) and the compatibility with MG-63 cells were proven, thus the ADA-GEL material is highlighted as a promising matrix for applications in biofabrication.

Evaluation of angiogenesis of bioactive glass in the arteriovenous loop model - Arkudas, Andreas; Balzer, Amelie; Bührer, Gregor; Arnold, Isabel; Hoppe, Alexander; Detsch, Rainer; Newby, Phillipa; Fey, Tobias; Greil, Peter; Horch, Raymund E.; Boccaccini, Aldo R.; Kneser, Ulrich (Tissue Engineering - Part C: Methods, 2013)
In this study, the angiogenetic effect of sintered 45S5 Bioglass (R) was quantitatively assessed for the first time in the arteriovenous loop (AVL) model. An AVL was created by interposition of a venous graft from the contralateral side between the femoral artery and vein in the medial thigh of eight rats. The loop was placed in a Teflon isolation chamber and was embedded in a sintered 45S5 Bioglass (R) granula matrix filled with fibrin gel. Specimens were investigated 3 weeks postoperatively by means of microcomputed tomography, histological, and morphometrical techniques. All animals tolerated the operations well. At 3 weeks, both microcomputed tomography and histology demonstrated a dense network of newly formed vessels originating from the AVL. All constructs were filled with cell-rich, highly vascularized connective tissue around the vascular axis. Analysis of vessel diameter revealed constant small vessel diameters, indicating immature new vessel sprouts. This study shows for the first time axial vascularization of a sintered 45S5 Bioglass (R) granula matrix. After 3 weeks, the newly generated vascular network already interfused most parts of the scaffolds and showed signs of immaturity. The intrinsic type of vascularization allows transplantation of the entire construct using the AVL pedicle.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.evalua

Evaluation of antibacterial and cytotoxic effects of nano-sized bioactive glass/collagen composites releasing tetracycline hydrochloride - Rivadeneira, J.; Di Virgilio, A. L.; Audisio, M. C.; Boccaccini, Aldo R.; Gorustovich, A. A. (Journal of Applied Microbiology, 2014)
Aims: To evaluate the antibacterial efficacy of silicate bioactive glass nanoparticles/collagen composites functionalized with tetracycline hydrochloride (TCH). Methods and Results: Different concentrations of tetracycline hydrochloride (TCH) were incorporated on silicate bioactive glass nanoparticles/collagen composites by dipping these biomaterials for 48 h at 37°C in a solution of simulated body fluid (SBF) plus 0·05, 0·20 or 0·35 mg ml of the antibiotic. TCH release was assessed in double-distilled water at 37°C up to 72 h. The antibacterial activity of the samples has been evaluated in two ways: inhibition zone test and plate count method. The experiments were performed in vitro up to 48 h on four staphylococci strains (Staphylococcus aureus ATCC29213, ATCC25923, ATCC6538P and Staphylococcus epidermidis ATCC12228). The new composites were also tested for cytotoxicity on MG-63 human osteosarcoma cells. The results showed that the incorporation and release of TCH was dependent on the initial concentration of TCH in SBF. The biomaterials also inhibited the Staph. aureus cell growth even though the efficacy was similar for all concentration. On the other hand, no cytotoxic effects were found on osteoblast-like cells, even at the highest concentration. Conclusions: Considering all results, it can be concluded that the new composite acts as a suitable bioactive carrier of TCH and could have potential in the prevention of biomaterial related infections. Significance and Impact of the Study: The results suggest a potential application as wound dressing. © 2014 The Society for Applied Microbiology.
Keywords: Antibacterial activity; Antibiotic; Bioactive glass; Collagen

Evaluation of cell inkjet printing technique for biofabrication - Detsch, Rainer; Blob, Sebastian; Zehnder, Tobias; Boccaccini, Aldo R. (BioNanoMaterials, 2016)
Keywords: biofabrication; cell printing; inkjet technique

Evaluation of electrospun poly(ε-caprolactone)/gelatin nanofiber mats containing clove essential oil for antibacterial wound dressing - Ünalan, Irem; Endlein, Stefan J.; Slavik, Benedikt; Büttner, Andrea; Goldmann, Wolfgang; Detsch, Rainer; Boccaccini, Aldo R. (Pharmaceutics, 2019)
The objective of this study was to produce antibacterial poly(ε-caprolactone) (PCL)-gelatin (GEL) electrospun nanofiber mats containing clove essential oil (CLV) using glacial acetic acid (GAA) as a “benign” (non-toxic) solvent. The addition of CLV increased the fiber diameter from 241 ± 96 to 305 ± 82 nm. Aside from this, the wettability of PCL-GEL nanofiber mats was increased by the addition of CLV. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the presence of CLV, and the actual content of CLV was determined by gas chromatography–mass spectrometry (GC-MS). Our investigations showed that CLV-loaded PCL-GEL nanofiber mats did not have cytotoxic effects on normal human dermal fibroblast (NHDF) cells. On the other hand, the fibers exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli. Consequently, PCL-GEL/CLV nanofiber mats are potential candidates for antibiotic-free wound healing applications.
CRIS-Team Scopus Importer:2019-11-15
Keywords: Antibacterial; Biocompatibility; Clove essential oil; Electrospinning; Gelatin; PCL

Evaluation of fibroblasts adhesion and proliferation on alginate-gelatin crosslinked hydrogel - Sarker, Bapi; Singh, Raminder; Silva, Raquel; Roether, Judith; Kaschta, Joachim; Detsch, Rainer; Schubert, Dirk W.; Cicha, Iwona; Boccaccini, Aldo R. (PLoS ONE, 2014)
Due to the relatively poor cell-material interaction of alginate hydrogel, alginate-gelatin crosslinked (ADA-GEL) hydrogel was synthesized through covalent crosslinking of alginate di-aldehyde (ADA) with gelatin that supported cell attachment, spreading and proliferation. This study highlights the evaluation of the physico-chemical properties of synthesized ADA-GEL hydrogels of different compositions compared to alginate in the form of films. Moreover, in vitro cell-material interaction on ADA-GEL hydrogels of different compositions compared to alginate was investigated by using normal human dermal fibroblasts. Viability, attachment, spreading and proliferation of fibroblasts were significantly increased on ADA-GEL hydrogels compared to alginate. Moreover, in vitro cytocompatibility of ADA-GEL hydrogels was found to be increased with increasing gelatin content. These findings indicate that ADA-GEL hydrogel is a promising material for the biomedical applications in tissue-engineering and regeneration. Copyright:

Evaluation of hydrogel matrices for vessel bioplotting: Vascular cell growth and viability - Singh, Raminder; Sarker, Bapi; Silva, Raquel; Detsch, Rainer; Dietel, Barbara; Alexiou, Christoph; Boccaccini, Aldo R.; Cicha, Iwona (Journal of Biomedical Materials Research Part A, 2015)
Developing matrices biocompatible with vascular cells is one of the most challenging tasks in tissue engineering. Here, we compared the growth of vascular cells on different hydrogels as potential materials for bioplotting of vascular tissue. Formulations containing alginate solution (Alg, 2%, w/v) blended with protein solutions (silk fibroin, gelatin, keratin, or elastin) at 1% w/v were prepared. Human umbilical vein endothelial cells (ECs), smooth muscle cells (SMCs), and fibroblasts were cultivated on hydrogels for 7 days. Cell number and morphology was visualised using fluorescent staining at day 3 and 7. Cell metabolic activity was analysed using WST assay. Compared to pure Alg, Alg/keratin, Alg/gelatin and Alg/silk fibroin provided superb surfaces for ECs, supporting their attachment, growth, spreading and metabolic activity. SMCs showed best colonization and growth on Alg/silk fibroin and Alg/keratin hydrogels, whereas on elastin-containing hydrogels, cell clustering was observed. Fibroblasts growth was enhanced on Alg/elastin, and strongly improved on silk fibroin- and keratin-containing hydrogels. In contrast to the previous studies with alginate dialdehyde-gelatin crosslinked gels, Alg/gelatin blend hydrogels provided a less favourable scaffold for fibroblasts. Taken together, the most promising results were obtained with silk fibroin- and keratin-containing hydrogels, which supported the growth of all types of vascular cells.
Keywords: alginate-protein hydrogels; biocompatibility; fibroblasts; scaffold endothelialisation; smooth muscle cells

Evaluation of in vitro properties of 3D micro-macro porous zirconia scaffolds coated with 58S bioactive glass using MG-63 osteoblast-like cells - Mesquita-Guimaraes, J.; Ramos, L.; Detsch, Rainer; Henriques, B.; Fredel, M. C.; Silva, F. S.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2019)
A new family of bioceramic scaffolds consisting of zirconia foam-like structures with 58S bioactive glass (BG) coating was developed. Three open-cell structures fabricated by the foam replica method were coated via immersion in a sol-gel solution. The coating technique was optimised controlling the sol viscosity, condensation time, and the number of immersions in order to increase the coating thickness. The scaffolds chemical and structural characteristics were evaluated before in vitro tests, including the Ca/P ratio, crystalline phase composition, pH change, pore diameter and microporosity of the scaffolds struts. In vitro tests were performed by culturing MG-63 human osteoblast-like cells. An increase in cell proliferation of 100% was found with the decrease in pore size from 700 to 120 mu m. Also, with the presence of the 58S-BG coating, an increase of cell proliferation was reached, which indicates the positive effect of the BG coating on the otherwise bioinert ceramic scaffold.
CRIS-Team WoS Importer:2019-04-16

Evaluation of mechanical properties, in vitro corrosion resistance and biocompatibility of Gum Metal in the context of implant applications - Golasiński, Karol Marek; Detsch, Rainer; Szklarska, Magdalena; Łosiewicz, Bożena; Zubko, Maciej; Mackiewicz, Sławomir; Pieczyska, Elżbieta Alicja; Boccaccini, Aldo R. (Journal of the Mechanical Behavior of Biomedical Materials, 2021)
In recent decades, several novel Ti alloys have been developed in order to produce improved alternatives to the conventional alloys used in the biomedical industry such as commercially pure titanium or dual phase (alpha and beta) Ti alloys. Gum Metal with the non-toxic composition Ti–36Nb–2Ta–3Zr–0.3O (wt. %) is a relatively new alloy which belongs to the group of metastable beta Ti alloys. In this work, Gum Metal has been assessed in terms of its mechanical properties, corrosion resistance and cell culture response. The performance of Gum Metal was contrasted with that of Ti–6Al–4V ELI (extra-low interstitial) which is commonly used as a material for implants. The advantageous mechanical characteristics of Gum Metal, e.g. a relatively low Young's modulus (below 70 GPa), high strength (over 1000 MPa) and a large range of reversible deformation, that are important in the context of potential implant applications, were confirmed. Moreover, the results of short- and long-term electrochemical characterization of Gum Metal showed high corrosion resistance in Ringer's solution with varied pH. The corrosion resistance of Gum Metal was best in a weak acid environment. Potentiodynamic polarization studies revealed that Gum Metal is significantly less susceptible to pitting corrosion compared to Ti–6Al–4V ELI. The oxide layer on the Gum Metal surface was stable up to 8.5 V. Prior to cell culture, the surface conditions of the samples, such as nanohardness, roughness and chemical composition, were analyzed. Evaluation of the in vitro biocompatibility of the alloys was performed by cell attachment and spreading analysis after incubation for 48 h. Increased in vitro MC3T3-E1 osteoblast viability and proliferation on the Gum Metal samples was observed. Gum Metal presented excellent properties making it a suitable candidate for biomedical applications.
CRIS-Team Scopus Importer:2021-01-29
Keywords: Gum Metal; Implant applications; In vitro biocompatibility; In vitro corrosion resistance; Mechanical behavior

Evaluation of plasma trace element and mineral status in children and adolescents with phenylketonuria using data from inductively-coupled-plasma atomic emission and mass spectrometric analysis - Knerr, Ina; Blessing, Holger; Seyferth, Stefan; Watling, R J; Chaudhri, Anwar (Annals of Nutrition and Metabolism, 2013)
Background: Phenylketonuria (PKU) is caused by a severe phenylalanine hydroxylase deficiency; the mainstay of treatment is a low-phenylalanine diet. A diet which is so restrictive is associated with a risk of nutritional deficiencies. We investigated plasma concentrations for 46 elements, including minerals and trace elements. Methods: We enrolled 20 children and adolescents with PKU and 20 matched controls. Multi-elementary quantification was carried out by solution-based inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ICP mass spectrometry (ICP-MS). Results: With the exception of manganese and aluminium, no significant differences were found for element levels between PKU patients and controls. As a trend, manganese levels were lower in PKU patients than in control subjects (p < 0.05) but were within the reference range. There was a positive linear relationship between manganese and tyrosine levels in subjects with PKU (r = 0.2295, p < 0.05). If detectable, potentially toxic elements were only identified in ultra-trace quantities in plasma samples of either group; aluminium levels were found to be slightly higher in PKU subjects than in controls (p < 0.01). Conclusion: The combination of ICP-AES and ICP-MS data is a useful diagnostic tool for element quantification at a high analytical rate and for monitoring bio-element status, e.g. in patients on a restrictive diet. Copyright © 2013 S. Karger AG, Basel.

Evaluation of silica-nanotubes and strontium hydroxyapatite nanorods as appropriate nanoadditives for poly(butylene succinate) biodegradable polyester for biomedical applications - Grigoriadou, I.; Nianias, N.; Hoppe, Alexander; Terzopoulou, Z.; Bikiaris, D.; Will, Julia; Hum, Jasmin; Roether, Judith; Detsch, Rainer; Boccaccini, Aldo R. (Composites Part B-Engineering, 2014)
In the present study two series of poly(butylene succinate) (PBSu) nanocomposites containing 5 and 20 wt% of silica-nanotubes or strontium hydroxyapatite [Sr(PO)OH] nanorods were prepared by melt mixing at 130 C. From SEM images it was found that SiO nanotubes are well dispersed inside the PBSu matrix while Sr (PO)OH nanorods formed some aggregates. In both cases the mechanical properties of nanocomposites were slightly affected by the amount of nanoadditives. Enzymatic hydrolysis of PBSu and its nanocomposites was studied in aqueous solutions containing a mixture of R. delemar and Pseudomonas Cepacia lipases, at 50 C and pH = 7.2. It was found that all nanocomposites have higher hydrolysis rates than neat PBSu indicating that nanoparticles accelerate the hydrolysis degradation process. The hydrophilicity of nanofillers, the presence of hydroxyl groups and the effect of a ''gap" at the interface due to low adhesion of PBSu matrix and inorganic nanofillers, could increase the enzymatic hydrolysis rate of the polyester matrix. All prepared samples were tested in relevant cell culture using osteoblast-like cells (MG-63) to demonstrate their biocompatibility. It was found that SiO nanotubes support cell attachment, while Sr(PO )OH nanorods decrease cell activity. © 2013 Elsevier Ltd. All rights reserved.
Keywords: A. Discontinuous reinforcement; A. Nano-structures; B. Mechanical properties; B. Microstructures; B. Surface properties

Evaluation of the antibacterial effects of vancomycin hydrochloride released from agar-gelatin-bioactive glass composites - Rivadeneira, Josefina; Laura Di Virgilio, Ana; Carina Audisio, M.; Boccaccini, Aldo R.; Gorustovich, Alejandro A. (Biomedical Materials (Bristol), 2015)
The aim of this work was to evaluate the perfomance of agar-gelatin (AG) composites and AG-containing 45S5 bioactive glass (BG) microparticles (AGBG) in relation to their water uptake capacity, sustained release of a drug over time, and antibacterial effects. The composites were fabricated by the gel-casting method. To impart the local drug release capacity, vancomycin hydrochloride (VC) was loaded in the composites in concentrations of 0.5 and 1 mg ml. VC release was assessed in distilled water at 37 °C up to 72 h and quantified spectrophotometrically. The antibacterial activity of composites was evaluated by the inhibition zone test and the plate count method. The experiments were performed in vitro up to 48 h on three staphylococcus strains: Staphylococcus aureus ATCC29213, S. aureus ATCC6538 and Staphylococcus epidermidis ATCC12228. The results showed that the addition of BG to AG composites did not affect the degree of water uptake. The release of VC was significantly affected by the presence of BG. VC release was higher from AGBGVC films than from AGVC ones over prolonged incubation times. Bacterial inhibition zones were found around the composites. The halos were larger when the cells were put in contact with AGVC composites than when they were put in contact with AGBGVC ones. Nevertheless, the viable count method demonstrated that the composites inhibited Staphylococcus cell growth with no statistical differences. In conclusion, the addition of BG did not reflect an improvement in the parameters studied. On the other hand, composites loaded with VC would have a role in prophylaxis against bacterial infection.
Keywords: bioactive glass; biopolymers; staphylococci; vancomycin hydrochloride

Exploiting Bisphosphonate–Bioactive-Glass Interactions for the Development of Self-Healing and Bioactive Composite Hydrogels - Diba, Mani; An, Jie; Schmidt, Stephan; Hembury, Mathew; Ossipov, Dmitri; Boccaccini, Aldo R.; Leeuwenburgh, Sander C. G. (Macromolecular Rapid Communications, 2016)
Keywords: bioactive glasses; bisphosphonates; hydrogels; self-healing; tissue engineering

Expression of Concern - Boccaccini, Aldo R. (Materials Letters, 2019)
CRIS-Team WoS Importer:2019-07-26

Extensive reuse of soda-lime waste glass in fly ash-based geopolymers - Toniolo, Nicoletta; Rincon, Acacio; Roether, Judith; Ercole, P.; Bernardo, E.; Boccaccini, Aldo R. (Construction and Building Materials, 2018)
Keywords: Geopolymers; Waste glass; Fly ash

Extracellular and intracellular effects of bioactive glass nanoparticles on osteogenic differentiation of bone marrow mesenchymal stem cells and bone regeneration in zebrafish osteoporosis model - Meng, Li; Zhao, Panpan; Jiang, Yucheng; You, Jiawen; Xu, Zhiyan; Yu, Kui; Boccaccini, Aldo R.; Ma, Junqing; Zheng, Kai (Acta Biomaterialia, 2024)
Bioactive glass nanoparticles (BGNs) are well-recognized multifunctional biomaterials for bone tissue regeneration due to their capability to stimulate various cellular processes through released biologically active ions. Understanding the correlation between BGN composition and cellular responses is key to developing clinically usable BGN-based medical devices. This study investigated the influence of CaO content of binary SiO2-CaO BGNs (CaO ranging from 0 to 10 mol%) on osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and in vivo bone regeneration in zebrafish osteoporosis model. The results showed that BGNs could promote osteogenic differentiation of rBMSCs by indirectly releasing active ions or directly interacting with rBMSCs by internalization. In both situations, BGNs of a higher CaO content could promote the osteogenic differentiation of rBMSCs to a greater extent. The internalized BGNs could activate the transcription factors RUNX2 and OSX, leading to the expression of osteogenesis-related genes. The results in the zebrafish osteoporosis model indicated that the presence of BGNs of higher CaO contents could enhance bone regeneration and rescue dexamethasone-induced osteoporosis to a greater extent. These findings demonstrate that BGNs can stimulate osteogenic differentiation of rBMSCs by releasing active ions or internalization. A higher CaO content facilitates osteogenesis and bone regeneration of zebrafish as well as relieving dexamethasone-induced osteoporosis. The zebrafish osteoporosis model can be a potent tool for evaluating the in vivo bone regeneration effects of bioactive materials. Statement of significance: Bioactive glass nanoparticles (BGNs) are increasingly used as fillers of nanocomposites or as delivery platforms of active ions to regenerate bone tissue. Various studies have shown that BGNs can enhance osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by releasing active ions. However, the correlation between BGN composition and cellular responses and in vivo bone regeneration effect has still not been well investigated. Establishment of a suitable in vivo animal model for investigating this correlation is also challenging. The present study reports the influence of CaO content in binary SiO2-CaO BGNs on osteogenic differentiation of BMSCs extracellularly and intracellularly. This study also demonstrates the suitability of zebrafish osteoporosis model to investigate in vivo bone regeneration effect of BGNs.
CRIS-Team Scopus Importer:2024-01-12
Keywords: Bioactive glass; Bone regeneration; Cellular uptake; Osteoporosis; Zebrafish model

Extracellular matrix collagen-I fibrillar networks in bone tissue engineering – analysis with SHG and multiphoton microscopy - Vielreicher, Martin; Detsch, Rainer; Boccaccini, Aldo R.; Friedrich, Oliver (5th International Congress on Stem Cells and Tissue Formation (Deutsche Gesellschaft für Zytometrie, DGfZ), 2014)
Question: Bone Tissue Engineering: Do mesenchymal stem cells (MSC`s) form better and more collagen-I fibers in 3D vs 2D cell culture? Methods: MSC`s isolated from rat femur were tested in 2D (monolayers, biomaterial films) vs. 3D systems (pellet, hydrogel or scaffold cultures) and grown in normal or serum-reduced or in osteogenic medium (1% FBS). Bone tissue-relevant biomaterials were cross-linked alginate-gelatin, collagen-I, PCL and PCL-Bioglass. Cells were imaged with label-free and depthresolved multiphoton microscopy by their autofluorescence or nuclear/membrane stainings. Produced collagen-I fibers were detected using second harmonic generation (SHG) and, as control, immunofluorescence (IF). Parallel collagen-I detection occurred using Western Blotting (WB) after solubilization with pepsin at pH2. Results: WB and IF analysis showed that MSC`s formed collagen-I in both 2D and 3D systems in plain and biomaterial containing constructs. Fibrous collagen susceptible to SHG, however, was detected in monolayers (2D) only after stimulation with osteogenic medium. In contrast, clear and strong fiber networks appeared in cell pellets. Depending on culture media these networks differed largely in their morphology and resembled the appearance in native tissue (Fig. 1). Simultaneous SHG/AF imaging at 810nm enabled detailed imaging and 3D reconstructions of the artificial tissues (cells with surrounding collagen-I). Conclusions: MSC`s require a 3D surrounding and high initial cell density to effectively form thick and stable fibers and fiber networks. These are preferably imaged using SHG which preferably detects larger and highly assembled fibers rather than thin fibrils (Vielreicher et al. 2013. J R Soc Interface, 10(86):20130263). The differentiation state of MSC`s has a large effect on the morphology of the formed collagen networks. The collagen fibers formed in 2D cell culture are not comparably stable, putatively due to less and weaker focal adhesion contacts. Studying collagen fiber and ECM networks in general is of high interest in the engineering of artificial tissue

Fabrication and assessment of bifunctional electrospun poly(L-lactic acid) scaffolds with bioglass and zinc oxide nanoparticles for bone tissue engineering - Canales, Daniel A.; Piñones, Natalia; Saavedra, Marcela; Loyo, Carlos; Palza, Humberto; Peponi, Laura; Leonés, Adrián; Baier, Raúl Vallejos; Boccaccini, Aldo R.; Grünewald, Alina; Zapata, Paula A. (International Journal of Biological Macromolecules, 2023)
Electrospun scaffolds based on poly(L-lactic acid) (PLLA) with bioglass (n-BG) and zinc oxide (n-ZnO), and mixture of both, were developed to design bifunctional biomaterials with enhanced bioactive and biocidal properties. The presence of n-BG increased the fiber diameter of the pure PLA from 1.5 ± 0.3 μm to 3.0 ± 0.8 μm for 20 wt%. ZnO and the mixed nanoparticles did not significantly affect the morphology. The mechanical properties decreased with the presence of nanoparticles. Scaffolds based on PLA/n-BG promoted hydroxyapatite (HA) formation in simulated body fluid (SBF) that was inhibited with the presence of ZnO. Notably, mixed particles produced bioactivity although at longer times. The incorporation of n-ZnO produced a biocidal capacity against S. aureus in the polymeric scaffold, reaching a viability reduction of 60 % after 6 h of exposure. When both types of nanoparticles were combined, the bacterial viability reduction was 30 %. Pure PLA scaffolds and the composites with n-BG showed good ST-2 bone marrow-derived cell line viability, scaffolds with n-BG (pure or mixture) presented lower viability. Results validated the use of both n-BG and n-ZnO fillers for the development of novel bifunctional PLA-based scaffolds with both bioactive and biocidal properties for bone tissue engineering applications.
CRIS-Team Scopus Importer:2023-01-06
Keywords: Bioglass nanoparticle; Bone tissue engineering; Electrospun fibers; Functional scaffolds; Poly(lactic acid) based nanocomposites; Zinc oxide nanoparticle

Fabrication and characterization of Ag- and Ga-doped mesoporous glass-coated scaffolds based on natural marine sponges with improved mechanical properties - Ciraldo, Francesca; Arango-Ospina, Marcela; Goldmann, Wolfgang H.; Beltran, Ana M.; Detsch, Rainer; Gruenewald, Alina; Roether, Judith; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2020)
Natural marine sponges were used as sacrificial template for the fabrication of bioactive glass-based scaffolds. After sintering at 1050°C, the resulting samples were additionally coated with a silicate solution containing biologically active ions (Ag and Ga), well-known for their antibacterial properties. The produced scaffolds were characterized by superior mechanical properties (maximum compressive strength of 4 MPa) and total porosity of 80% in comparison to standard scaffolds made by using PU foam templates. Direct cell culture tests performed on the uncoated and coated samples showed positive results in terms of adhesion, proliferation, and differentiation of MC3T3-E1 cells. Moreover, vascular endothelial growth factor (VEGF) secretion from cells in contact with scaffold dissolution products was measured after 7 and 10 days of incubation, showing promising angiogenic results for bone tissue engineering applications. The antibacterial potential of the produced samples was assessed by performing agar diffusion tests against both Gram-positive and Gram-negative bacteria.
CRIS-Team Scopus Importer:2020-12-04
Keywords: antibacterial; bioactive glass; bone tissue engineering; ion delivery; scaffolds; VEGF

Fabrication and characterization of Ag-Sr-substituted hydroxyapatite/chitosan coatings deposited via electrophoretic deposition: A design of experiment study - Saleem, Osama; Wahaj, Muhammad; Akhtar, Muhammad Asim; Rehman, Muhammad Atiq Ur (ACS Omega, 2020)
In this study, silver-strontium-doped hydroxyapatite (AgSr-HA)/chitosan composite coatings were deposited on a 316L stainless steel (SS) substrate via electrophoretic deposition (EPD). The Taguchi design of experiment (DoE) approach was used to optimize the EPD parameters such as the applied voltage, interelectrode spacing, and deposition time. Furthermore, the concentration of AgSr-HA particles in the suspension was also optimized via the DoE approach. DoE results demonstrated that the "homogeneous"coatings were obtained at the deposition time of 7 min, deposition voltage of 20 V, and at a concentration of 5 g/L AgSr-HA particles in the suspension. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), antibacterial studies, contact angle, and roughness measurements were performed to characterize the optimized coatings. SEM images confirmed the deposition of chitosan/AgSr-HA on the SS substrate. The wettability studies indicated the hydrophilic nature of the chitosan/AgSr-HA composite coatings, which confirmed that the developed coatings are suitable for biomedical applications, e.g., orthopedics. The average surface roughness of the chitosan/AgSr-HA composite coatings was in a suitable range used to attach the bone marrow stromal cells. Chitosan/AgSr-HA composite coatings showed an effective antibacterial effect against Gram-positive and Gram-negative bacteria. Moreover, the coatings developed apatite crystals on their surface upon immersion in simulated body fluid.
CRIS-Team Scopus Importer:2020-10-16

Fabrication and characterization of bioactive and antibacterial composites for dental applications - Chatzistavrou, Xanthippi; Fenno, J. Christopher; Faulk, Denver; Badylak, Stephen; Kasuga, Toshihiro; Boccaccini, Aldo R.; Papagerakis, Petros (Acta Biomaterialia, 2014)
There is an increasing clinical need to design novel dental materials that combine regenerative and antibacterial properties. In this work the characterization of a recently developed sol-gel-derived bioactive glass ceramic containing silver ions (Ag-BG) is presented. The microstructural characteristics, ion release profile, zeta potential value and changes in weight loss and pH value as a function of the immersion time of Ag-BG in Tris buffer are evaluated. Ag-BG is also incorporated into natural extracellular matrix (ECM) hydrogel to further enhance its regenerative properties. Then, the micro and macro architectures of these new composites (ECM/Ag-BG) are characterized. In addition, the antibacterial properties of these new composites are tested against Escherichia coli and Enterococcus faecalis, a bacterium commonly implicated in the pathogenesis of dental pulp infections. Cell-material interaction is also monitored in a primary culture of dental pulp cells. Our study highlights the benefits of the successful incorporation of Ag in the bioactive glass, resulting in a stable antibacterial material with long-lasting bactericidal activity. Furthermore, this work presents for the first time the fabrication of new Ag-doped composite materials, with inductive pulp-cell proliferation and antibacterial properties (ECM/Ag-BG). This advanced composite made of Ag-BG incorporated into natural ECM possesses improved properties that may facilitate potential applications in tooth regeneration approaches. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Keywords: Antibacterial action; Bioactive glass; Composite; Natural extracellular matrix scaffold; Silver

Fabrication and Characterization of Bioactive Gelatin-Alginate-Bioactive Glass Composite Coatings on Porous Titanium Substrates - Begines, Belen; Arevalo, Cristina; Romero, Carlos; Hadzhieva, Zoya; Boccaccini, Aldo R.; Torres, Yadir (ACS Applied Materials and Interfaces, 2022)
In this research work, the fabrication of biphasic composite implants has been investigated. Porous, commercially available pure Ti (50 vol % porosity and pore distributions of 100-200, 250-355, and 355-500 μm) has been used as a cortical bone replacement, while different composites based on a polymer blend (gelatin and alginate) and bioactive glass (BG) 45S5 have been applied as a soft layer for cartilage tissues. The microstructure, degradation rates, biofunctionality, and wear behavior of the different composites were analyzed to find the best possible coating. Experiments demonstrated the best micromechanical balance for the substrate containing 200-355 μm size range distribution. In addition, although the coating prepared from alginate presented a lower mass loss, the composite containing 50% alginate and 50% gelatin showed a higher elastic recovery, which entails that this type of coating could replicate the functions of the soft tissue in areas of the joints. Therefore, results revealed that the combinations of porous commercially pure Ti and composites prepared from alginate/gelatin/45S5 BG are candidates for the fabrication of biphasic implants not only for the treatment of osteochondral defects but also potentially for any other diseases affecting simultaneously hard and soft tissues.
CRIS-Team Scopus Importer:2022-04-15
Keywords: bioactive coating; biopolymer composites; osteochondral defects; porous titanium; tribomechanical behavior

Fabrication and characterization of biodegradable poly(3-hydroxybutyrate) composite containing bioglass - Boccaccini, Aldo R.; et al. (Biomacromolecules, 2007)
Bacterially derived poly(3-hydroxybutyrate) (P(3HB)) has been used to produce composite films by incorporating Bioglass particles (<5 μm) in 5 and 20 wt % concentrations. P(3HB) was produced using a large scale fermentation technique. The polymer was extracted using the Soxhlet technique and was found to have similar thermal and structural properties to the commercially available P(3HB). The effects of adding Bioglass on the microstructure surface and thermal and mechanical properties were examined using differential scanning calorimetry, dynamic mechanical analysis (DMA), X-ray diffraction, surface interferometry, electron microscopy, and nanoindentation. The addition of increasing concentrations of Bioglass in the polymer matrix reduced the degree of crystallinity of the polymer as well as caused an increase in the glass transition temperature as determined by DMA. The presence of Bioglass particulates reduced the Young's modulus of the composite. The storage modulus and the loss modulus, however, increased with the addition of 20 wt % Bioglass. A short period (28 days) in vitro bioactivity study in simulated body fluid confirmed the bioactivity of the composites, demonstrated by the formation of hydroxyapatite crystals on the composites surface. © 2007 American Chemical Society.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.fabric

Fabrication and characterization of cinnamaldehyde-loaded mesoporous bioactive glass nanoparticles/phbv-based microspheres for preventing bacterial infection and promoting bone tissue regeneration - Chotchindakun, Kittipat; Pekkoh, Jeeraporn; Ruangsuriya, Jetsada; Zheng, Kai; Ünalan, Irem; Boccaccini, Aldo R. (Polymers, 2021)
Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is considered a suitable polymer for drug delivery systems and bone tissue engineering due to its biocompatibility and biodegradability. However, the lack of bioactivity and antibacterial activity hinders its biomedical applications. In this study, mesoporous bioactive glass nanoparticles (MBGN) were incorporated into PHBV to enhance its bioactivity, while cinnamaldehyde (CIN) was loaded in MBGN to introduce antimicro-bial activity. The blank (PHBV/MBGN) and the CIN-loaded microspheres (PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20) were fabricated by emulsion solvent extrac-tion/evaporation method. The average particle size and zeta potential of all samples were in-vestigated, as well as the morphology of all samples evaluated by scanning electron microscopy. PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20 significantly exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli in the first 3 h, while CIN releasing behavior was observed up to 7 d. Human osteosarcoma cell (MG-63) proliferation and attachment were noticed after 24 h cell culture, demonstrating no adverse effects due to the presence of microspheres. Additionally, the rapid formation of hydroxyapatite on the composite microspheres after immersion in simulated body fluid (SBF) during 7 d revealed the bioactivity of the composite mi-crospheres. Our findings indicate that this system represents an alternative model for an antibacterial biomaterial for potential applications in bone tissue engineering.
CRIS-Team Scopus Importer:2021-06-25
Keywords: Antibacterial activity; Bioactive glass nanoparticles; Bone tissue engineering; Cinnamon oil; Drug delivery systems; Emulsion solvent evaporation method; Polyhydroxyalkanoates

Fabrication and characterization of copper(II)-chitosan complexes as antibiotic-free antibacterial biomaterial - Gritsch, Lukas; Lovell, Christopher; Goldmann, Wolfgang; Boccaccini, Aldo R. (Carbohydrate Polymers, 2018)
<span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif; font-size: medium;">We produced and characterized copper(II)-chitosan complexes fabricated via in-situ precipitation as antibiotic-free antibacterial biomaterials. Copper was bound to chitosan from a dilute acetic acid solution of chitosan and copper(II) chloride exploiting the ability of the polysaccharide to chelate metal ions. The influence of copper(II) ions on the morphology, structure and hydrophobicity of the complexes was evaluated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy and static contact-angle measurements. To assess the biological response to the materials, cell viability and antibacterial assays were performed using mouse embryonic fibroblasts and both Gram-positive and −negative bacteria. Combined analysis of cell and bacterial studies identified a threshold concentration at which the material shows outstanding antibacterial properties without significantly affecting fibroblast viability. This key outcome sets copper(II)- chitosan as a promising biomaterial and encourages further investigation on similar systems toward the development of new antibiotic-free antibacterial technologies.
Keywords: ChitosanCopperChelationTherapeutic ionsAntimicrobial materialsAntibiotic-free

Fabrication and characterization of electrophoretically deposited chitosan-hydroxyapatite composite coatings on anodic titanium dioxide layers - Pawlik, Anna; Ur Rehman, Muhammad Atiq; Nawaz, Qaisar; Bastan, Fatih Erdem; Sulka, Grzegorz D.; Boccaccini, Aldo R. (Electrochimica Acta, 2019)
Anodic nanoporous titanium dioxide (ATO) layers were synthesized via a three-step anodization process in a solution based on ethylene glycol containing fluoride ions and water. The as-prepared samples were annealed at 400 degrees C in order to transform amorphous oxide into the anatase phase. The anatase samples were coated with a chitosan-hydroxyapatite composite by using electrophoretic deposition (EPD) technique. A design of experiments (DoE) approach with Taguchi methodology was used in order to optimize the EPD parameters (voltage, time, and concentration of hydroxyapatite). A model describing the relationship between the mass of chitosan-hydroxyapatite composite coating and EPD parameters was proposed. The suggested model allows to estimate the mass (yield) of the coating based on the applied voltage, deposition time, and concentration of hydroxyapatite. It was shown that the concentration of hydroxyapatite in the suspension has the most significant impact on the morphology of the deposited coating. The coatings were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), contact angle and surface roughness measurements. The presence of chitosan-hydroxyapatite composite coatings increased the surface roughness of coated samples compared to the bare ATO layers. The morphology, compositional analysis, and crystalline phases of the EPD coatings confirmed that the anodic TiO2 samples were successfully coated with a chitosan-hydroxyapatite composite to achieve a more suitable bone-contacting surface. (C) 2019 Elsevier Ltd. All rights reserved.
CRIS-Team WoS Importer:2019-05-03

Fabrication and characterization of electrospun poly-DL-lactide (PDLLA) fibrous coatings on 45S5 Bioglass® substrates for bone tissue engineering applications - Yunos, D. M.; Ahmad, Z.; Boccaccini, Aldo R. (Journal of Chemical Technology and Biotechnology, 2010)
BACKGROUND: This work focuses on combining electrospun biodegradable poly-DL-lactide (PDLLA) fibres and 45S5 Bioglass® for tissue engineering applications. RESULTS: A variety of fibrous structures were produced upon application of an electric field to a flowing solution of PDLLA (5 wt/v%) in di-methyl carbonate (DMC). Electrospinning was achieved at an applied voltage of 8.5 kV for a fixed flow rate of 5 μ Lmin-1. Scanning electron microscopy images of PDLLA fibres deposited on 45S5 Bioglass® sintered pellets revealed that the fibres had diameters in the range 100-200 nm, leading to increased surface roughness, as assessed by white light interferometry. Bioactivity studies on PDLLA fibre coated Bioglass® substrates were carried out in simulated body fluid (SBF) for 7, 14 and 28 days. It was found that mineralization of PDLLA fibres on 45S5 Bioglass® substrate (formation of hydroxyapatite) occurred after 7 days of immersion in SBF and full coverage of PDLLA fibres with HA nanocrystals was achieved after 14 days in SBF. CONCLUSION: The approach investigated represents a convenient method to develop a controlled mineralized fibrous topography on bioactive glass substrates for improved cell attachment, which can be exploited in bone tissue engineering applications. ©2009 Society of Chemical Industry.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.fabric_8
Keywords: Bioactive glass substrates; Bioactivity studies; Electrospinning; Light interferometry; PDLLA fibres; SBF; Tissue engineering

Fabrication and characterization of multifunctional, asymmetric bilayer films based on chitosan/gelatin/mesoporous bioactive glass nanoparticles for guided bone regeneration - Akhtar, Muhammad Asim; Novak, Jan; Radwansky, Christian; Boccaccini, Aldo R. (Journal of Materials Research, 2024)
Two-faced GBR membranes were fabricated by electrophoretic deposition (EPD) using a combination of biopolymers and mesoporous bioactive glass nanoparticles (MBGNs). The membrane design was aimed at leveraging the advantageous properties of both biopolymers and MBGNs. The dense composite layer consisted of chitosan (CS) incorporating MBGNs and it was functionalized with a phytotherapeutic drug, naringin (Nar). The porous layer consisted of CS-gelatin (Gel)- MBGNs as well as copper chelated chitosan (Cu(II)-CS)-Gel-MBGNs composites. EPD was conducted in direct current mode. The antibacterial activity of the membranes as a result of the presence of Cu(II) and Nar was confirmed. The films were cytocompatible when tested with MC3T3-E1 (pre-osteoblastic) and MG-63 (osteoblast like) cell lines. However, a slight cytotoxic effect of the releasing Cu(II) ions was determined. In contrast, Nar-loaded films revealed improved cell viability. The results indicate the high potential of EPD to fabricate bilayer structures for GBR applications. Graphical abstract: (Figure presented.).
CRIS-Team Scopus Importer:2024-09-06
Keywords: Bioactive glass nanoparticles; Chitosan; Electrophoretic deposition; Guided bone regeneration; Naringin

Fabrication and characterization of porous bioceramic composites based on hydroxyapatite and titania - Boccaccini, Aldo R.; et al. (Materials Chemistry and Physics, 2007)
Porous bioinert-bioactive composite ceramics were fabricated from hydroxyapatite and titania powder mixtures by using several techniques including involving the use of porogens such as carbon fibers, polyurethane (PU) foams or H2O2. The optimal titania content in the composite was 15 wt.%. Using H2O2 as pore creator, a porosity of 65 ± 4% was achieved. The pores were shown to be interconnected with dimensions in the range 100-1000 μm. Young's modulus, bending strength and compressive strength of the porous composite were: 1.7 ± 0.2 GPa, 2.1 ± 0.3 MPa and 7 ± 1 MPa, respectively. This porous material can find applications as scaffold in bone tissue regeneration strategies. © 2007 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.fabric_2
Keywords: Bioceramics; Ceramic composites; Hydroxyapatite; Porosity; Sintering; Titania

Fabrication and characterization of zein/bioactive glass deposited on pretreated magnesium via electrophoretic deposition - Ahmed, Yusra; Nawaz, Aneeqa; Virk, Ranjot; Wadood, Abdul; Ur Rehman, Muhammad Atiq (International Journal of Ceramic Engineering & Science, 2020)
In this study, zein/45S5 bioactive glass (BG) coatings were deposited via electrophoretic deposition (EPD) on pretreated pure magnesium (Mg) substrates to control the rapid degradation of magnesium and to improve the bioactive properties of Mg implants. The EPD parameters were first optimized on stainless steel (SS), and then, the optimum EPD parameters were applied to obtain zein/BG composite coatings on Mg substrates. The kinetics of the EPD process was studied by plotting the graph between current density and deposition time at fixed applied voltage. The morphology and chemical composition (qualitatively) of the obtained coatings were studied by scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FTIR), respectively. SEM and FTIR results showed that both zein and BG were successfully deposited, and a homogeneous film of zein/BG was formed on the surface of the substrate. The contact angle measurements confirmed that the zein/BG coatings are suitable for the initial protein attachment.
CRIS-Team Scopus Importer:2024-12-16
Keywords: bioactivity glass; electrophoretic deposition; Magnesium; Zein

Fabrication and characterization of zein–bioactive glass scaffolds - Naseri, Shiva; Hum, Jasmin; Lepry, William Cole; Miri, Amir Kamal; Nazhat, Showan Najdat; Boccaccini, Aldo R. (Bioinspired, Biomimetic and Nanobiomaterials, 2015)
Plant proteins show advantages over animal-based proteins for biomaterial applications attributable to their ease of availability and suitable biodegradability. In this study, composite foams based on zein and 45S5 bioactive glass (BG) particles were produced through salt leaching for potential applications in bone tissue engineering (BTE) applications. Different characterization techniques were used including scanning electron microscopy for morphological and microstructural analysis, ATR-FTIR spectroscopy and X-ray diffraction for composition characterization and mechanical tests. Zein–BG composite scaffolds demonstrate enhanced bioactivity with a compressive modulus and strength around 5·7 MPa and 1·9 MPa, respectively. Zein–BG composite scaffolds constitute a new bioactive material with potential applications in BTE.
Keywords: Bioactive glass; Bioactivity; Composite materials; Scaffolds; Zein

Fabrication and cytotoxicity assessment of novel polysiloxane/bioactive glass films for biomedical applications - Francis, Adel; Detsch, Rainer; Boccaccini, Aldo R. (Ceramics International, 2016)
Keywords: Bioactive glasses; Composite coatings; Cytotoxicity; FTIR; Polymer-derived ceramics; Polysiloxane; Silicon oxycarbide; Silicones

Fabrication of alginate-gelatin crosslinked hydrogel microcapsules and evaluation of the microstructure and physico-chemical properties - Sarker, Bapi; Papageorgiou, Dimitrios G.; Silva, Raquel; Zehnder, Tobias; Gul-E-Noor, Farhana; Bertmer, Marko; Kaschta, Joachim; Chrissafis, Konstantinos; Detsch, Rainer; Boccaccini, Aldo R. (Journal of Materials Chemistry B, 2014)
Microencapsulation of cells by using biodegradable hydrogels offers numerous attractive features for a variety of biomedical applications including tissue engineering. This study highlights the fabrication of microcapsules from an alginate-gelatin crosslinked hydrogel (ADA-GEL) and presents the evaluation of the physico-chemical properties of the new microcapsules which are relevant for designing suitable microcapsules for tissue engineering. Alginate di-aldehyde (ADA) was synthesized by periodate oxidation of alginate which facilitates crosslinking with gelatin through Schiff's base formation between the free amino groups of gelatin and the available aldehyde groups of ADA. Formation of Schiff's base in ADA-GEL and aldehyde groups in ADA was confirmed by FTIR and NMR spectroscopy, respectively. Thermal degradation behavior of films and microcapsules fabricated from alginate, ADA and ADA-GEL was dependent on the hydrogel composition. The gelation time of ADA-GEL was found to decrease with increasing gelatin content. The swelling ratio of ADA-GEL microcapsules of all compositions was significantly decreased, whereas the degradability was found to increase with the increase of gelatin ratio. The surface morphology of the ADA-GEL microcapsules was totally different from that of alginate and ADA microcapsules, observed by SEM. Two different buffer solutions (with and without calcium salt) have an influence on the stability of microcapsules which had a significant effect on the gelatin release profile of ADA-GEL microcapsules in these two buffer solutions. © 2014 The Royal Society of Chemistry.

Fabrication of Biocompatible Electrospun Poly(epsilon-caprolactone)/Gelatin Nanofibers Loaded with Pinus radiata Bark Extracts for Wound Healing Applications - Borges-Vilches, Jessica; Ünalan, Irem; Fernandez, Katherina; Boccaccini, Aldo R. (Polymers, 2022)
In this study, poly(epsilon-caprolactone) (PCL)/gelatin (GEL) electrospun nanofibers loaded with two different concentrations of Pinus radiata bark extracts (PEs) were fabricated via electrospinning for wound healing applications. The effects of incorporating PE into PCL/GEL electrospun nanofibers were investigated regarding their physicochemical properties and in vitro biocompatibility. All electrospun nanofibers showed smooth, uniform, and bead-free surfaces. Their functional groups were detected by ATR-FTIR spectroscopy, and their total phenol content was measured by a Folin-Ciocalteu assay. With PE addition, the electrospun nanofibers exhibited an increase in their wettability and degradation rates over time and a decrease in their tensile stress values from 20 +/- 4 to 8 +/- 2 MPa for PCL/GEL and PCL/GEL/0.36%PE samples, respectively. PE was also released from the fibrous mats in a rather controlled fashion. The PCL/GEL/0.18%PE and PCL/GEL/0.36%PE electrospun nanofibers inhibited bacterial activity at around 6 +/- 0.1% and 23 +/- 0.3% against E. coli and 14 +/- 0.1% and 18 +/- 0.2% against S. aureus after 24 h incubation, respectively. In vitro cell studies showed that PE-loaded electrospun nanofibers enhanced HaCaT cell growth, attachment, and proliferation, favoring cell migration towards the scratch area in the wound healing assay and allowing a complete wound closure after 72 h treatment. These findings suggested that PE-loaded electrospun nanofibers are promising materials for antibiotic-free dressings for wound healing applications.
CRIS-Team WoS Importer:2022-07-08

Fabrication of cell-loaded two-phase 3D constructs for tissue engineering - Zehnder, Tobias; Freund, Tim; Demir, Merve; Detsch, Rainer; Boccaccini, Aldo R. (Materials, 2016)
Keywords: Alginate dialdehyde; Biofabrication; Gelatine; Hydrogels; Polycaprolactone; Sequential bioplotting; Tissue engineering

Fabrication of CNT-SiC/SiC composites by electrophoretic deposition - König, Katja; Novak, Sasa; Ivekovic, Aljaz; Rade, Katja; Meng, Decheng; Boccaccini, Aldo R.; Kobe, Spomenka (Journal of the European Ceramic Society, 2010)
Due to the outstanding mechanical and thermal properties of carbon nanotubes (CNTs), they are considered suitable reinforcement for structural materials. In this study, for the first time, electrophoretic deposition (EPD) was used to deposit (multi-walled) CNTs onto SiC fibres (SiCf) to form an effective CNT interphase layer for SiCf/SiC composites. This deposition was followed by electrophoretic infiltration of the CNT-coated SiC fibre mats with SiC powder to fabricate a new CNT-SiC-fibre-reinforced SiC-matrix (SiCf/SiC) composite for fusion applications. In these EPD experiments, a commercial aqueous suspension of negatively charged CNTs and an optimized aqueous suspension of negatively charged SiC particles were used. The CNT-coatings on the SiC fibres were firm and homogenous, and uniformly distributed nanotubes were observed on the fibre surfaces. In a following step of EPD, a thick SiC layer was formed on the fibre mat when the CNT-coated SiC fibres were in contact with the positive electrode of the EPD cell; however, spaces between the fibres were not fully filled with SiC. Conversely, when CNT-coated SiC fibres were isolated from the electrode, the SiC particles were able to gradually fill the fibre mat resulting in relatively high infiltration, which leads to dense composites. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.fabric
Keywords: Carbon nanotubes (CNTs); Coatings; Electrophoretic deposition; Interphase; SiC

Fabrication of electrospun poly (3-hydroxybutyrate)/poly (ε-caprolactone)/silica hybrid fibermats with and without calcium addition - Ding, Yaping; Roether, Judith; Boccaccini, Aldo R.; Schubert, Dirk W. (European Polymer Journal, 2014)
Poly (3-hydroxybutyrate)(PHB)/poly (ε-caprolactone)(PCL)/silica hybrid scaffolds with and without calcium were fabricated through the combination of electrospinning and sol-gel methods. In this paper, the effects of different amounts of silica sol on the morphology, mechanical and thermal properties of hybrid scaffolds were studied. The results indicated that as the silica content increased to 50 wt%, the ultimate tensile strength and modulus were enhanced to 191% and 614%, respectively. In addition, the presence of silica decreased the elongation at break significantly. Calcium addition changed the morphology of the hybrid scaffolds from relatively dense fibermats to highly fluffy porous structures, which may be due to the ionization of Ca in the polymer solution. Chemical interactions between the different components and the thermal properties were also based on FTIR, DSC and TGA measurements. The addition of inorganic components significantly decreased the crystallinity of PHB and PCL, which was also confirmed by XRD analysis. Due to the intrinsic performance of the biopolymer and inorganic components, the scaffolds in the present study have great potential for tissue engineering applications. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Electrospinning; Hybrid scaffolds; Poly (3-hydroxybutyrate); Poly (ε-caprolactone); Sol-gel

Fabrication of functional zirconia surfaces using a two-beam interference setup employing a picosecond laser system with 532-nm wavelength: Morphology, microstructure, and wettability - Henriques, Bruno; Fabris, Douglas; Voisiat, Bogdan; Boccaccini, Aldo R.; Lasagni, Andrés Fabián (Journal of the American Ceramic Society, 2023)
The aim of this work was to evaluate the feasibility of the fabrication of microtextures in zirconia using the direct laser interference patterning (DLIP) technique. A green ultra-short pulsed laser (532 nm, 10 ps) with a two-beam interference setup was used to produce line-like structures with a spatial period of 3 µm. For a fixed set of fluence and pulse-to-pulse overlap values (6.2 J/cm2, 81%), periodic structures were successfully created for different hatch distances. The average depth of the features ranged from 0.37 µm for a hatch distance of 14.4 µm up to 0.84 µm for a hatch distance of 12.4 µm. However, a further decrease in hatch distance did not result in an increase in depth since the region of the ridges is also ablated. Scanning electron microscopy analysis showed pores formation on the laser grooves, but no sign of micro-cracking could be observed. Wettability tests showed an increase in hydrophobicity after DLIP. These results bring exciting perspectives on the fabrication of micro-textures with DLIP on zirconia surface.
CRIS-Team Scopus Importer:2023-08-18
Keywords: direct laser interference patterning; surface structuring; ultra-short pulsed laser; zirconia

Fabrication of Gelatin Methacrylate (GelMA) Scaffolds with Nano- and Micro-Topographical and Morphological Features. - Aldana, Ana Agustina; Malatto, Laura; Ur Rehman, Muhammad Atiq; Boccaccini, Aldo R.; Abraham, Gustavo Abel (Nanomaterials, 2019)
The design of biomimetic biomaterials for cell culture has become a great tool to study and understand cell behavior, tissue degradation, and lesion. Topographical and morphological features play an important role in modulating cell behavior. In this study, a dual methodology was evaluated to generate novel gelatin methacrylate (GelMA)-based scaffolds with nano and micro topographical and morphological features. First, electrospinning parameters and crosslinking processes were optimized to obtain electrospun nanofibrous scaffolds. GelMA mats were characterized by SEM, FTIR, DSC, TGA, contact angle, and water uptake. Various nanofibrous GelMA mats with defect-free fibers and stability in aqueous media were obtained. Then, micropatterned molds produced by photolithography were used as collectors in the electrospinning process. Thus, biocompatible GelMA nanofibrous scaffolds with micro-patterns that mimic extracellular matrix were obtained successfully by combining two micro/nanofabrication techniques, electrospinning, and micromolding. Taking into account the cell viability results, the methodology used in this study could be considered a valuable tool to develop patterned GelMA based nanofibrous scaffolds for cell culture and tissue engineering.

Fabrication of gold-nanoshell/polycaprolactonecomposite films with high electrical conductivity - Naseri, Shiva; Diba, Mani; Golkar, Saeedeh; Boccaccini, Aldo R.; Klupp Taylor, Robin (Materials Letters, 2014)
Gold nanoshells on 1.1 μm diameter silica cores were produced via a seeded growth approach and their quality evaluated using optical measurements. The particles were combined with polycaprolactone to produce a flexible biocompatible composite film with high conductivity (1.51 S cm-1) and relatively low effective gold loading (16.86 wt%) in comparison with other reports in the literature. The morphology of the composite was shown to comprise nanoshell-filled pores percolating a polymer-rich matrix. The obtained films have potential for biomedical applications such as in patches for cardiac tissue engineering, combining biocompatibility, flexibility and electrical conductivity. © 2014 Elsevier B.V.
Keywords: Conductivity; Metal nanoshells; Nanocomposite; Plasmon resonance; Polycaprolactone

Fabrication of Hydrogel-Based Composite Fibers and Computer Simulation of the Filler Dynamics in the Composite Flow - Gruhn, Thomas; Monsalve, Camilo Ortiz; Müller, Claudia; Heid, Susanne; Boccaccini, Aldo R.; Salehi, Sahar (Bioengineering, 2023)
Fibrous structures with anisotropic fillers as composites have found increasing interest in the field of biofabrication since they can mimic the extracellular matrix of anisotropic tissues such as skeletal muscle or nerve tissue. In the present work, the inclusion of anisotropic fillers in hydrogel-based filaments with an interpenetrating polymeric network (IPN) was evaluated and the dynamics of such fillers in the composite flow were analyzed using computational simulations. In the experimental part, microfabricated rods (200 and 400 μm length, 50 μm width) were used as anisotropic fillers in extrusion of composite filaments using two techniques of wet spinning and 3D printing. Hydrogels such as oxidized alginate (ADA) and methacrylated gelatin (GelMA) were used as matrices. In the computational simulation, a combination of computational fluid dynamics and coarse-grained molecular dynamics was used to study the dynamics of rod-like fillers in the flow field of a syringe. It showed that, during the extrusion process, microrods are far from being well aligned. Instead, many of them tumble on their way through the needle leading to a random orientation in the fiber which was confirmed experimentally.
CRIS-Team Scopus Importer:2023-05-12
Keywords: anisotropy; composite filaments; computational simulation; microrods; wet spinning

Fabrication of nanoparticulate inks for applications in printable electronics - Reindl, Armin; Aldabergenova, Saule; Altin, Ergün; Frank, Gerhard; Peukert, Wolfgang (4, 2007)
Semiconducting nanoparticles were dispersed systematically in organic solvents using a variety of methods. In the case of silicon particles prepared by gas phase synthesis a high specific energy input is necessary to obtain intrinsically stable suspensions. Therefore Si nanoparticles were dispersed for 24 hours in 1-butanol using a stirred media mill. Via this process intrinsically stable suspensions of Si nanoparticles were produced. The evolution of morphology, particle size and structure was investigated by dynamic light scattering, X-ray diffraction, Raman spectroscopy, and high resolution transmission electron microscopy as a function of dispersing time. The microstructural development with varying crystallite size and crystalline volume fraction was analyzed by Raman spectroscopy and directly confirmed by transmission electron microscopy measurements. The surface chemistry of the Si nanoparticles was analyzed by diffuse reflectance infrared Fourier transform spectroscop
Keywords: Raman spectroscopy; HRTEM; Stirred media mill; Silicon nanoparticles; XRD

Fabrication of Quasi-2D Shape-Tailored Microparticles using Wettability Contrast-Based Platforms - Neto, Mafalda D.; Stoppa, Aukha; Neto, Miguel A.; Oliveira, Filipe J.; Gomes, Maria C.; Boccaccini, Aldo R.; Levkin, Pavel A.; Oliveira, Mariana B.; Mano, Joao F. (Advanced Materials, 2021)
The ability to fabricate materials with ultrathin architectures enables the breakthrough of low-dimensional structures with high surface area that showcase distinctive properties from their bulk counterparts. They are exploited in a wide range of fields, including energy harvesting, catalysis, and biomedicine. Despite such versatility, the fine tuning of the lateral dimensions and geometry of these structures remains challenging. Prepatterned platforms gain significant attention as enabling technologies to process materials with highly controlled shapes and dimensions. Herein, different nanometer-thick particles of various lateral sizes and geometries (e.g., squares, circles, triangles, hexagons) are processed with high precision and definition, taking advantage of the wettability contrast of oleophilic-oleophobic patterned surfaces. Quasi-2D polymeric microparticles with high shape- and size-fidelity can be retrieved as freestanding objects in a single step. These structures show cell-mediated pliability, and their integration in gravity-enforced human adipose-derived stem cell spheroids leads to an enhanced metabolic activity and a modulated secretion of proangiogenic factors.
CRIS-Team WoS Importer:2021-03-12

Facile preparation of multifunctional superparamagnetic PHBV microspheres containing SPIONs for biomedical applications - Li, Wei; Zaloga, Jan; Ding, Yaping; Liu, Yufang; Janko, Christina; Pischetsrieder, Monika; Alexiou, Christoph; Boccaccini, Aldo R. (Scientific Reports, 2016)
The promising potential of magnetic polymer microspheres in various biomedical applications has been frequently reported. However, the surface hydrophilicity of superparamagnetic iron oxide nanoparticles (SPIONs) usually leads to poor or even failed encapsulation of SPIONs in hydrophobic polymer microspheres using the emulsion method. In this study, the stability of SPIONs in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) solution was significantly increased after surface modification with lauric acid. As a result, magnetic PHBV microspheres with high encapsulation efficiencies (71.0-87.4%) were prepared using emulsion-solvent extraction/evaporation method. Magnetic resonance imaging (MRI) showed significant contrast for the magnetic PHBV microspheres. The toxicity of these magnetic PHBV microspheres towards human T-lymphoma suspension cells and adherent colon carcinoma HT-29 cells was investigated using flow cytometry, and they were shown to be non-toxic in a broad concentration range. A model drug, tetracycline hydrochloride, was used to demonstrate the drug delivery capability and to investigate the drug release behavior of the magnetic PHBV microspheres. The drug was successfully loaded into the microspheres using lauric acid-coated SPIONs as drug carrier, and was released from the microspheres in a diffusion controlled manner. The developed magnetic PHBV microspheres are promising candidates for biomedical applications such as targeted drug delivery and MRI.

Facile preparative access to bioactive silicon oxycarbides with tunable porosity - Xie, Fangtong; Ionescu, Emanuel; Arango Ospina, Marcela; Riedel, Ralf; Boccaccini, Aldo R.; Gonzalo-Juan, Isabel (Materials, 2019)
In the present work, Ca-containing silicon oxycarbides (SiCaOC) with varying Ca content have been synthesized via sol-gel processing and thermal treatment in inert gas atmosphere (pyrolysis). It has been shown that the as-prepared SiCaOC materials with low Ca loadings (Ca/Si molar ratios = 0.05 or 0.12) were X-ray amorphous; their glassy network contains Q3 sites, indicating the presence of Ca2+ at non-bridging-oxygen sites. SiCaOC with high Ca content (i.e., Ca/Si molar ratio = 0.50) exhibits the presence of crystalline calcium silicate (mainly pseudowollastonite). Furthermore, it has been shown that the incorporation of Ca into the SiOC glassy network has a significant effect on its porosity and specific surface area. Thus, the as-prepared Ca-free SiOC material is shown to be non-porous and having a specific surface area (SSA) of 22.5 m2/g; whereas SiCaOC with Ca/Si molar ratio of 0.05 exhibits mesoporosity and a SSA value of 123.4 m2/g. The further increase of Ca content leads to a decrease of the SSA and the generation of macroporosity in SiCaOC; thus, SiCaOC with Ca/Si molar ratio of 0.12 is macroporous and exhibits a SSA value of 39.5 m2/g. Bioactivity assessment in simulated body fluid (SBF) confirms the hydroxyapatite formation on all SiCaOC samples after seven days soaking, unlike the relatively inert ternary silicon oxycarbide reference. In particular, SiCaOC with a Ca/Si molar ratio of 0.05 shows an increased apatite forming ability compared to that of SiCaOC with Ca/Si molar ratio of 0.12; this difference is considered to be a direct consequence of the significantly higher SSA of the sample with the Ca/Si ratio of 0.05. The present work indicates two effects of Ca incorporation into the silicon oxycarbide glassy network on its bioactivity: Firstly, Ca2+ is shown to contribute to the slight depolymerization of the network, which clearly triggers the hydroxyapatite formation (compare the bioactive behavior of SiOC to that of SiCaOC with Ca/Si molar ratio 0.12 upon SBF exposure); secondly, the Ca2+ incorporation seems to strongly affect the porosity and SSA in the prepared SiCaOC materials. There is an optimum of Ca loading into the silicon oxycarbide glassy network (at a Ca/Si molar ration of 0.05), which provides mesoporosity and reaches maximum SSA, both highly beneficial for the bioactive behavior of the materials. An increase of the Ca loading leads, in addition to the crystallization of calcium silicates, to a coarsening of the pores (i.e., macroporosity) and a significant decrease of the SSA, both negatively affecting the bioactivity.
CRIS-Team Scopus Importer:2019-12-10
Keywords: Apatite forming ability; Bioactivity; Mesoporosity; Silicon oxycarbide; Sol-gel; Specific surface area

Facile production of porous bioactive glass scaffolds by the foam replica technique combined with sol-gel/electrophoretic deposition - Cabanas Polo, Sandra; Philippart, Anahi; Boccardi, Elena; Hazur, J.; Boccaccini, Aldo R. (Ceramics International, 2016)
Keywords: Bioactive glass; Electrophoretic deposition; Foam replication technique; Scaffolds; Sol-gel

Facile Synthesis of Gallium (III)-Chitosan Complexes as Antibacterial Biomaterial - Akhtar, Muhammad Asim; Hadzhieva, Zoya; Ilyas, Kanwal; Ali, Muhammad Saad; Peukert, Wolfgang; Boccaccini, Aldo R. (Pharmaceutics, 2021)
Even though antibiotic treatment remains one of the most common tools to handle bacterial infections, the excessive antibiotic concentration at the target site may lead to undesired effects. Aiming at the fabrication of antibiotic-free biomaterials for antibacterial applications, in this work, we propose the synthesis of gallium (III)-chitosan (Ga (III)-CS) complexes with six different gallium concentrations via an in situ precipitation method. Fourier Transform infrared spectroscopy indicated the chelation of chitosan with Ga (III) by peak shifts and changes in the relative absorbance of key spectral bands, while energy-dispersive X-ray spectroscopy indicated the homogenous distribution of the metal ions within the polymer matrix. Additionally, similar to CS, all Ga (III)-CS complexes showed hydrophobic behavior during static contact-angle measurements. The antibacterial property of the complexes against both Gram-negative and Gram-positive bacteria was positively correlated with the Ga (III) concentration. Moreover, cell studies confirmed the nontoxic behavior of the complexes against the human osteosarcoma cell line (MG-63 cells) and mouse embryonic fibroblasts cell line (MEFs). Based on the results of this study, new antibiotic-free antibacterial biomaterials based on Ga (III)-CS can be developed, expanding the scope of CS applications in the biomedical field.

False banana fiber reinforced geopolymer composite – A novel sustainable material - Addis, Lulseged Belay; Sendekie, Zenamarkos Bantie; Habtu, Nigus Gabbiye; Schubert, Dirk W.; Roether, Judith; Boccaccini, Aldo R. (Ceramics International, 2024)
A new geopolymer composite material was produced using low-calcium fly ash and false banana plant fiber. The effect of fiber content and length on the mechanical and microstructural properties of the resulting composite material was investigated. Results showed that the addition of alkali-treated false banana fiber significantly improved the compressive and splitting tensile strength of the composites. In particular, incorporating a 10 mm length fiber at a 1.4 % volume fraction increased compressive and splitting tensile strength by 31 % and 33 %, respectively, when compared to the pure geopolymer paste specimens. Furthermore, unlike the neat geopolymer paste specimens, all composites failed gracefully. In addition to this, FTIR absorption peaks and SEM micrographs demonstrated that alkali treatment effectively changes fiber morphology and chemical characteristics. Additionally, fiber pull-out, fiber bridging, and fiber fracture were identified as energy-absorbing mechanisms responsible for increasing the mechanical properties of the composites. In general, the results showed that using natural false banana fiber as reinforcement enhances the mechanical properties of geopolymer composites, making them a more environmentally friendly alternative to synthetic fibers in composite production.
CRIS-Team Scopus Importer:2024-05-10
Keywords: Alkali treatment; False banana fiber; Geopolymer composites; Mechanical properties; Microstructure

Favorable angiogenic properties of the borosilicate bioactive glass 0106-B1 result in enhanced: In vivo osteoid formation compared to 45S5 Bioglass - Westhauser, F.; Widholz, B.; Nawaz, Qaisar; Tsitlakidis, S.; Hagmann, S.; Moghaddam, A.; Boccaccini, Aldo R. (Biomaterials Science, 2019)
The 45S5-bioactive glass (BG) composition is the most commonly investigated amongst BG-based bone substitutes. By changing BG compositions and by addition of therapeutically active ions such as boron, the biological features of BGs can be tailored towards specific needs and possible drawbacks can be overcome. The borosilicate glass 0106-B1 (composition in wt%: 37.5 SiO2, 22.6 CaO, 5.9 Na2O, 4.0 P2O5, 12.0 K2O, 5.5 MgO, 12.5 B2O3) has demonstrated pro-angiogenic properties. However, the osteogenic performance of the 0106-B1-BG and its influence on cell viability and proliferation in vitro as well as its osteogenic and angiogenic properties in vivo have not been investigated. Therefore, in this study, the impact of 0106-B1-BG and 45S5-BG on osteogenic differentiation, viability and proliferation on human mesenchymal stromal cells (MSCs) was assessed in vitro. Furthermore, MSC-seeded scaffolds made from both BG types were implanted subcutaneously in immunodeficient mice for 10 weeks. Osteoid formation was quantified by histomorphometry, vascularization was visualized by immunohistological staining. Additionally, the in vivo expression patterns of genes correlating with osteogenesis and angiogenesis were analyzed. In vitro, the impact of 45S5-BG and 0106-B1-BG on the proliferation, viability and osteogenic differentiation of MSCs was comparable. In vivo, scaffolds made from 0106-B1-BG significantly outperformed the 45S5-BG-based scaffolds regarding the amount and maturation of the osteoid. Furthermore, 0106-B1-BG-based scaffolds showed significantly increased angiogenic gene expression patterns. In conclusion, the beneficial angiogenic properties of 0106-B1-BG result in improved osteogenic properties in vivo, making the 0106-B1-BG a promising candidate for further investigation, e.g. in a bone defect model.
CRIS-Team Scopus Importer:2019-11-29

Feasibility Study of Bioactive Hydrogel Coatings on Ti-6Al-4V Gyroid Scaffolds for Bone Tissue Engineering - Schöbel, Lisa; Ayerbe, Maddi Garcia; Polley, Christian; Arruebarrena, Gurutze; Seitz, Hermann; Boccaccini, Aldo R. (ACS Biomaterials Science and Engineering, 2025)
Titanium alloys are commonly used for bone replacement due to their excellent corrosion resistance. However, they can cause stress shielding due to their high stiffness. Consequently, porous titanium scaffolds can be designed to reduce the elastic mismatch with bone, and further hydrogel coatings can be applied to mimic the extracellular microenvironment. In this work, gyroid titanium scaffolds were coated with a bioactive alginate-gelatin hydrogel. The addition of 45S5 bioactive glass enhanced the mechanical properties of the hydrogel and its adhesion strength. Furthermore, the developed hydrogels allowed for the penetration of gyroid scaffolds, demonstrating the potential of bioactive coatings for titanium implants.
CRIS-Team Scopus Importer:2025-06-06
Keywords: Bioactive Hydrogels; Hard-to-Soft Transition; Triple Periodic Minimal Surface

Female reproductive organs tissue engineering - Liverani, Liliana; Bleisinger, Nathalie; Beckmann, Matthias; Dittrich, Ralf (Elsevier, 2021)
The present chapter is focused on the tissue engineering approach applied to female reproductive organs. This field was quite often presented as urogenital applications, but recently the interest of the scientific community has been more oriented on the reproductive organs and to the evaluation of tissue engineering-based approaches focusing on the selection of biomaterials and scaffold fabrication technologies to develop suitable biomimetic three-dimensional constructs.
CRIS-Team Scopus Importer:2024-12-16
Keywords: Biomaterials; Fallopian tubes; Ovary; Reproductive organs; REPROTEN; Tissue engineering; Uterus

Ferrochrome Slag Feasibility as a Raw Material in Refractories: Evaluation of Thermo-physical and High Temperature Mechanical Properties - Karhu, Marjaana; Talling, Bob; Piotrowska, Patrycja; Matas Adams, Alba; Sengottuvelan, Abirami; Huttunen-Saarivirta, Elina; Boccaccini, Aldo R.; Lintunen, Pertti (Waste and Biomass Valorization, 2020)
This paper reports the characteristics of ferrochrome slag and its feasibility as aggregate in refractories aiming to substitute virgin refractory raw materials. Refractory castable specimens were formulated with ferrochrome slag as an aggregate and commercial calcium aluminate cement as a binder. Objective was to prepare refractory specimens with a maximum slag utilization but simultaneously to sustain good properties, comparable to those of virgin raw material refractory products. Mechanical and thermo-physical properties of the cured, dried and sintered specimens were characterized. Cold crushing strengths of best performing ferrochrome slag containing specimens were higher than 90 MPa and compressive strength values measured at 1200 °C were over 9 MPa. Thermal insulation properties were even better than those of commercial refractory reference, showing thermal conductivity values as low as λRT−1000 °C = 1.3 − 0.9 W/m K. The liquid phase formation above 1200 °C limits the ferrochrome slag use for refractory applications. Results suggest ferrochrome slag’s feasibility as an aggregate raw material for refractory materials up to temperatures of 1200 °C in air and up to temperatures of 700 °C in acidic gaseous atmosphere. Possible applications for this kind of novel refractory materials are, e.g., insulating secondary layers or bottom zones in metallurgical processes to substitute virgin refractories. A direct contact to molten metal must be avoided, but they are applicable as, e.g. floorings when exposed only to occasional melt droplets. Graphic Abstract: [Figure not available: see fulltext.]
CRIS-Team Scopus Importer:2020-06-02
Keywords: Electric arc furnace slag; Ferrochrome slag; Refractory ceramics; Slag valorisation

Fertility Preservation: Optimization of Follicle Extraction before Cultivation in the Artificial Ovary - Keckstein, P.; Fattahi, Amir; Liverani, Liliana; Dittrich, Ralf; Hoffmann, I; Boccaccini, Aldo R.; Beckmann, Matthias; Bleisinger, Nathalie (GEBURTSHILFE UND FRAUENHEILKUNDE, 2020)
CRIS-Team WoS Importer:2020-10-30

Ferulic acid and human platelet lysate incorporated alginate dialdehyde-gelatin 3D (bio)printable hydrogels with biological activity - Bider, Faina; Klotschan, Artem; Kuth, Sonja; Weisbach, Volker; Boccaccini, Aldo R. (Journal of Applied Polymer Science, 2024)
This study investigates the creation of multifunctional scaffolds based on alginate dialdehyde (ADA) and gelatin (GEL) incorporating ferulic acid (FA), a phytotherapeutic agent with diverse pharmacological properties, and human platelet lysate (HPL). The multimaterial hydrogels were characterized in terms of degradation/swelling behavior showing that HPL decelerates the degradation process of ADA-GEL hydrogels in absence of FA. A FA release study confirmed that the presence of HPL does not affect the FA release ability of ADA-GEL hydrogel. A trinitrobenzenesulfonic acid (TNBS) assay confirmed no influence of HPL on the Schiff's base formation. The addition of HPL was shown to lead to a decrease in stiffness, mechanical stability, and viscosity of ADA-GEL-HPL inks. This effect was also observed for ADA-GEL-HPL inks when investigating their three-dimensional (3D) printing ability. Cytocompatibility tests and a 3D bioprinting study confirmed the beneficial impact of the addition of HPL on MC3T3-E1 cells. Moreover, an antibacterial effect provided by the addition of FA was confirmed while the incorporation of HPL led to higher VEGF-A expression by MC3T3-E1 cells. Overall, the addition of HPL and FA to ADA-GEL hydrogel results in a promising ink, which has potential for future biofabrication applications.
CRIS-Team Scopus Importer:2024-07-26
Keywords: biocompatibility; biodegradable; bioprinting; hydrogels; synthesis and processing techniques

Fibronectin Functionalized Electrospun Fibers by Using Benign Solvents: Best Way to Achieve Effective Functionalization - Liverani, Liliana; Killian, Manuela; Boccaccini, Aldo R. (Frontiers in Bioengineering and Biotechnology, 2019)
The aim of this study is to demonstrate the feasibility of different functionalization methods for electrospun fibers developed using benign solvents. In particular three different approaches were investigated to achieve the functionalization of poly(epsilon caprolactone) (PCL) electrospun fibers with fibronectin. Protein surface entrapment, chemical functionalization and coaxial electrospinning were performed and compared. Moreover, bilayered scaffolds, with a top patterned and functionalized layer with fibronectin and a randomly oriented not functionalized layer were fabricated, demonstrating the versatility of the use of benign solvents for electrospinning also for the fabrication of complex graded structures. Besides the characterization of the morphology of the obtained scaffolds, ATR-FTIR and ToF-SIMS were used for the surface characterization of the functionalized fibers. Cell adhesion and proliferation were also investigated by using ST-2 cells. Positive results were obtained from all functionalized scaffolds and the most promising results were obtained with bilayered scaffolds, in terms of cells infiltration inside the fibrous structure.
CRIS-Team WoS Importer:2019-04-16

Fibrous protein-based biomaterials (silk, keratin, elastin, and resilin proteins) for tissue regeneration and repair - Costa, F.; Marques da Silva Lourenco, Raquel de Jesus; Boccaccini, Aldo R. (Peptides and Proteins as Biomaterials for Tissue Regeneration and Repair, 2018)
Tissue scaffolds are essential in tissue engineering approaches as they provide a tissue-mimicking environment for cells, with the aim to promote cell proliferation, cell differentiation, and tissue regeneration. To mimic better the microenvironment of native tissues, numerous techniques, and biomaterials have emerged in recent years. Among them, hydrogels formed from self-assembled biopolymer networks are particularly interesting. This chapter reviews the fabrication and use of fibrous protein-based hydrogels, with an emphasis on silk, keratin, elastin, and resilin proteins. Hydrogels formed by these proteins show structural, chemical, and mechanical similarities with the extracellular matrix of human tissues, typically exhibiting biological compatibility, and they can trigger specific cellular responses. In addition, these hydrogels can be degraded in the body by proteolytic enzymes. For these reasons, fibrous protein hydrogels are versatile materials for tissue engineering.
CRIS-Team Scopus Importer:2022-08-05
Keywords: Biomaterials; Cell-encapsulation; Fibrous-proteins; Hydrogels

Fibrous protein-based hydrogels for cell encapsulation - Silva, Raquel; Fabry, Ben; Boccaccini, Aldo R. (Biomaterials, 2014)
Tissue scaffolds play a vital role in tissue engineering by providing a native tissue-mimicking environment for cells, with the aim to promote cell proliferation, proper cell differentiation, and regeneration. To better mimic the microenvironment of native tissues, novel techniques and materials have emerged in recent years. Among them, hydrogels formed from self-assembled biopolymer networks are particularly interesting. This paper reviews the fabrication and use of fibrous protein-based hydrogels, with an emphasis on silk, keratin elastin and resilin proteins. Hydrogels formed by these proteins show close structural, chemical and mechanical similarities with the extracellular matrix, typically good biological compatibility, and they can trigger specific cellular responses. In addition, these hydrogels can be degraded in the body by proteolytic enzymes. For these reasons, fibrous protein hydrogels are one of the most versatile materials for tissue engineering. © 2014 Elsevier Ltd.
Keywords: Biomaterials; Cell-encapsulation; Fibrous-proteins; Hydrogels

Field-assisted sintering of barium titanate and 45S5 bioactive glass for biomedical applications - Polley, Christian; Riaz, Abdullah; Lund, Henrik; Boccaccini, Aldo R.; Seitz, Hermann (Ceramics International, 2024)
The development of electrically active biomaterials, which create electrical cues on demand to foster cellular stimulation, remains a challenge. Here, we utilized a Field-assisted sintering approach to densify barium titanate and 45S5 bioactive glass to create a piezoelectric and potentially bioactive composite. By using Field-assisted sintering, we aimed to fabricate dense piezoelectric specimens, preserving a low degree of crystallization of the bioactive glass to keep bioactivity as high as possible. Therefore, we have varied the compositions of the materials and processed them at different sintering temperatures. This enabled us to produce dense test specimens in the 94 %–98 % relative density range. The samples were successfully polarized, and piezoelectric charge constants d33 were determined for the composites. The content of bioactive glass and the sintering temperature influence the charge constant d33. It is in the range of 0.8–3.4 pC/N for the composites, approximately in the order of magnitude assigned to natural tissues such as bone. X-ray diffraction was used to analyze the composition of the processed samples and to investigate the influence of an additional thermal post-treatment. Altogether, we established a process window for field-assisted sintering, allowing the fabrication of a piezoelectric and potentially bioactive biomaterial for tissue engineering.
CRIS-Team Scopus Importer:2024-08-02

Fish scale containing alginate dialdehyde-gelatin bioink for bone tissue engineering - Kara Özenler, Aylin; Distler, Thomas; Tihminlioglu, Funda; Boccaccini, Aldo R. (Biofabrication, 2023)
The development of biomaterial inks suitable for biofabrication and mimicking the physicochemical properties of the extracellular matrix is essential for the application of bioprinting technology in tissue engineering (TE). The use of animal-derived proteinous materials, such as jellyfish collagen, or fish scale (FS) gelatin (GEL), has become an important pillar in biomaterial ink design to increase the bioactivity of hydrogels. However, besides the extraction of proteinous structures, the use of structurally intact FS as an additive could increase biocompatibility and bioactivity of hydrogels due to its organic (collagen) and inorganic (hydroxyapatite) contents, while simultaneously enhancing mechanical strength in three-dimensional (3D) printing applications. To test this hypothesis, we present here a composite biomaterial ink composed of FS and alginate dialdehyde (ADA)-GEL for 3D bioprinting applications. We fabricate 3D cell-laden hydrogels using mouse pre-osteoblast MC3T3-E1 cells. We evaluate the physicochemical and mechanical properties of FS incorporated ADA-GEL biomaterial inks as well as the bioactivity and cytocompatibility of cell-laden hydrogels. Due to the distinctive collagen orientation of the FS, the compressive strength of the hydrogels significantly increased with increasing FS particle content. Addition of FS also provided a tool to tune hydrogel stiffness. FS particles were homogeneously incorporated into the hydrogels. Particle-matrix integration was confirmed via scanning electron microscopy. FS incorporation in the ADA-GEL matrix increased the osteogenic differentiation of MC3T3-E1 cells in comparison to pristine ADA-GEL, as FS incorporation led to increased ALP activity and osteocalcin secretion of MC3T3-E1 cells. Due to the significantly increased stiffness and supported osteoinductivity of the hydrogels, FS structure as a natural collagen and hydroxyapatite source contributed to the biomaterial ink properties for bone engineering applications. Our findings indicate that ADA-GEL/FS represents a new biomaterial ink formulation with great potential for 3D bioprinting, and FS is confirmed as a promising additive for bone TE applications.
CRIS-Team Scopus Importer:2023-03-03
Keywords: alginates; bioink; bone tissue engineering; fish scale; gelatin

Flexible AgNW/PDMS nanocomposite for strain and pressure sensing - Kárason, Halldór; Ritrovato, Pierluigi; Maffulli, Nicola; Tortorella, Francesco; Boccaccini, Aldo R. (Materials Letters, 2024)
This study presents the fabrication and characterization of an ultra-thin (<1 mm) piezoresistive sensor based on a silver nanowire (AgNW) and polydimethylsiloxane (PDMS) nanocomposite, capable of simultaneous strain and pressure sensing. The sensor exhibits high sensitivity, detecting strains as low as 0.5 % with a range of up to 40 %, demonstrates frequency responsiveness from 0.5 to 3 Hz, and maintains functionality over 1000 cycles. The sensor's performance was evaluated through cyclic tensile and compressive tests. We hypothesize that the compression sensing mechanism is a consequence of the Poisson effect in the PDMS substrate, where transverse compression induces axial strains parallel to the AgNW network, causing disconnections within the nanowire matrix. The sensor's versatility was demonstrated through various biofeedback applications, including finger bending, applied pressure, calf raises, and elbow flexion. With its thin profile and dual-mode sensing capability, this AgNW/PDMS nanocomposite sensor shows promise for biomechanics, sports science, and healthcare monitoring applications.
CRIS-Team Scopus Importer:2024-10-11
Keywords: Electronic materials; Nanocomposite; Piezoresistivity; Sensors

Flexural strength of biopolymer coated bioactive glass (45S5) sintered struts for bone tissue engineering applications - Nawaz, Qaisar; Fiedler, Thomas; Biggemann, Jonas; Fey, Tobias; Boccaccini, Aldo R. (Materials Letters, 2023)
Owing to its bioactivity and proven biological performance, 45S5 bioactive glass (BG) is considered a convenient choice to fabricate scaffolds for bone tissue engineering applications. However, the brittleness of the material in conjunction with microstructural imperfections can cause catastrophic fracture and thus unreliable mechanical performance. This experimental study probes the fabrication of 45S5 BG struts using mold casting technique and sintering followed by the coating of the fabricated struts with gelatine and polycaprolactone (PCL) to improve the mechanical properties. The mechanical properties of struts were measured using a four-point bending test. The results indicate an improvement in flexural strength of the struts after coating with PCL. The uncoated and gelatin-coated samples exhibited flexural strength of around 20 MPa, which was increased to 55 MPa and 70 MPa after coating with PCL of 14 k and 80 k molecular weight, respectively. Careful evaluation of the test results permits quantifying the flexural strength of struts.
CRIS-Team Scopus Importer:2023-03-10
Keywords: Bioactive glasses; Flexural strength; Polymer coating; Scaffold; Sintering

Fly ash-based geopolymers containing added silicate waste. A review - Toniolo, Nicoletta; Boccaccini, Aldo R. (Ceramics International, 2017)
<span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif; font-size: medium;">This review summarizes different types of industrial wastes such as biomass ash, red mud, recycled glass and heavy metals waste, in their application for geopolymer production. These wastes, which are currently abundant and urgent to dispose of, cannot be used alone in the geopolymer process because they do not provide a suitable SiO<span style="box-sizing: border-box; position: relative; top: 0.4em; vertical-align: baseline; color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif;">2<span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif; font-size: medium;">/Al<span style="box-sizing: border-box; position: relative; top: 0.4em; vertical-align: baseline; color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif;">2<span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif; font-size: medium;">O<span style="box-sizing: border-box; position: relative; top: 0.4em; vertical-align: baseline; color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif;">3<span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", STIXGeneral, "Cambria Math", "Arial Unicode MS", sans-serif; font-size: medium;"> molar ratio for this technology. For this reason, these by-products are commonly used in addition to other aluminosilicate sources such as fly ash or metakaolin. Important parameters which affect the properties and performance of fly ash based geopolymers with addition of a variety of wastes are discussed based on a comprehensive literature review.
Keywords: Geopolymers; Fly ash

Fly-ash-based geopolymers: How the addition of recycled glass or red mud waste influences the structural and mechanical properties - Toniolo, Nicoletta; Taveri, Gianmarco; Hurle, Katrin; Roether, Judith; Ercole, P; Dlouhy⁠, Ivo; Boccaccini, Aldo R. (Journal of Ceramic Science and Technology, 2017)
Keywords: Fly ash; Geopolymers; Red mud; Waste glass

Formation and in vitro biocompatibility of biomimetic hydroxyapatite coatings on chemically treated carbon substrates - Hoppe, Alexander; Will, Julia; Detsch, Rainer; Boccaccini, Aldo R.; Greil, Peter (Journal of Biomedical Materials Research Part A, 2013)
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.format

Formation of osteoclast-like cells on HA and TCP ceramics - Detsch, Rainer; et al. (Acta Biomaterialia, 2008)
An essential property of bone substitute materials is that they are integrated into the natural bone remodelling process, which involves the resorption by osteoclast cells and the formation by osteoblast cells. If monocyte cells adhere to a calcium phosphate surface (bone or bone substitute material), they can fuse together and form multinucleated osteoclast cells. In this study we show that osteoclast-like cells derived from a human leukoma monocytic lineage responded in a different way to tricalciumphosphate (TCP) than to hydroxyapatite (HA) ceramics. Both ceramics were degraded by resorbing cells; however, HA enhanced the formation of giant cells. The osteoclast-like cells on HA formed a more pronounced actin ring, and larger lacunas could be observed. TCP ceramics are medically used as bone substitute materials because of their high dissolution rate. On the other hand, highly soluble calcium phosphate ceramics like TCP seem to be inappropriate for osteoclast resorption because they produce a high calcium concentration in the osteoclast interface and in the environment. © 2007 Acta Materialia Inc.
Keywords: Bioresorption; Calcium phosphate; Degradation; Monocyte; Osteoclast

Formation of Zein/Bioactive Glass Layers Using Electrophoretic Deposition Technique - Ramos Rivera, Laura; Dippel, Jannik; Boccaccini, Aldo R. (ECS Transactions, 2018)
Coatings of zein and zein/bioactive glass composites were produced on 316L stainless steel using anodic electrophoretic deposition (EPD). Zein and 45S5 bioactive glass were dispersed in a binary water/ethanol solution. The effects of the zein and bioactive glass concentrations as well as different water/ethanol ratios on the coating characteristics were investigated. Also, the influence of applied voltage and deposition time were analyzed. Prior to EPD, the zeta potential of zein, bioactive glass and zein/bioactive glass suspensions were measured as a function of the pH. The coatings were investigated by optical microscopy, scanning electron microscopy and atomic force microscopy. Coatings with pure zein are homogeneous when using an electrical field strength below or equal to 0.05 V/m. Higher voltages led to a discoloration of the solution which could result from a conformational change of zein. The co-deposition of zein/bioactive glass is very sensitive to the applied voltage and the concentration of zein. High concentrations of zein (10 g/L) increase the viscosity of the solution and reduce the electrophoretic mobility of the bioactive glass. Equal concentration of zein and bioactive glass at a pH of 7.5 with a low electric field strength were found to be the optimum condition

From Thermogelling Hydrogels toward Functional Bioinks: Controlled Modification and Cytocompatible Crosslinking - Hahn, Lukas; Beudert, Matthias; Gutmann, Marcus; Kessler, Larissa; Stahlhut, Philipp; Fischer, Lena; Karakaya, Emine; Lorson, Thomas; Thievessen, Ingo; Detsch, Rainer; Luehmann, Tessa; Luxenhofer, Robert (Macromolecular Bioscience, 2021)
Hydrogels are key components in bioink formulations to ensure printability and stability in biofabrication. In this study, a well-known Diels-Alder two-step post-polymerization modification approach is introduced into thermogelling diblock copolymers, comprising poly(2-methyl-2-oxazoline) and thermoresponsive poly(2-n-propyl-2-oxazine). The diblock copolymers are partially hydrolyzed and subsequently modified by acid/amine coupling with furan and maleimide moieties. While the thermogelling and shear-thinning properties allow excellent printability, trigger-less cell-friendly Diels-Alder click-chemistry yields long-term shape-fidelity. The introduced platform enables easy incorporation of cell-binding moieties (RGD-peptide) for cellular interaction. The hydrogel is functionalized with RGD-peptides using thiol-maleimide chemistry and cell proliferation as well as morphology of fibroblasts seeded on top of the hydrogels confirm the cell adhesion facilitated by the peptides. Finally, bioink formulations are tested for biocompatibility by incorporating fibroblasts homogenously inside the polymer solution pre-printing. After the printing and crosslinking process good cytocompatibility is confirmed. The established bioink system combines a two-step approach by physical precursor gelation followed by an additional chemical stabilization, offering a broad versatility for further biomechanical adaptation or bioresponsive peptide modification.
CRIS-Team Scopus Importer:2021-08-06
Keywords: biofabrication; bioprinting; chemical crosslinking; hydrogels

Functional behavior of chitosan/gelatin/silica-gentamicin coatings by electrophoretic deposition on surgical grade stainless steel - Aydemir, Tuba; Liverani, Liliana; Pastore, Juan I.; Ceré, Silvia M.; Goldmann, Wolfgang; Boccaccini, Aldo R.; Ballarre, Josefina (Materials Science and Engineering C, 2020)
Metals are used in several orthopedic applications as fixation elements for the stabilization of fractures or as prostheses. One of the most common orthopedic biomaterials in many developing countries is surgical grade stainless steel (SS). However, its use as permanent implant in orthopedic surgery is conditioned due to its limited corrosion resistance in physiological media, lack of osseointegration, and absence of antibacterial effect. The aim of this work is to generate a degradable coating with antibacterial properties for stainless steel to be used in implants/medical devices. The coating is composed of a biopolymer/silica-gentamicin nanoparticles composite obtained by electrophoretic deposition (EPD) on surgical grade stainless steel plates. The coating surface was characterized by microscopic examination, and in vitro performance was evaluated after immersion in phosphate-buffered saline (PBS) solution, simulated body fluid (SBF), and cell culture medium, to analyze coating degradation, antibiotics release, cell attachment (ST-2 stromal cells), and antibacterial (Escherichia coli and Staphylococcus aureus) properties. EPD coatings were uniform and covered homogeneously the surface of the SS substrate. Also the distribution of silica-gentamicin nanoparticles was homogeneous on the coated area. The degradation of the chitosan-gelatin coatings was evident after 7 days of immersion. The gentamicin release led to excellent antibacterial behavior at 24 h, meanwhile the cell proliferation (at 7 days culture) was not inhibited. The results show that the coating system exhibits promising behavior which could contribute to prevent hospital infections at early implantation times.
CRIS-Team Scopus Importer:2020-06-02
Keywords: Chitosan; Electrophoretic deposition; Gelatin; Prevention of infections; Silica-gentamicin nanoparticles; Stainless steel implants

Functional Glasses and Glass-ceramics Derived from Industrial Waste - Chinnam, Rama Krishna Satish (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2014)

Functionalization of graphene by electrophilic alkylation of reduced graphite - Englert, Jan; Knirsch, Kathrin; Dotzer, Christoph; Butz, Benjamin; Hauke, Frank; Hirsch, Andreas; Spiecker, Erdmann (Chemical Communications, 2012)
The reaction of Na/K-reduced graphite with hexyliodide represents a new, versatile and mild approach to synthesize alkylated graphene derivatives, which were characterized by a combination of Raman spectroscopy, TEM and TGA/MS analysis. © The Royal Society of Chemistry 2012.

Functionalization of steel surfaces with organic acids: Influence on wetting and corrosion behavior - Alonso Frank, Micael; Meltzer, Christian; Braunschweig, Björn; Peukert, Wolfgang; Boccaccini, Aldo R.; Virtanen, Sannakaisa (Applied Surface Science, 2017)
Self-assembled monolayers (SAMs) have been used to tailor surface properties of different metal surfaces. Typically SAMs can be bound to surface hydroxyls of a thin oxide layer that forms on the surface of a less noble metal and dominates its properties. The effects of SAMs with different anchoring groups and chain lengths regarding wettability, corrosion resistance and homogeneity of the layer were studied in detail. Alkyl carbonic and phosphonic acids were selected to create a hydrophobic layer on the surface of stainless steel ASIS 316L and on carbon steel N80. SAMs were formed by dip-coating of the samples in an organic acid ethanolic solution. Sum frequency generation (SFG) analysis together with contact angle and electrochemical measurements were carried out to explore correlations between tailored wettability, corrosion resistance, and layer homogeneity on one side, and the chain length, anchor group, concentration and immersion time on the other side. The homogeneity of the layers as well as the resulting surface hydrophobicity increased with an increase of the immersion time, the contact angle reached a maximum (ca. 120°) for an immersion time of approximately 2 days.
Keywords: Carbon steel N80; Hydrophobicity; Myristic acid; Octadecylphosphonic acid (ODPA); Stainless steel 316 L; Stearic acid; Sum frequency generation; Surface functionalization

Functionalized nanofibers as drug-delivery systems for osteochondral regeneration - Amler, Evzen; Filova, Eva; Buzgo, Matej; Prosecka, Eva; Rampichova, Michala; Necas, Alois; Nooeaid, Patcharakamon; Boccaccini, Aldo R. (Nanomedicine, 2014)
A wide range of drug-delivery systems are currently attracting the attention of researchers. Nanofibers are very interesting carriers for drug delivery. This is because nanofibers are versatile, flexible, nanobiomimetic and similar to extracellular matrix components, possible to be functionalized both on their surface as well as in their core, and also because they can be produced easily and cost effectively. There have been increasing attempts to use nanofibers in the construction of a range of tissues, including cartilage and bone. Nanofibers have also been favorably engaged as a drug-delivery system in cell-free scaffolds. This short overview is devoted to current applications and to further perspectives of nanofibers as drug-delivery devices in the field of cartilage and bone regeneration, and also in osteochondral reconstruction. © 2014 Future Medicine Ltd.
Keywords: bone; cartilage; drug delivery; electrospinning; liposome; nanofiber

Functional properties of glass-ceramic composites containing industrial inorganic waste and evaluation of their biological compatibility - Rozenstrauha, I.; Lodins, E.; Krage, L.; Drille, M.; Balode, M.; Putna, I.; Filipenkov, V.; Chinnam, Rama Krishna Satish; Boccaccini, Aldo R. (Ceramics International, 2013)
A study has been carried out on the feasibility of using Latvian industrial waste (peat cool ash, fly ash, aluminium scrap metal processing waste, metallurgical slag and waste cullet glass) and raw mineral materials (limeless clay) to produce dense, frost resistant, chemically durable glass-ceramic materials by powder technology. Highly crystalline and dense products (density: 2.50-2.94 g/cm3, water uptake: 1.3-4.3%) were fabricated from different mixtures by sintering at temperatures in the range of 1060-1160° C. Glass-ceramics were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and four point bending strength test. Chemical durability, soluble salt crystallization as well as biological tests were carried out in order to evaluate the environmental stability and possible toxicity of the materials. The novel glass-ceramics developed here can find applications as building materials, such as wall tiles and for manufacturing industrial floors. © 2013 Elsevier Ltd and Techna Group S.r.l.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.functi
Keywords: Chemical durability; D. Glass-ceramic; Industrial waste; Toxicity

Futures of BME: Sustainable medical materials 2023 - Ramakrishna, Seeram; Boccaccini, Aldo R.; Zare, Mina (Current Opinion in Biomedical Engineering, 2023)
CRIS-Team Scopus Importer:2023-11-10

Ga and Ce ion-doped phosphate glass fibres with antibacterial properties and their composite for wound healing applications - Lapa, Agata; Cresswell, Mark; Campbell, Ian; Jackson, Phil; Goldmann, Wolfgang; Detsch, Rainer; Parsons, Andrew; Ahmed, Ifty; Boccaccini, Aldo R. (Journal of Materials Chemistry B, 2019)
Novel gallium/cerium-doped phosphate glass fibres (PGF) were successfully manufactured by the melt-quenching and melt-spinning process. The amorphous character of the materials produced was confirmed using X-ray powder diffraction (XRD), and the elemental composition was investigated with X-ray fluorescence confirming the presence of 2 mol% of Ga2O3 or CeO2. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of Q1 and Q2 structural phosphate species. Mechanical properties of the PGFs revealed tensile strength values of 428 ± 94 MPa and 379 ± 80 MPa, with elastic modulus values of 45 ± 4 GPa and 54 ± 9 GPa for Ce-PGF (diameter 25 μm) and Ga-PGF (diameter 18 μm), respectively. The influence of both dopants on the glass degradation properties was evaluated by tests in deionised water, which revealed a decreased dissolution rate for gallium-doped PGF in comparison to cerium-doped PGF. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) measurements were used to explore ion release in cell culture medium, while ICP-mass spectrometry (ICP-MS) was used to measure ion release in deionised water. These techniques showed controlled release of therapeutic and antibacterial ions from the PGF. Antibacterial properties of Ce-PGF and Ga-PGF, based on turbidity measurements, were confirmed against Gram-positive bacteria. Moreover, Ce-doped phosphate glass fibres did not disturb the proliferation of human epidermal keratinocyte (HaCaT) cells or the mobility of mice embryonic fibroblasts (MEF). Applying an in vitro scratch assay showed full wound closure after 24 h of indirect incubation with Ga-PGF. Due to their superior processability as compared with Ga-PGFs, a fully degradable mesh based on Ce-PGF was designed and found to achieve high water uptake (up to 800%), suggesting its suitability for wound healing applications.
CRIS-Team Scopus Importer:2019-11-22

Gallium- and Cerium-Doped Phosphate Glasses with Antibacterial Properties for Medical Applications - Lapa, Agata; Cresswell, Mark; Campbell, Ian; Jackson, Phil; Goldmann, Wolfgang H.; Detsch, Rainer; Boccaccini, Aldo R. (Advanced Engineering Materials, 2020)
Novel cerium- (Ce) and gallium (Ga)-doped phosphate glasses (PGs) are successfully obtained by the peroxidation method. The new glasses are characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction, inductively coupled plasma-optical emission spectroscopy (ICP-OES), and pH measurements. A strong correlation between glass properties and their composition is found. The incorporation of Ga/Ce in the glass structure is confirmed by peak shifts in Raman and FTIR spectra. Degradation tests conducted in water confirm the soluble character of the PGs and reveal the influence of Ga and Ce on the degradation rate. Ga-doped glasses are found to be less soluble than Ce-doped ones (43%, 33%, 21%, and 16% of dry mass remained after 7 weeks for 7Ga, 5Ga, 5Ce, and 7Ce, respectively). Biological evaluation using ST-2 cells shows adequate cell response with a cell viability of 80% measured using the indirect contact method depending on the composition. The cell viability decreases with an increase in Ga content and increases with Ce content. The antibacterial character of Ga/Ce-doped PGs is confirmed by turbidity measurements against Escherichia coli and Staphylococcus carnosus. The novel Ce/Ga-doped PGs exhibiting antibacterial properties and biocompatibility reported here are interesting for tissue engineering and wound healing applications.
CRIS-Team Scopus Importer:2020-03-17
Keywords: antibacterial properties; cerium; gallium; ion release; medical applications; phosphate glasses

Gallium containing bioactive materials: A review of anticancer, antibacterial, and osteogenic properties - Kurtuldu, Fatih; Mutlu, Nurshen; Boccaccini, Aldo R.; Galusek, Dušan (Bioactive Materials, 2022)
The incorporation of gallium into bioactive materials has been reported to enhance osteogenesis, to influence blood clotting, and to induce anti-cancer and anti-bacterial activity. Gallium-doped biomaterials prepared by various techniques include melt-derived and sol-gel-derived bioactive glasses, calcium phosphate bioceramics, metals and coatings. In this review, we summarize the recently reported developments in antibacterial, anticancer, osteogenesis, and hemostasis properties of Ga-doped biomaterials and briefly outline the mechanisms leading to Ga biological effects. The key finding is that gallium addition to biomaterials has great potential for treating bone-related diseases since it can be efficiently transferred to the desired region at a controllable rate. Besides, it can be used as a potential substitute for antibiotics for the inhibition of infections during the initial and advanced phases of the wound healing process. Ga is also used as an anticancer agent due to the increased concentration of gallium around excessive cell proliferation (tumor) sites. Moreover, we highlight the possibility to design different therapeutic approaches aimed at increasing the efficiency of the use of gallium containing bioactive materials for multifunctional applications.
CRIS-Team Scopus Importer:2022-01-21
Keywords: Antibacterial; Bioactive materials; Cancer treatment; Hemostasis; Osteogenesis

Gallium-containing mesoporous nanoparticles influence in-vitro osteogenic and osteoclastic activity - Kurtuldu, Fatih; Mutlu, Nurshen; Friedrich, Ralf P.; Beltrán, Ana M.; Liverani, Liliana; Detsch, Rainer; Alexiou, Christoph; Galusek, Dušan; Boccaccini, Aldo R. (Biomaterials Advances, 2024)
Mesoporous silica nanoparticles were synthesized using a microemulsion-assisted sol-gel method, and calcium, gallium or a combination of both, were used as dopants. The influence of these metallic ions on the physicochemical properties of the nanoparticles was investigated by scanning and transmission electron microscopy, as well as N2 adsorption-desorption methods. The presence of calcium had a significant impact on the morphology and textural features of the nanoparticles. The addition of calcium increased the average diameter of the nanoparticles from 80 nm to 150 nm, while decreasing their specific surface area from 972 m2/g to 344 m2/g. The nanoparticles of all compositions were spheroidal, with a disordered mesoporous structure. An ion release study in cell culture medium demonstrated that gallium was released from the nanoparticles in a sustained manner. In direct contact with concentrations of up to 100 μg/mL of the nanoparticles, gallium-containing nanoparticles did not exhibit cytotoxicity towards pre-osteoblast MC3T3-E1 cells. Moreover, in vitro cell culture tests revealed that the addition of gallium to the nanoparticles enhanced osteogenic activity. Simultaneously, the nanoparticles disrupted the osteoclast differentiation of RAW 264.7 macrophage cells. These findings suggest that gallium-containing nanoparticles possess favorable physicochemical properties and biological characteristics, making them promising candidates for applications in bone tissue regeneration, particularly for unphysiological or pathological conditions such as osteoporosis.
CRIS-Team Scopus Importer:2024-06-21
Keywords: Bioactive glasses; Gallium; Mesoporous silica nanoparticles; Osteoblast; Osteoclast

Gelatin coated 45S5 Bioglass®-derived scaffolds for bone tissue engineering - Metze, Anke-Lisa; Grimm, Alexandra; Nooeaid, Patcharakamon; Roether, Judith; Hum, Jasmin; Newby, Phillipa; Schubert, Dirk W.; Boccaccini, Aldo R. (Key Engineering Materials, 2013)
Highly porous 45S5 Bioglass® scaffolds were fabricated by the foam replica method and successfully coated with a well attached gelatin layer by dipping and pipetting methods. Depending on macropore size of the scaffold and gelatin concentration, mechanically enhanced scaffolds with improved compressive strength in comparison to uncoated scaffolds could be obtained while preserving the high and interconnected porosity that is required for bone in-growth. Moreover, the scaffolds bioactivity by immersion in simulated body fluid (SBF) was investigated showing that gelatin coating preserves the intrinsic bioactivity of the Bioglass® scaffold. It was also shown that the gelatin layer can be loaded with tetracycline hydrochloride for developing scaffolds with drug delivery capability.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.gelati
Keywords: 45S5 Bioglass®; Gelatin; Scaffold; Tetracycline Hydrochloride

Gelatin coating increases in vivo bone formation capacity of three-dimensional 45S5 bioactive glass-based crystalline scaffolds - Westhauser, Fabian; Senger, Anne-Sophie; Obert, David; Ciraldo, Francesca; Schuhladen, Katharina; Schmidmaier, Gerhard; Moghaddam, Arash; Boccaccini, Aldo R. (Journal of Tissue Engineering and Regenerative Medicine, 2019)
Recent studies have demonstrated that surface characteristics, porosity, and mechanical strength of three-dimensional 45S5-type bioactive glass (BG)-based scaffolds are directly correlated with osteogenic properties. Three-dimensional BG-based scaffolds obtained from maritime natural sponges (MNSs) as sacrificial templates exhibit the required morphological properties; however, no in vivo data about the osteogenic features are available. In this study, uncoated (Group A) and gelatin-coated (Group B) crystalline MNS-obtained BG-based scaffolds were evaluated mechanically and seeded with human mesenchymal stem cells prior to subcutaneous implantation in immunodeficient mice. Before implantation and after explantation, micro-computed tomography scans were conducted, and scaffolds were finally subjected to histomorphometry. Scaffolds of both groups showed bone formation. However, Group B scaffolds performed distinctly better as indicated by a significant increase in scaffold volume (8.95%, p = 0.039) over the implantation period compared with a nonsignificant increase of 5.26% in Group A scaffolds in micro-computed tomography analysis. Furthermore, percentage bone area was 10.33% (+/- 1.18%) in the Group B scaffolds, which was significantly (p = 0.007) higher compared with the 8.53% (+/- 0.77%) in the Group A scaffolds in histomorphometry. Compressive strength was enhanced significantly by gelatin coating (9 +/- 2 vs. 4 +/- 1 MPa; p = 0.029). The presence of gelatin on the remnant parts was verified by scanning electron microscopy and X-ray spectroscopy, demonstrating the coatings' resilience. MNS-obtained BG-based scaffolds were thus confirmed to exhibit osteogenic properties in vivo that can significantly be enhanced by gelatin coating.
CRIS-Team WoS Importer:2019-03-15

Gelatin Methacryloyl (GelMA) - 45S5 Bioactive Glass (BG) Composites for Bone Tissue Engineering: 3D Extrusion Printability and Cytocompatibility Assessment Using Human Osteoblasts - Akhtar, Memoona; Peng, Peixi; Bernhardt, Anne; Gelinsky, Michael; Ur Rehman, Muhammad Atiq; Boccaccini, Aldo R.; Basu, Bikramjit (ACS Biomaterials Science and Engineering, 2024)
3D extrusion printing has been widely investigated for low-volume production of complex-shaped scaffolds for tissue regeneration. Gelatin methacryloyl (GelMA) is used as a baseline material for the synthesis of biomaterial inks, often with organic/inorganic fillers, to obtain a balance between good printability and biophysical properties. The present study demonstrates how 45S5 bioactive glass (BG) addition and GelMA concentrations can be tailored to develop GelMA composite scaffolds with good printability and buildability. The experimental results suggest that 45S5 BG addition consistently decreases the compression stiffness, irrespective of GelMA concentration, albeit within 20% of the baseline scaffold (without 45S5 BG). The optimal addition of 2 wt % 45S5 BG in 7.5 wt % GelMA was demonstrated to provide the best combination of printability and buildability in the 3D extrusion printing route. The degradation decreases and the swelling kinetics increases with 45S5 BG addition, irrespective of GelMA concentration. Importantly, the dissolution in simulated body fluid over 3 weeks clearly promoted the nucleation and growth of crystalline calcium phosphate particles, indicating the potential of GelMA-45S5 BG to promote biomineralization. The cytocompatibility assessment using human osteoblasts could demonstrate uncompromised cell proliferation or osteogenic marker expression over 21 days in culture for 3D printable 7.5 wt % GelMA −2 wt % 45S5 BG scaffolds when compared to 7.5 wt % GelMA. The results thus encourage further investigations of the GelMA/45S5 BG composite system for bone tissue engineering applications.
CRIS-Team Scopus Importer:2024-08-02
Keywords: 3D extrusion printing; 45S5 bioactive glass; bone tissue engineering; GelMA hydrogel

Generation of composites for bone tissue-engineering applications consisting of gellan gum hydrogels mineralized with calcium and magnesium phosphate phases by enzymatic means - Douglas, Timothy E L; Krawczyk, Grzegorz; Pamula, Elzbieta; Declercq, Heidi A.; Schaubroeck, David; Bucko, Miroslaw M.; Balcaen, Lieve; Van Der Voort, Pascal; Bliznuk, Vitaliy; van den Vreken, Natasja M F; Dash, Mamoni; Detsch, Rainer; et al. (Journal of Tissue Engineering and Regenerative Medicine, 2014)
Mineralization of hydrogels, desirable for bone regeneration applications, may be achieved enzymatically by incorporation of alkaline phosphatase (ALP). ALP-loaded gellan gum (GG) hydrogels were mineralized by incubation in mineralization media containing calcium and/or magnesium glycerophosphate (CaGP, MgGP). Mineralization media with CaGP:MgGP concentrations 0.1:0, 0.075:0.025, 0.05:0.05, 0.025:0.075 and 0:0.1 (all values mol/dm, denoted A, B, C, D and E, respectively) were compared. Mineral formation was confirmed by IR and Raman, SEM, ICP-OES, XRD, TEM, SAED, TGA and increases in the the mass fraction of the hydrogel not consisting of water. Ca was incorporated into mineral to a greater extent than Mg in samples mineralized in media A-D. Mg content and amorphicity of mineral formed increased in the order A<b<c<d. mineral="" formed="" in="" media="" a="" and="" b="" was="" calcium-deficient="" hydroxyapatite="" (cdha).="" medium="" c="" combination="" of="" cdha="" an="" amorphous="" phase.="" d="" e="" crystalline="" mgp.="" young's="" moduli="" storage="" decreased="" dependence="" mineralization="" the="" order="">B>C>D, but were significantly higher for samples mineralized in medium E. The attachment and vitality of osteoblastic MC3T3-E1 cells were higher on samples mineralized in media B-E (containing Mg) than in those mineralized in medium A (not containing Mg). All samples underwent degradation and supported the adhesion of RAW 264.7 monocytic cells, and samples mineralized in media A and B supported osteoclast-like cell formation. © 2014 John Wiley & Sons, Ltd.
Keywords: Calcium phosphate; Composite; Cytocompatibility; Enzyme; Gellan gum; Hydrogel; Magnesium phosphate; Osteoblast

Genipin-Cross-Linked Silk Fibroin/Alginate Dialdehyde Hydrogel with Tunable Gelation Kinetics, Degradability, and Mechanical Properties: A Potential Candidate for Tissue Regeneration - Vaziri, Asmasadat; Vasheghani-Farahani, Ebrahim; Hosseinzadeh, Simzar; Bagheri, Fatemeh; Büchner, Margitta; Schubert, Dirk W.; Boccaccini, Aldo R. (Biomacromolecules, 2024)
Genipin-cross-linked silk fibroin (SF) hydrogel is considered to be biocompatible and mechanically robust. However, its use remains a challenge for in situ forming applications due to its prolonged gelation process. In our attempt to facilitate the in situ fabrication of a genipin-mediated SF hydrogel, alginate dialdehyde (ADA) was utilized as a reinforcement template. Here, SF/ADA-based hydrogels with different compositions were synthesized covalently and ionically. Incorporating ADA into the SF hydrogel increased pore size (44.66-174.66 μm), porosity (61.59-80.40%), and the equilibrium swelling degree (7.60-30.17). Moreover, a wide range of storage modulus and compressive modulus were obtained by adjusting the proportions of SF and ADA networks within the hydrogel. The in vitro cell analysis using preosteoblast cells (MC3T3-E1) demonstrated the cytocompatibility of all hydrogels. Overall, the covalently and ionically cross-linked SF/ADA hydrogel represents a promising solution for in situ forming hydrogels for applications in tissue regeneration.
CRIS-Team Scopus Importer:2024-10-18
Keywords: Biopolymers; Gelation; Hydrogels; Nucleic acid structure; Peptides and proteins

Geopolymers from DC plasma-treated air polution control residues, metakaolin, and granulated blast furnace slag - Kourti, I.; Rani, D. Amutha; Boccaccini, Aldo R.; Cheeseman, C. R. (Journal of Materials in Civil Engineering, 2011)
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.geopol

Geopolymers from DC plasma treated APC residues, metakaolin and GGBFS, ASCE's - Boccaccini, Aldo R.; et al. (Journal of Materials in Civil Engineering, 2010)
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.geopol

Glass and glass-ceramic matrix composites for advanced applications: Part II: Applications - Boccaccini, Dino; Cannio, Maria; Bernardo, Enrico; Boccaccini, Aldo R. (Elsevier, 2021)
CRIS-Team Scopus Importer:2021-11-19

Glass and glass-ceramic matrix composites for advanced applications: Part I: Properties and manufacturing technologies - Boccaccini, Dino; Cannio, Maria; Bernardo, Enrico; Boccaccini, Aldo R. (Elsevier, 2021)
CRIS-Team Scopus Importer:2021-11-19

Glass-ceramic composites from borosilicate glass and alumina-rich residues - Chinnam, Rama Krishna Satish; Boccaccini, Aldo R.; Bernardo, Enrico; Epstein, Howard (International Journal of Applied Ceramic Technology, 2015)
Valoxy, an alumina-rich waste, was mixed with borosilicate glass (BSG) powder in 10, 20, and 30 wt% concentrations. Sintering was carried out at 850 and 950°C for 30 min. Glass-ceramics (GC) were characterized by X-ray diffraction analysis and scanning electron microscopy. Diametral compression strength (DCS) tests were performed on sintered samples before and after thermal shock. GC samples containing calcined Valoxy showed superior properties in all compositions and processing temperatures compared with samples containing as-received Valoxy. Maximum density of 2.2 g/cm3, water absorption below 1 wt% and DCS of ∼24MPa were measured for 10 wt% calcined Valoxy + BSG GC composites sintered at 850°C.

Glass-Ceramic Foams from "Weak Alkali Activation' and Gel-Casting of Waste Glass/Fly Ash Mixtures - Romero, Acacio Rincon; Toniolo, Nicoletta; Boccaccini, Aldo R.; Bernardo, Enrico (Materials, 2019)
A weak alkali activation' was applied to aqueous suspensions based on soda lime glass and coal fly ash. Unlike in actual geopolymers, an extensive formation of zeolite-like gels was not expected, due to the low molarity of the alkali activator (NaOH) used. In any case, the suspension underwent gelation and presented a marked pseudoplastic behavior. A significant foaming could be achieved by air incorporation, in turn resulting from intensive mechanical stirring (with the help of a surfactant), before complete hardening. Dried foams were later subjected to heat treatment at 700-900 degrees C. The interactions between glass and fly ash, upon firing, determined the formation of new crystal phases, particularly nepheline (sodium alumino-silicate), with remarkable crushing strength (6 MPa, with a porosity of about 70%). The fired materials, finally, demonstrated a successful stabilization of pollutants from fly ash and a low thermal conductivity that could be exploited for building applications.
CRIS-Team WoS Importer:2019-03-26
Keywords: Fly ash; Alkali activation; Inorganic gel casting; Glass-ceramic foams; Waste glass

Glass-ceramic proppants from sinter-crystallisation of waste-derived glasses - Toniolo, Nicoletta; Rincon Romero, Acacio; Marangoni, Mauro; Binhussain, Mohammed; Boccaccini, Aldo R.; Bernardo, Enrico (Advances in Applied Ceramics, 2017)
Keywords: crystallisation; Glass-ceramics; hydraulic fracking; proppant; sintering

Glass-ceramic seal to join Crofer 22 APU alloy to YSZ ceramic in planar SOFCs - Smeacetto, F.; Salvo, M.; Ferraris, M.; Cho, J.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2008)
This work describes the design and development of a glass-ceramic seal to produce a hermetic joint between the ceramic electrolyte and the metallic interconnect of planar SOFC stacks. The glass-ceramic composition was designed considering the chemical compatibility with the ceramic electrolyte (yttria stabilized zirconia) and the oxidation resistant metal alloy interconnect (Crofer 22 APU), the thermo-mechanical properties (characteristic temperatures, thermal expansion coefficient), and the wettability on the substrates. The designed glass-ceramic seal is a barium-free silica-based glass, which partially crystallizes during the heat treatment after being deposited on Crofer 22 APU substrate by slurry coating or by electrophoretic deposition. The sealing process of the glass-ceramic was optimized, also taking into account that the maximum processing temperature should be lower that 950 °C (upper limit for the metallic interconnect) and the maximum heating rate of about 5 °C/min (limit for ceramic components). The joined ceramic/seal/metal samples were morphologically characterized and preliminary tested for 400 h in air atmosphere at the fuel cell operating temperature of 800 °C. Thermal ageing in air caused a Cr-diffusion from Crofer 22 APU alloy to the seal only when the alloy was used in the as-received condition. The preoxidised one did not diffuse Cr ions through the seal under the same ageing conditions. © 2007 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.glassc
Keywords: Fuel cell; Glass-ceramic; Interconnect; Joining

Glass-ceramics from plasma treated air pollution control (APC) residues - Amutha Rani, D.; Roether, J. A.; Gomez, E.; Deegan, D. E.; Cheeseman, C. R.; Boccaccini, Aldo R. (Glass Technology, 2009)
Air pollution control (APC) residues from a UK energy from waste plant were blended with alumina and silica, and melted using DC plasma arc technology to produce a glass. Results from the compliance leaching test BS EN12457-4 demonstrated that the APC residue derived glass released only trace levels of metals, e.g. Pb (0-011 mg/kg), Zn (0-009 mg/kg) and Cl- (0-2 mg/kg). These are significantly below the waste acceptance criteria (WAC) limit values for the disposal of waste to inert landfill. A powder processing method was used to convert the APC residues derived glass to a glass-ceramic during which the crystallisation behaviour and microstructural features were studied. Our results have shown that plasma treatment of APC residues produces an inert glass that has potential applications as a bulk material in civil engineering applications, or as a higher value glass-ceramic product after a crystallisation heat treatment.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.glassc

Glass-Ceramic Tiles Prepared by Pressing and Sintering DC Plasma-Vitrified Air Pollution Control Residues - Devaraj, Amutha Rani; Cheeseman, Chris R.; Boccaccini, Aldo R.; Deegan, David (International Journal of Applied Ceramic Technology, 2010)
Air pollution control (APC) residues produced from cleaning gas emissions at energy from waste (EfW) plants processing municipal solid waste are a problematic hazardous waste. In this research they have been treated using DC plasma technology and this produces an inert glass. Glass-ceramic tiles were prepared by powder pressing and sintering fritted APC residue-derived glass. Tile samples prepared with high levels of plasma treated APC residue glass had comparable physical properties to commercially available ceramics such as porcelain and monoporosa, with high bulk density (2.4 g/cm3), low water absorption (<6%) and high flexural strength (∼60 MPa). © 2009 The American Ceramic Society.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.glassc

Glasses and ceramics from waste - Colombo, Paolo; Boccaccini, Aldo R.; Lee, W. E. (Bill) (Advances in Applied Ceramics, 2009)
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.glasse

Glasses in Healthcare Preface - Boccaccini, Aldo R.; Rahaman, Mohamed N. (Journal of Non-Crystalline Solids, 2016)

Glass matrix composites for transparent security measures - Boccaccini, Aldo R.; McPhail, David; Pang, Bo (Materials World, 2011)
The work at Imperial College London is processing and characterizing a range of opto-mechanical composites with a focus on alumina fiber-reinforced borosilicate glass matrix composites. In a typical experiment, oxalic acid solution is slowly poured into zirconyl chloride octahydrate solution and mixed under constant stirring. The air inside the fiber bundle can be evacuated using a vacuum pump. As the air is extracted, the sol is seen to bubble. Coated fibers are heat treated at 500°C for three hours at a slow heating rate of one degree per minute to diminish surface cracking. Sintering occurs at 1300°C after this calcination step. A hybrid sol-gel coating method has been developed to improve the coated surface's quality. After surface treatment, the composite exhibits qualitatively good transparency. The average strength of the composites is found to be in the range 30-4OMPa, with decreased spacing and increased fiber content resulting in a slightly higher average flexural strength.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.glassm

Gradients, Singularities and Interatomic Potentials - Parisis, K.; Aifantis, Katerina (Minerals, Metals and Materials Series, 2021)
After a brief review on the ability of continuum gradient elasticity (GradEla) to eliminate singularities from dislocation lines and crack tips, we present an extension to its fractional counterpart by replacing the classical Laplacian in the gradient-enhanced Hooke’s Law by a fractional one. Then, a discussion on implications of fractional gradient elasticity to eliminate stress/strain singularities from a screw dislocation is given, followed by the derivation of the fundamental solution of the governing fractional Helmholtz equation, for addressing more general problems. Finally, an elaboration is provided on using these ideas to revisit interatomic potentials used in materials science simulations.
CRIS-Team Scopus Importer:2021-04-30
Keywords: Fractional laplacian; Gradient elasticity; Interatomic potentials; London modification

Graphene Oxide/Polymer-Based Biomaterials - Ege, Duygu; Kamali, Ali Reza; Boccaccini, Aldo R. (Advanced Engineering Materials, 2017)

Growth Factor-Loaded Mesoporous Silica Particles, Incorporated in Electrospun PCL Fibres, Provide Topographical and Chemical Cues for Tendon Tissue Engineering - Citro, Vera; Clerici, Marta; Shephard, Matthew T.; Dale, Tina P.; Boccaccini, Aldo R.; Forsyth, Nicholas R. (Advanced Materials Technologies, 2025)
This study develops a biomaterial-based strategy to address challenges in controlled growth factor delivery for tenogenic differentiation of mesenchymal stromal cells (MSCs) and tendon stem cells (TSCs). The 20% polycaprolactone (PCL) fibres, electrospun from acetic acid (AA) or formic acid:acetic acid (FA:AA) solutions, are loaded with bovine serum albumin (BSA) to evaluate initial protein-solvent interactions. SEM characterization demonstrated that fibres from AA has larger diameters (391 ± 0.2 nm) than those from FA:AA (282 ± 0.5 nm), with a further increase in diameter upon BSA incorporation. ATR-FTIR analysis confirmed successful protein loading but associated structural changes, particularly in AA fibres. Mesoporous silica nanoparticles (MSNs) are then optimized to encapsulate the model biomolecules BSA, lysozyme, and GDF-7, achieving high encapsulation efficiencies (80–100%) and sustained release due to electrostatic affinity. The MSNs, incorporated into aligned PCL fibres, better protect biomolecule stability and demonstrate uniform distribution, confirmed by SEM-EDS. Functional cell-based assays reveal good cell viability and metabolic activity for MSCs and TSCs cultured on the fibres, further enhanced under physoxic conditions (2% O₂). The scaffold, integrating aligned fibres and MSNs, provides a biomimetic 3D structure for controlled cell alignment and tissue formation. This system offers tuneable drug delivery and shows potential as an autograft alternative for tendon regeneration.
CRIS-Team Scopus Importer:2025-04-25
Keywords: drug delivery system; electrospinning; mesenchymal/stromal stem cells; mesoporous silica nanoparticles; tendon progenitor stem cells; tendon tissue engineering

Growth of hydroxyapatite plate-like nanoparticles by additive free precipitation for the deposition of aligned coatings - Baştan, Fatih E.; Şen, Behlül; Özgenç, Şule; Beltrán, Ana M.; Boccaccini, Aldo R. (Ceramics International, 2023)
In recent years, nanoparticles' morphology has been tailored to tune nanoparticle specific properties for several applications. In particular, plate-like particles have been synthesized to create an analog of nacre microstructure exhibiting outstanding mechanical performance attributed to nacre's micro and nano hierarchy. However, the synthesis of equiaxed hydroxyapatite (HA) plates for constructing an oriented architecture has remained as an astounding challenge. In this study, we designed an additive-free chemical precipitation route in which the pH was increased stepwise to maintain the particles' equiaxed 2d shape. Our results showed that the produced particles exhibited HA's crystal structure and highly sustained the equiaxed/rectangular plate morphology of the octacalcium phosphate (OCP) phase, formed as an interphase during the precipitation. The reaction time, reactant concentration, and heat treatment were found essential in controlling the particles' morphology, size, and crystal symmetry. The crystal features of the particles were dissected via high-resolution scanning and transmission electron microscopes (HRSEM and HRTEM) and X-ray diffraction (XRD) analysis. Moreover, the Williamson-Hall plot and Rietveld Size-strain algorithm were implemented to calculate the crystallite size and strain of the particles. HRSEM and HRTEM micrographs showed that ultrathin (10–20 nm) 2d HA particles with mean lengths of 140–150 nm grew through the c-axis. In the last stage, we attempted to use the particles to deposit oriented coatings by electrophoretic deposition (EPD).
CRIS-Team Scopus Importer:2023-06-23
Keywords: Controlled growth; Plate hydroxyapatite; Size-strain analysis; Willamson-Hall

Guest editorial: GlaCERCo: Glass and ceramic composites for high technology applications - Marie Curie initial training network - Boccaccini, Aldo R.; Ferraris, Monica; Reece, Michael J.; Salvo, Milena (Advances in Applied Ceramics, 2015)

Guest editors’ preface - Boccaccini, Aldo R.; Fenn, Michael; Jones, Julian R.; Kasuga, Toshihiro; Norton, M. Grant; Rahaman, Mohammed N.; Verne, Enrica; Zanotto, Edgar D. (Journal of Materials Science, 2017)
CRIS-Team Scopus Importer:2022-08-05

Hemp Fiber Reinforced Red Mud/Fly Ash Geopolymer Composite Materials: Effect of Fiber Content on Mechanical Strength - Taye, Eyerusalem; Roether, Judith; Schubert, Dirk W.; Redda, Daniel Tilahun; Boccaccini, Aldo R. (Materials, 2021)
Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile.<br
Keywords: hemp fiber; geopolymer composite; mechanical properties; red mud; fly ash; microstructural analysis

Hierarchical microchannel architecture in chitosan/bioactive glass scaffolds via electrophoretic deposition positive-replica - Ghalayani Esfahani, Arash; Soleimanzade, Mehdi; Campiglio, Chiara Emma; Federici, Angelica; Altomare, Lina; Draghi, Lorenza; Boccaccini, Aldo R.; De Nardo, Luigi (Journal of Biomedical Materials Research Part A, 2019)
One of the main challenges in the design of scaffolds for cortical bone regeneration is mimicking the highly oriented, hierarchical structure of the native tissue in an efficient, simple, and consistent way. As a possible solution to this challenge, positive replica based on electrophoretic deposition (EPD) was here evaluated as a technique to produce organic/inorganic scaffolds with oriented micro-porosities mimicking Haversian canals diameter and spacing. Two different sizes of 45S5 bioactive glass (BG) powders were chosen as inclusions and loaded in a chitosan matrix via EPD on micro-patterned cathodes. Self-standing chitosan scaffolds, with a homogeneous dispersion of BG particles and regularly-oriented micro-channels (ϕ = 380 ± 50 μm, inter-channel spacing = 600 ± 40 μm), were obtained. In vitro analysis in simulated body fluid (SBF) revealed the ability to induce a deposition of a homogenous layer of hydroxyapatite (HA), with Ca/P nucleation reactions appearing kinetically favored by smaller BG particles. Cell interaction with hybrid scaffolds was evaluated in vitro with bone osteosarcoma cells (SAOS-2). The osteoconductive potential of EPD structures was assessed by evaluating cells proliferation, viability and scaffold colonization. Results indicate that EPD is a simple yet extremely effective technique to prepare composite micro-patterned structures and can represent a platform for the development of a new generation of bone scaffolds. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.
CRIS-Team Scopus Importer:2019-05-07
Keywords: bioactive glass 45S5; bone regeneration; chitosan; electrophoretic deposition (EPD); micro-structured hybrid scaffolds

Hierarchical multi-layered scaffolds based on electrofluidodynamic processes for tissue engineering - Piegat, Agnieszka; Niemczyk, Agata; Boccaccini, Aldo R.; El Fray, Miroslawa; Liverani, Liliana (Biomedical Materials, 2021)
The aim of this study was to obtain hierarchical scaffolds combining 3D printing and two electrofluidodynamic methods. The multi-layered scaffold is composed by 3D printed struts, electrospun fibers obtained from poly(epsilon-caprolactone) and electrosprayed spheres produced from hydrophobically modified chitosan, namely chitosan grafted with linoleic acid (CHLA). Since CHLA has been used for the first time in the electrospraying (electro dynamic spraying, EDS) process, the formation of spheres needed an optimization process. The EDS process was strongly affected by the solvent mixture composition, concentration of acid used for CHLA dissolution and solution flow rate. By using the optimized electrospraying conditions, uniformly distributed spheres have been obtained, decorating struts and nanofibers. Preliminary biological tests with mouse preosteoblasts (MC3T3-E1) were performed to investigate the effect of the hierarchical scaffold on cell seeding efficacy. Results showed that the hierarchical structure enhances cell seeding efficacy, respect to the 3D printed struts alone, preventing that the cells passed through the struts during the seeding. Moreover, the addition of the electrosprayed nanoparticles does not affect the cell seeding efficiency. The versatility of the proposed structure, with the added value of CHLA nanoparticles decoration could be suitable for several applications in tissue engineering, mainly related to drug delivery systems.
CRIS-Team WoS Importer:2021-04-02

Highly dispersed lithium doped mesoporous silica nanospheres regulating adhesion, proliferation, morphology, ALP activity and osteogenesis related gene expressions of BMSCs. - Zhang, Jue; Cai, Liang; Tang, Liangchen; Zhang, Xiaochen; Yang, Lili; Zheng, Kai; He, Axiang; Boccaccini, Aldo R.; Wei, Jie; Zhao, Jun (Colloids and Surfaces B-Biointerfaces, 2018)
Lithium (Li) doped mesoporous silica nanospheres (LMSNs) were synthesized by incorporation of 5 wt% Li into mesoporous silica nanospheres (MSNs) using sol-gel method. The results showed that LMSNs with a mean size of approximate 300 nm exhibited uniform and highly dispersed spherical morphology, which was similar to the morphology of MSNs. Moreover, the degradability of MSNs was significantly increased after the incorporation of Li, and LMSNs could release both silicon (Si) and Li ions in a sustained manner. Due to the release of Li ions, LMSNs showed higher stimulatory effects on the attachment and proliferation of bone marrow mesenchymal stem cells (BMSCs) than MSNs. In addition, LMSNs could also enhance the ALP activity of BMSCs as well as improving osteogenesis related genes (OPN, ALP, Runx2 and OCN) expression of BMSCs. In summary, LMSNs have shown the capability of being a carrier of biologically active ions, which exhibit great potential in bone repair/regeneration applications.

Highly elastomeric poly(3-hydroxyoctanoate) based natural polymer composite for enhanced keratinocyte regeneration - Rai, Ranjana; Roether, Judith; Knowles, Jonathan C.; Mordan, Nicola; Salih, Vehid; Locke, Ian C.; Gordge, Michael P.; McCormick, Aine; Mohn, Dirk; Stark, Wendelin J.; Keshavarz, Tajalli; Boccaccini, Aldo R.; et al. (International Journal of Polymeric Materials and Polymeric Biomaterials, 2017)
Keywords: Bioactive glass; composites; poly(3-hydroxyoctanoate); skin tissue engineering; wound healing

Highly permeable innovative PDMS coated polyethersulfone membranes embedded with activated carbon for gas separation - Haider, Bilal; Dilshad, Muhammad Rizwan; Ur Rehman, Muhammad Atiq; Akram, Muhammad Sarfraz; Kaspereit, Malte (Journal of Natural Gas Science and Engineering, 2020)
Innovative asymmetric polyethersulfone (PES) membranes embedded with activated carbon (AC) were synthesized and then surface coated with thin PDMS layer. The membranes were then tested with advanced analytical techniques like FTIR, TGA, SEM and EDX analysis. Thereafter, the membranes were tested for gas permeation analysis with following five gases: carbon dioxide, hydrogen, nitrogen, helium and methane. The effects of embedding AC and feed gas pressure on gas permeation properties were also examined. The permeance of all the gases improved with the embedding of AC in the membrane without much decreasing their ideal selectivity while PDMS coating enhanced the ideal selectivity at the expense of decreasing permeance of all the gases. It was found that 30 wt. % AC embedded PDMS coated PES membrane, having thickness of 80 μm, exhibited the best gas permeation properties for following five pair of gases CO2/N2, CO2/CH4, H2/N2, He/N2 and He/CH4 at 25 °C and 20 bar. The best performing membrane was also tested for long term stability by exposing it with each gas for 96 h. It was also found that the performance of 30 wt % AC embedded membrane, surpassed the 2008 Robeson trade off line for all pair of gases except for CO2/CH4 for which it nearly touched this line. Finally, PDMS coated membranes were also tested with CO2/CH4 (50:50) mixture at high pressure and found that mixed gas permeation properties are considerably lesser than pure gas permeation properties due to possibility of competitive sorption phenomenon between the gases.
CRIS-Team Scopus Importer:2020-07-31
Keywords: Activated carbon; Gas separation membranes; PDMS coating; Polyethersulfone

Highly permeable novel PDMS coated asymmetric polyethersulfone membranes loaded with SAPO-34 zeolite for carbon dioxide separation - Haider, Bilal; Dilshad, Muhammad Rizwan; Ur Rehman, Muhammad Atiq; Vargas Schmitz, Jürgen; Kaspereit, Malte (Separation and Purification Technology, 2020)
Novel asymmetric polyethersulfone membranes loaded with SAPO-34 particles were prepared using phase inversion technique and then surface coated with PDMS using spin coating method. The mixed matrix membranes were then characterized by FTIR, TGA, SEM-EDX and gas permeation analysis. Effect of SAPO-34 loading alongwith operating pressure was also analyzed on gas permeation properties of both coated and uncoated membranes. SAPO-34 loading resulted in improvement of permeability of all the gases without much decrease in CO2 ideal selectivity with respect to methane and nitrogen whereas PDMS coating resulted in improvement of ideal selectivity of CO2 at the expense of decrease of permeance of all the gases. It was found that PDMS coated PES membrane, loaded with 30 wt.% SAPO-34, having thickness of 45 µm, demonstrated high CO2 permeance of 641.77 GPU, CO2/CH4 ideal selectivity of 4.45 and CO2/N2 ideal selectivity of 12.45, respectively at 20 bar and 25 °C. It was found that the performance of this membrane crossed the Robeson upper bound limit 2008 for CO2/N2 separation whereas for CO2/CH4 separation it crossed the previous upper bound limit 1991. Finally, the performance of this membrane was also analyzed under mixed gas conditions for CO2/CH4 separation at high pressure.
CRIS-Team Scopus Importer:2020-05-22
Keywords: Asymmetric; Gas separation membranes; PDMS coating; Polyethersulfone; SAPO-34

Highly porous polymer-derived bioceramics based on a complex hardystonite solid solution - Elsayed, Hamada; Secco, Michele; Zorzi, Federico; Schuhladen, Katharina; Detsch, Rainer; Boccaccini, Aldo R.; Bernardo, Enrico (Materials, 2019)
Highly porous bioceramics, based on a complex hardystonite solid solution, were developed fromsilicone resins and micro-sized oxide fillers fired in air at 950 °C. Besides CaO, SrO, MgO, and ZnO precursors, and the commercial embedded silicone resins, calcium borate was essential in providing the liquid phase upon firing and favouring the formation of an unprecedented hardystonite solid solution, corresponding to the formula (Ca0.70Sr0.30)2(Zn0.72Mg0.15Si0.13) (Si0.85B0.15)2O7. Silicone-filler mixtures could be used in the form of thick pastes for direct ink writing of reticulated scaffolds or for direct foaming. The latter shaping option benefited from the use of hydrated calcium borate, which underwent dehydration, with water vapour release, at a low temperature (420 °C). Both scaffolds and foams confirmed the already-obtained phase assemblage, after firing, and exhibited remarkable strength-to-density ratios. Finally, preliminary cell tests excluded any cytotoxicity that could be derived from the formation of a boro-silicate glassy phase.
CRIS-Team Scopus Importer:2019-12-13
Keywords: 3D printed scaffolds; Biosilicate ceramics; Direct ink writing (DIW); Foams; Hardystonite; Polymer derived ceramics (PDCs)

High-resolution synchrotron X-ray analysis of bioglass-enriched hydrogels - Gorodzha, Svetlana; Douglas, Timothy E L; Samal, Sangram K.; Detsch, Rainer; Cholewa-Kowalska, Katarzyna; Braeckmans, Kevin; Boccaccini, Aldo R.; Skirtach, Andre G.; Weinhardt, Venera; Baumbach, Tilo; Surmeneva, Maria A.; Surmenev, Roman A. (Journal of Biomedical Materials Research Part A, 2016)
Enrichment of hydrogels with inorganic particles improves their suitability for bone regeneration by enhancing their mechanical properties, mineralizability, and bioactivity as well as adhesion, proliferation, and differentiation of bone-forming cells, while maintaining injectability. Low aggregation and homogeneous distribution maximize particle surface area, promoting mineralization, cell-particle interactions, and homogenous tissue regeneration. Hence, determination of the size and distribution of particles/particle agglomerates in the hydrogel is desirable. Commonly used techniques have drawbacks. High-resolution techniques (e.g., SEM) require drying. Distribution in the dry state is not representative of the wet state. Techniques in the wet state (histology, μCT) are of lower resolution. Here, self-gelling, injectable composites of Gellan Gum (GG) hydrogel and two different types of sol-gel-derived bioactive glass (bioglass) particles were analyzed in the wet state using Synchrotron X-ray radiation, enabling high-resolution determination of particle size and spatial distribution. The lower detection limit volume was 9 × 10 mm. Bioglass particle suspensions were also studied using zeta potential measurements and Coulter analysis. Aggregation of bioglass particles in the GG hydrogels occurred and aggregate distribution was inhomogeneous. Bioglass promoted attachment of rat mesenchymal stem cells (rMSC) and mineralization.
Keywords: Bioglass; Composite; Hydrogel; Particle; X-ray

Hot-pressed phosphate glass-ceramic matrix composites containing calcium phosphate particles for nuclear waste encapsulation - Michie, E. M.; Grimes, R. W.; Boccaccini, Aldo R. (Journal of Materials Science, 2008)
Sodium aluminium phosphate (NaAlP) glass-ceramic composites were produced as potential wasteforms for the immobilization of special categories of halide-containing radioactive waste. Sintering conditions for encapsulating a simulated waste (a calcinated mixture of calcium phosphate host and various oxides) in the cold-pressed NaAlP glass-ceramic were first determined and the results were compared with similar samples prepared by hot pressing. In both cases, the conditions aimed to provide a very high-density material, via as low production temperatures as possible, in conjunction with a high waste loading (75 wt.% simulated waste to 25 wt.% glass). It was found that by hot pressing and using a NaAlP glass-ceramic containing 2 mol% B2O3, significantly lower temperatures could be employed compared to the cold pressing and sintering route. The lowest temperature at which a sufficiently dense hot-pressed product was achieved (86% theoretical density), that exhibited mechanical properties similar to those of borosilicate glass (e.g. Young's modulus 67 ± 2 GPa), was 550 °C. This processing temperature is considerably lower than values reported in the literature for similar systems. As such, hot pressing can be considered as a convenient technique for the fabrication of this type of composite for waste encapsulation. © 2008 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.hotpre

How degradation of calcium phosphate bone substitute materials is influenced by phase composition and porosity - Schaefer, S.; Detsch, Rainer; Uhl, Franziska Elisabeth; Deisinger, U.; Ziegler, G. (Advanced Engineering Materials, 2011)
The chemical composition of calcium phosphate (CaP) materials for the regenerative therapy of large bone defects is similar to that of bone. Additionally, calcium phosphates show an excellent biocompatibility. Besides the support of defect healing calcium phosphate implants should be completely degraded within an adequate time period to be replaced by newly formed bone. Although degradation of CaP-implants occurs mainly by dissolution of the material, it is important to characterize the osteoclastic resorption as well, which is involved in native bone remodeling. The degradation of bone substitutes made of calcium phosphate ceramics is influenced by various parameters, such as defect size and localization, the general health situation, and age of the patient, but also material properties are important. Especially, the calcium phosphate composition is crucial for the degradation behavior of a calcium phosphate material. Additionally, at the cellular level the micro- and macroporosity, including interconnecting pores, influences both, the dissolution and the osteoclastic resorption. In our study, three different calcium phosphate materials (hydroxyapatite, tricalcium phosphate, and a biphasic calcium phosphate) and two different geometries (dense 2D samples and porous 3D scaffolds) are compared regarding their dissolution and resorption behavior. The results show, that the dissolution of CaP-ceramics, as examined by the incubation in a degradation solution, depends mainly on the calcium phosphate phase but also on the porosity of the implant. Regarding the resorption, cell proliferation and differentiation of a monocytic cell line as well as the formation of resorption lacunas are analyzed. Cell proliferation is comparable on all phase compositions. Cell differentiation and resorption, however, are influenced by the calcium phosphate phase composition and by the implant porosity as well. By understanding these two mechanisms of degradation, bone substitute materials and, as a result, the bone regeneration of large bone defects using CaP-ceramics can be improved. Degradation of synthetic calcium phosphates that are used for bone substitution is defined by both chemical dissolution (physicochemical degradation) and resorption (cellular degradation by osteoclasts). In summary, the degradation mechanisms depend on both, the calcium phosphate composition and the sample micro- and macroporosity. Therefore, degradation of a bone substitute can be adjusted in the individual case by both parameters, whereby phase composition has a greater influence than sample porosity. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGa

How to Determine a Suitable Alginate for Biofabrication Approaches using an Extensive Alginate Library? - Karakaya, Emine; Schöbel, Lisa; Zhong, Yu; Hazur, Jonas; Heid, Susanne; Forster, Leonard; Tessmar, Joerg; Boccaccini, Aldo R.; Detsch, Rainer (Biomacromolecules, 2023)
Alginate-based hydrogels are a promising class of biomaterials due to their usability, biocompatibility, and high water -binding capacity which is the reason for their broad use in biofabrication. One challenge of these biomaterials is, however, the lack of cell adhesion motifs. This drawback can be overcome by oxidizing alginate to alginate dialdehyde (ADA) and by subsequent cross-linking with gelatin (GEL) to fabricate ADA-GEL hydrogels, which offer improved cell-material interactions. The present work investigates four pharmaceutical grade alginates of different algae sources and their respective oxidized forms regarding their molecular weight and M/G ratio using 1H NMR spectroscopy and gel permeation chromatography. In addition, three different methods for determining the degree of oxidation (% DO) of ADA, including iodometric, spectroscopic, and titration methods, are applied and compared. Furthermore, the aforementioned properties are correlated with the resulting viscosity, degradation behavior, and cell-material interactions to predict the material behavior in vitro and thus choose a suitable alginate for an intended application in biofabrication. In the framework of the present work, easy and practicable detection methods for the investigations of alginate-based bioinks were summarized and shown. In this regard, the success of oxidation of alginate was confirmed by the three aforementioned methods and was further proven by solid-state 13C NMR, for the first time in the literature, that only guluronic acid (G) was attacked during the oxidation, leading to the formation of hemiacetals. Furthermore, it was shown that ADA-GEL hydrogels of alginates with longer G-blocks are more suitable for long-term experiments due to their stability over an incubation period of 21 days, while ADA-GEL hydrogels of alginates with longer mannuronic acid (M)-blocks are more suitable for short-term applications such as sacrificial inks due to their extensive swelling and subsequent loss of shape. Finally, it was proven that the M/G ratio did not show any influence on the biocompatibility or printability of the investigated alginate-based hydrogels. The physicochemical findings provide an alginate library for tailored application in biofabrication.
CRIS-Team WoS Importer:2023-05-05

Human Induced Pluripotent Stem Cell-Derived Neural Progenitor Cells Produce Distinct Neural 3D In Vitro Models Depending on Alginate/Gellan Gum/Laminin Hydrogel Blend Properties - Kapr, Julia; Petersilie, Laura; Distler, Thomas; Lauria, Ines; Bendt, Farina; Sauter, Clemens M.; Boccaccini, Aldo R.; Rose, Christine R.; Fritsche, Ellen (Advanced Healthcare Materials, 2021)
Stable and predictive neural cell culture models are a necessary premise for many research fields. However, conventional 2D models lack 3D cell-material/-cell interactions and hence do not reflect the complexity of the in vivo situation properly. Here two alginate/gellan gum/laminin (ALG/GG/LAM) hydrogel blends are presented for the fabrication of human induced pluripotent stem cell (hiPSC)-based 3D neural models. For hydrogel embedding, hiPSC-derived neural progenitor cells (hiNPCs) are used either directly or after 3D neural pre-differentiation. It is shown that stiffness and stress relaxation of the gel blends, as well as the cell differentiation strategy influence 3D model development. The embedded hiNPCs differentiate into neurons and astrocytes within the gel blends and display spontaneous intracellular calcium signals. Two fit-for-purpose models valuable for i) applications requiring a high degree of complexity, but less throughput, such as disease modeling and long-term exposure studies and ii) higher throughput applications, such as acute exposures or substance screenings are proposed. Due to their wide range of applications, adjustability, and printing capabilities, the ALG/GG/LAM based 3D neural models are of great potential for 3D neural modeling in the future.
CRIS-Team WoS Importer:2021-07-16

Human nasoseptal chondrocytes maintain their differentiated phenotype on PLLA scaffolds produced by thermally induced phase separation and supplemented with bioactive glass 1393 - Conoscenti, Gioacchino; Pavia, Francesco Carfi; Ongaro, Alfred; Brucato, Valerio; Goegele, Clemens; Schwarz, Silke; Boccaccini, Aldo R.; Stoelzel, Katharina; La Carrubba, Vincenzo; Schulze-Tanzil, Gundula (Connective Tissue Research, 2019)
Damage of hyaline cartilage such as nasoseptal cartilage requires proper reconstruction, which remains challenging due to its low intrinsic repair capacity. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. Despite so far mostly tested for bone tissue engineering, bioactive glass (BG) could exert stimulatory effects on chondrogenesis.The aim of this work was to produce and characterize composite porous poly(L-lactide) (PLLA)/1393BG scaffolds via thermally induced phase separation (TIPS) technique and assess their effects on chondrogenesis of nasoseptal chondrocytes.The PLLA scaffolds without or with 1, 2.5, 5% BG1393 were prepared via TIPS technique starting from a ternary solution (polymer/solvent/non-solvent) in a single step. Scaffolds were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetric analysis (DSC). Human nasoseptal chondrocytes were seeded on the scaffolds with 1 and 2.5% BG for 7 and 14days and cell survival, attachment, morphology and expression of SOX9 and cartilage-specific extracellular cartilage matrix (ECM) components were monitored.The majority of chondrocytes survived on all PLLA scaffolds functionalized with BG for the whole culture period. Also inner parts of the scaffold were colonized by chondrocytes synthesizing an ECM which contained glycosaminoglycans. Type II collagen and aggrecan gene expression increased significantly in 1% BG scaffolds during the culture. Chondrocyte protein expression for cartilage ECM proteins indicated that the chondrocytes maintained their differentiated phenotype in the scaffolds.BG could serve as a cytocompatible basis for future scaffold composites for osteochondral cartilage defect repair.Abbreviations: AB: alcian blue ACAN: gene coding for aggrecan; BG: Bioactive glass; 2D: two-dimensional; 3D: three-dimensional; COL2A1: gene coding for type II collagen; DAPI: 4',6-diamidino-2-phenylindole; DMEM: Dulbecco's Modified Eagle's Medium; DMMB: dimethylmethylene blue; DSC: Differential scanning calorimetric analysis; ECM: extracellular matrix; EDTA: ethylenediaminetetraacetic acid; EtBr: ethidium bromide; FCS: fetal calf serum; FDA: fluorescein diacetate; GAG: glycosaminoglycans; HDPE: high density polyethylene; HE: hematoxylin and eosin staining; HCA: hydoxylapatite; PBE: phosphate buffered EDTA100mM Na2HPO4 and 5mM EDTA, pH8; PBS: phosphate buffered saline; PFA: paraformaldehyde; PG: proteoglycans; PI: propidium iodide; PLLA: Poly-L-Lactic Acid Scaffold; RT: room temperature; SD: standard deviation; SEM: scanning electron microscopy; sGAG: sulfated glycosaminoglycans; SOX9/Sox9: SRY (sex-determining region Y)-box 9 protein; TBS: TRIS buffered saline; TIPS: Thermally Induced Phase Separation; XRD: X-ray diffraction analysis
CRIS-Team WoS Importer:2019-07-09

Hyaluronic Acid-Based Bioink Composition Enabling 3D Bioprinting and Improving Quality of Deposited Cartilaginous Extracellular Matrix - Hauptstein, Julia; Böck, Thomas; Bartolf-Kopp, Michael; Forster, Leonard; Stahlhut, Philipp; Nadernezhad, Ali; Blahetek, Gina; Zernecke-Madsen, Alma; Detsch, Rainer; Jüngst, Tomasz; Groll, Jürgen; Teßmar, Jörg; et al. (Advanced Healthcare Materials, 2020)
In 3D bioprinting, bioinks with high concentrations of polymeric materials are frequently used to enable fabrication of 3D cell-hydrogel constructs with sufficient stability. However, this is often associated with restricted cell bioactivity and an inhomogeneous distribution of newly produced extracellular matrix (ECM). Therefore, this study investigates bioink compositions based on hyaluronic acid (HA), an attractive material for cartilage regeneration, which allow for reduction of polymer content. Thiolated HA and allyl-modified poly(glycidol) in varying concentrations are UV-crosslinked. To adapt bioinks to poly(ε-caprolactone) (PCL)-supported 3D bioprinting, the gels are further supplemented with 1 wt% unmodified high molecular weight HA (hmHA) and chondrogenic differentiation of incorporated human mesenchymal stromal cells is assessed. Strikingly, addition of hmHA to gels with a low polymer content (3 wt%) results in distinct increase of construct quality with a homogeneous ECM distribution throughout the constructs, independent of the printing process. Improved ECM distribution in those constructs is associated with increased construct stiffness after chondrogenic differentiation, as compared to higher concentrated constructs (10 wt%), which only show pericellular matrix deposition. The study contributes to effective bioink development, demonstrating dual function of a supplement enabling PCL-supported bioprinting and at the same time improving biological properties of the resulting constructs.
CRIS-Team Scopus Importer:2020-08-14
Keywords: biofabrication; bioinks; chondrogenic differentiation; extracellular matrix; hyaluronic acid

Hybrid gelatin/oxidized chondroitin sulfate hydrogels incorporating bioactive glass nanoparticles with enhanced mechanical properties, mineralization, and osteogenic differentiation - Zhou, Lei; Fan, Lei; Zhang, Feng Miao; Jiang, Yuhe; Cai, Min; Dai, Cong; Luo, Yi An; Tu, Ling Jie; Zhou, Zheng Nan; Li, Xiao Jun; Ning, Cheng Yun; Zheng, Kai; et al. (Bioactive Materials, 2021)
Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior. However, these hydrogels suffer from low mechanical properties, uncontrolled degradation, and insufficient osteogenic activity, which limits their applications in bone regeneration. In this study, we developed hybrid gelatin (Gel)/oxidized chondroitin sulfate (OCS) hydrogels that incorporated mesoporous bioactive glass nanoparticles (MBGNs) as bioactive fillers for bone regeneration. Gel-OCS hydrogels could be self-crosslinked in situ under physiological conditions in the presence of borax. The incorporation of MBGNs enhanced the crosslinking and accelerated the gelation. The gelation time decreased with increasing the concentration of MBGNs added. Incorporation of MBGNs in the hydrogels significantly improved the mechanical properties in terms of enhanced storage modulus and compressive strength. The injectability of the hydrogels was not significantly affected by the MBGN incorporation. Also, the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro and rat cranial defect restoration in vivo were significantly promoted by the hydrogels in the presence of MBGNs. The hybrid Gel-OCS/MBGN hydrogels show promising potential as injectable biomaterials or scaffolds for bone regeneration/repair applications given their tunable degradation and gelation behavior as well as favorable mechanical behavior and osteogenic activities.
CRIS-Team Scopus Importer:2020-10-23
Keywords: Bioactive glasses; Biopolymers; Bone regeneration; Hybrids; Hydrogels

Hybrid hydrogels based on keratin and alginate for tissue engineering - Silva, Raquel; Singh, Raminder; Sarker, Bapi; Papageorgiou, Dimitrios G.; Juhasz, Judith A.; Roether, Judith; Cicha, Iwona; Kaschta, Joachim; Schubert, Dirk W.; Chrissafis, Konstantinos; Detsch, Rainer; Boccaccini, Aldo R. (Journal of Materials Chemistry B, 2014)
Novel hybrid hydrogels based on alginate and keratin were successfully produced for the first time. The self-assembly properties of keratin, and its ability to mimic the extracellular matrix were combined with the excellent chemical and mechanical stability and biocompatibility of alginate to produce 2D and 3D hybrid hydrogels. These hybrid hydrogels were prepared using two different approaches: sonication, to obtain 2D hydrogels, and a pressure-driven extrusion technique to produce 3D hydrogels. All results indicated that the composition of the hydrogels had a significant effect on their physical properties, and that they can easily be tuned to obtain materials suitable for biological applications. The cell-material interaction was assessed through the use of human umbilical vein endothelial cells, and the results demonstrated that the alginate/keratin hybrid biomaterials supported cell attachment, spreading and proliferation. The results proved that such novel hybrid hydrogels might find applications as scaffolds for soft tissue regeneration. © 2014 the Partner Organisations.

Hybrid particles derived from alendronate and bioactive glass for treatment of osteoporotic bone defects - Diba, Mani; Camargo, Winston A.; Zinkevich, Tatiana; Grünewald, Alina; Detsch, Rainer; Kabiri, Yoones; Kentgens, Arno P. M.; Boccaccini, Aldo R.; Van Den Beucken, Jeroen J. J. P.; Leeuwenburgh, Sander C. G. (Journal of Materials Chemistry B, 2019)
Osteoporosis is the most widespread metabolic bone disease which represents a major public health burden. Consequently, novel biomaterials with a strong capacity to regenerate osteoporotic bone defects are urgently required. In view of the anti-osteoporotic and osteopromotive efficacy of alendronate and 45S5 bioactive glass, respectively, we investigated the feasibility to synthesize novel hybrid particles by exploiting the strong interactions between these two compounds. Herein, we demonstrate the facile preparation of a novel class of hybrid particles of tunable morphology, chemical composition and structure. These hybrid particles (i) release alendronate and various inorganic elements (Ca, Na, Si, and P) in a controlled manner, (ii) exhibit a strong anti-osteoclastic effect in vitro, and (iii) stimulate regeneration of osteoporotic bone in vivo. Consequently, this novel class of hybrid biomaterials opens up new avenues of research on the design of bone substitutes with specific activity to facilitate regeneration of bone defects in osteoporotic patients.
CRIS-Team Scopus Importer:2019-07-19

Hybrids Part A: Hybrids for Tissue Regeneration - Zheng, Kai; Salinas, Antonio Jesus; Lao, Jonathan (Frontiers in Bioengineering and Biotechnology, 2021)
CRIS-Team Scopus Importer:2021-09-17
Keywords: bone regeneration; hybrids; periodontal tissue regeneration; scaffolds; wound healing

Hydrogel films and microcapsules based on soy protein isolate combined with alginate - Tansaz, Samira; Durmann, Ann-Katrin; Detsch, Rainer; Boccaccini, Aldo R. (Journal of Applied Polymer Science, 2016)
Alginate hydrogels are combined with soy protein isolate (SPI), a plant derived protein with low immunogenicity, appropriate biodegradability and low cost, to produce biocompatible films, and microcapsules. The cell–material interaction is assessed through the use of mouse embryotic fibroblast cells (MEF cells) on films, and the results illustrate that the alginate/SPI hydrogel films support cell attachment, spreading, and proliferation. Cell biology results combined with degradation studies suggest that such hydrogels are promising biomaterials for soft tissue regeneration or as wound dressing materials.
Keywords: alginate; biomedical applications; hydrogels; soy protein isolate

Hydrogel-inorganic filler composites for 3D bioprinting - Bider, Faina; Boccaccini, Aldo R. (Elsevier, 2023)
Three-dimensional (3D) bioprinting technologies provide opportunities to create cell-laden complex scaffolds for tissue engineering. Hydrogels are the materials of choice for 3D bioprinting applications due to their capability to encapsulate cells in a water-rich environment. Their structure is similar to the one of the natural extracellular matrix. However, standard hydrogels possess usually low mechanical properties and lack adequate functionalities, which can be overcome through the development of multimaterial systems, for example, by incorporation of inorganic fillers. Addition of inorganic fillers, such as hydroxyapatite, nanoclays, bioactive glass (nano)particles and carbonaceous nanomaterials usually results in improved printability of 3D scaffolds due to the possibility to adjust the viscosity and to enhance the mechanical properties of the composite hydrogels. In addition, inorganic fillers provide novel biological functionalities to the hydrogel matrix. The following book chapter gives an outline of the combinations of hydrogels with inorganic fillers, both biodegradable and persistent fillers, including also anisotropic fillers, which are being developed for 13D-bioprinting applications.
CRIS-Team Scopus Importer:2023-11-24
Keywords: 3D bioprinting; bioactive glasses; biofabrication; bioinks; composites; Hydrogels; inorganic filler

Hydrogel matrices based on elastin and alginate for tissue engineering applications - Silva, Raquel; Singh, Raminder; Sarker, Bapi; Papageorgiou, Dimitrios G.; Juhasz-Bortuzzo, Judith A.; Roether, Judith; Cicha, Iwona; Kaschta, Joachim; Schubert, Dirk W.; Chrissafis, Konstantinos; Detsch, Rainer; Boccaccini, Aldo R. (International Journal of Biological Macromolecules, 2018)
Hydrogels from natural polymers are widely used in tissue engineering due to their unique properties, especially when regarding the cell environment and their morphological similarity to the extracellular matrix (ECM) of native tissues. In this study, we describe the production and characterization of novel hybrid hydrogels composed of alginate blended with elastin from bovine neck ligament. The properties of elastin as a component of the native ECM were combined with the excellent chemical and mechanical stability as well as biocompatibility of alginate to produce two hybrid hydrogels geometries, namely 2D films obtained using sonication treatment and 3D microcapsules produced by pressure-driven extrusion. The resulting blend hydrogels were submitted to an extensive physico-chemical characterization. Furthermore, the biological compatibility of these materials was assessed using normal human dermal fibroblasts, indicating the suitability of this blend for soft tissue engineering. (C) 2018 Elsevier B.V. All rights reserved.
Keywords: Alginate; Elastin; Hybrid hydrogels; Soft matrices; Tissue engineering

Hydroxyapatite-Coated SPIONs and Their Influence on Cytokine Release - Friedrich, Bernhard; Auger, Jean-Philippe; Dutz, Silvio; Cicha, Iwona; Schreiber, Eveline; Band, Julia; Boccaccini, Aldo R.; Krönke, Gerhard; Alexiou, Christoph; Tietze, Rainer (International Journal of Molecular Sciences, 2021)
Hydroxyapatite- or calcium phosphate-coated iron oxide nanoparticles have a high potential for use in many biomedical applications. In this study, a co-precipitation method for the synthesis of hydroxyapatite-coated nanoparticles (SPIONHAp), was used. The produced nanoparticles have been characterized by dynamic light scattering, X-ray diffraction, vibrating sample magnetometry, Fourier transform infrared spectrometry, atomic emission spectroscopy, scanning electron microscopy, transmission electron microscopy, selected area diffraction, and energy-dispersive X-ray spectroscopy. The results showed a successful synthesis of 190 nm sized particles and their stable coating, resulting in SPIONHAp. Potential cytotoxic effects of SPIONHAp on EL4, THP-1, and Jurkat cells were tested, showing only a minor effect on cell viability at the highest tested concentration (400 mu g Fe/mL). The results further showed that hydroxyapatite-coated SPIONs can induce minor TNF-alpha and IL-6 release by murine macrophages at a concentration of 100 mu g Fe/mL. To investigate if and how such particles interact with other substances that modulate the immune response, SPIONHAp-treated macrophages were incubated with LPS (lipopolysaccharides) and dexamethasone. We found that cytokine release in response to these potent pro- and anti-inflammatory agents was modulated in the presence of SPIONHAp. Knowledge of this behavior is important for the management of inflammatory processes following in vivo applications of this type of SPIONs.
CRIS-Team WoS Importer:2021-05-14

Hydroxyapatite Coatings on Titanium Alloy TNTZ using Electrophoretic Deposition - Gunawarman,; Nuswantoro, N. F.; Juliadmi, Dian; Fajri, H.; Budiman, A.; Tjong, D. H.; Manjas, M. (IOP Conference Series: Materials Science and Engineering, 2019)
TNTZ is a β-type titanium alloy that designed for orthopedic implant application. This material has superiority in mechanical properties such as high strength to work on load bearing or dynamic bearing, elasticity that is close to the human bone, contained non-toxic materials, and biocompatible. However, the inertness of titanium made this material still have no bioactivity, so that it cannot trigger the bone tissue to grow faster and produce optimum osseointegration. Hydroxyapatite (HA) has chosen as the coating material for TNTZ since the biocompatibility and bioactivity of this ceramic material. So that, by combining mechanical properties of TNTZ and bioactivity of HA it can be expected that better orthopedic implant would be produced. Electrophoretic Deposition (EPD) has chosen as the coating method since the simplicity of the making, relatively low cost, and the ability to coat things with complicated design. In this method, electrical current is used trough cathode and anode within the HA suspension. The electrical potential (voltage) will transport the small particle of HA to be deposited on the surface of TNTZ until producing an even layer of HA coating. This coating process requires two major parameters that are voltage and coating times. The desired quality of HA coating that would produce can be achieved by adjusting these parameters. Voltages are in the range of 7, 10, and 13 volts while coating times are in the range of 7, 10, and 13 minutes. Based on the result it is known that the best HA coating that can be produced are on 10 minutes and 10 volts. This best result shows the good surface morphology, optimum value of mass growth, coating thickness, and surface coverage. Based on this research it can be concluded that increasing voltage and coating times will increase the coating thickness and surface coverage of HA coating. This result shows that the EPD can be used to produce TNTZ titanium implant that coated with HA for orthopedic application.
CRIS-Team Scopus Importer:2019-10-22

Hydroxyapatite/sodium alginate coatings electrophoretically deposited on titanium substrates: microstructure and properties - Moskalewicz, Tomasz; Warcaba, Maciej; Cieniek, Łukasz; Sitarz, Maciej; Gajewska, Marta; Boccaccini, Aldo R. (Applied Surface Science, 2021)
The aim of the present work was to develop the electrophoretic deposition (EPD) of composite bioinspired hydroxyapatite/sodium alginate (HA/SA) coatings on titanium and coatings characterization. The EPD was performed from water-based suspensions with different content of HA. The influence of the EPD parameters on the coating homogeneity, morphology and properties are discussed. Depending on the HA content in suspension, it was possible to obtain dense coatings with different amounts and sizes of HA agglomerates, exhibiting different surface morphology. The state of preparation of the substrate surface and the HA content in suspension significantly affects the coating adhesion. All composite coatings had better adhesion to chemically treated titanium in comparison with the adhesion of pure SA coatings. Strong variations of coating microstructure were observed depending on the HA content and suspension pH due to a cross-linking process between HA and SA. All coatings, regardless of the HA content revealed hydrophilic character. HA/SA coatings exhibited about 10% higher values of surface free energy than the pure SA ones. This work confirmed that EPD is a useful technique to co-deposit HA nanoparticles and SA to fabricate a wide range of coatings with tailored microstructure and surface morphology with potential for biomedical applications.
CRIS-Team Scopus Importer:2020-11-27
Keywords: Bioinspired coatings; Electrophoretic deposition; Hydroxyapatite; Sodium alginate; Titanium

Hydroxycarbonate apatite formation, cytotoxicity, and antibacterial properties of rubidium-doped mesoporous bioactive glass nanoparticles - Pantulap, Usanee; Ünalan, Irem; Zheng, Kai; Boccaccini, Aldo R. (Journal of Porous Materials, 2024)
Rubidium (Rb) has been shown to impact biological activity. This work synthesized Rb-doped mesoporous bioactive glass nanoparticles (MBGNs) based on the composition 70SiO2–30CaO mol% with a sol-gel method. Rb2O was substituted for CaO in concentrations of 5 and 10 mol%. The influence of Rb incorporation on the hydroxycarbonate apatite (HCA) formation, cytotoxicity, and antibacterial capacity of particles was evaluated. XRD analysis confirmed the amorphous structure of the particles. In vitro, biomineralization studies showed HCA on the surface of MBGN and Rb-doped MBGN pellets after 7 days of soaking in simulated body fluid (SBF). An inhibition zone of Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) around Rb-doped MBGN pellets was detected, while MBGN pellets did not show any inhibition zone. Additionally, MC3T3-E1 pre-osteoblastic cells demonstrated cytocompatibility when exposed to Rb-MBG suspensions at different concentrations of up to 250 µg/ml. Based on their overall properties, Rb-containing MBGNs are proposed for biomedical applications, such as filler nanoparticles in composite bone scaffolds.
CRIS-Team Scopus Importer:2024-03-15
Keywords: Bioactive glass; Mesoporous; Nanoparticle; Rubidium; Sol-gel method

Hyperelastic parameter identification of human articular cartilage and substitute materials - Weizel, A.; Distler, Thomas; Detsch, Rainer; Boccaccini, Aldo R.; Paulsen, Friedrich; Seitz, H.; Budday, Silvia; Bräuer, Lars (Journal of the Mechanical Behavior of Biomedical Materials, 2022)
Numerical simulations are a valuable tool in the field of tissue engineering for cartilage repair and can help to understand which mechanical properties affect the behavior of chondrocytes and contribute to the success or failure of surrogate materials as implants. However, special attention needs to be paid when identifying corresponding material parameters in order to provide reliable numerical predictions of the material's response. In this study, we identify hyperelastic material parameters for numerical simulations in COMSOL Multiphysics (R) v. 5.6 for human articular cartilage and two surrogate materials, commercially available ChondroFiller(liquid), and oxidized alginate-gelatin (ADA-GEL) hydrogels. We consider several hyperelastic isotropic material models and provide separate parameter sets for the unconditioned and the conditioned material response, respectively, based on previously generated experimental data including both compression and tension experiments. We compare a direct parameter identification approach assuming homogeneous deformation throughout the specimen and an inverse approach, where the experiments are simulated using a finite element model with realistic boundary conditions in COMSOL Multiphysics (R) v. 5.6. We demonstrate that it is important to consider both compression and tension data simultaneously and to use the inverse approach to obtain reliable parameters. The one-term Ogden model best represents the unconditioned response of cartilage, while the conditioned response of cartilage and ADA-GEL is equally well represented by the two-term Ogden and five-term Mooney-Rivlin models. The five-term Mooney-Rivlin model is also most suitable to model the unconditioned response of ADA-GEL. For ChondroFiller(liquid), we suggest using the five-term Mooney-Rivlin or two-term Ogden model for the unconditioned and the two-term Ogden model for the conditioned material response. These results will help to choose appropriate material models and parameters for simulations of whole joints or to advance mechanical-stimulation assisted cartilage tissue engineering in the future.
CRIS-Team WoS Importer:2022-07-01
Keywords: Parameter identification; Finite hyperelasticity; Human articular cartilage; Hydrogels; Tissue engineering

Hypericin-bearing magnetic iron oxide nanoparticles for selective drug delivery in photodynamic therapy - Unterweger, Harald; Subatzus, Daniel; Tietze, Rainer; Janko, Christina; Poettler, Marina; Stiegelschmitt, Alfons; Schuster, Matthias; Maake, Caroline; Boccaccini, Aldo R.; Alexiou, Christoph (International Journal of Nanomedicine, 2015)
Combining the concept of magnetic drug targeting and photodynamic therapy is a promising approach for the treatment of cancer. A high selectivity as well as significant fewer side effects can be achieved by this method, since the therapeutic treatment only takes place in the area where accumulation of the particles by an external electromagnet and radiation by a laser system overlap. In this article, a novel hypericin-bearing drug delivery system has been developed by synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) with a hypericin-linked functionalized dextran coating. For that, sterically stabilized dextran-coated SPIONs were produced by coprecipitation and crosslinking with epichlorohydrin to enhance stability. Carboxymethylation of the dextran shell provided a functionalized platform for linking hypericin via glutaraldehyde. Particle sizes obtained by dynamic light scattering were in a range of 55-85 nm, whereas investigation of single magnetite or maghemite particle diameter was performed by transmission electron microscopy and X-ray diffraction and resulted in approximately 4.5-5.0 nm. Surface chemistry of those particles was evaluated by Fourier transform infrared spectroscopy and ζ potential measurements, indicating successful functionalization and dispersal stabilization due to a mixture of steric and electrostatic repulsion. Flow cytometry revealed no toxicity of pure nanoparticles as well as hypericin without exposure to light on Jurkat T-cells, whereas the combination of hypericin, alone or loaded on particles, with light-induced cell death in a concentration and exposure time-dependent manner due to the generation of reactive oxygen species. In conclusion, the combination of SPIONs’ targeting abilities with hypericin’s phototoxic properties represents a promising approach for merging magnetic drug targeting with photodynamic therapy for the treatment of cancer.
Keywords: Hypericin; Magnetic drug targeting; Photodynamic therapy; SPION

Identification of Process Limits for Electro-Spinning of aligned – Nano Fibres of the CPL/PGS 1: 1 blend - Bischoff, S.; Küng, Florian; Stafiej, Piotr; Fuchsluger, Thomas; Boccaccini, Aldo R.; Schubert, Dirk W. (14th Bayreuth Polymer Symposium, 2015)

Identifying key processing parameters for the electrospinning of aligned polymer nanofibers - Dörgens, Anna; Roether, Judith; Dippold, Dirk; Boccaccini, Aldo R.; Schubert, Dirk W. (Materials Letters, 2015)
Aligned polycaprolactone (PCL) fibers of interest for numerous applications requiring contact guidance and textured topography were fabricated by electrospinning onto a rotating collector using tangential velocities ranging from 0 m/s to 11 m/s. The deposition characteristics of the fibers were investigated by microscopic methods to gather information about fiber diameter, collection angle theta, and number of fibers per reference length. It was shown that the deposition angle ranged from -2.0 degrees to 1.6 degrees and the diameter of the developed fibers averaged 587 nm to 878 nm. Furthermore the deposition angle was found to be independent of die rotation velocity. Homogeneity of the fiber mats was improved with increasing rotation velocity. The number of fibers per reference length, a measure for collection.efficiency, proved to be dependent on the rotation velocity, following a modified Weibull function. Hence the collection efficiency of the process can be improved by increasing the rotation velocity above a critical value. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Electrospinning; Fiber alignment; Polymers; Fiber technology; Porous materials

Identifying predictors of treatment response in major depressive disorder: A machine learning approach - Amir, Fattahi; Schrauder, Michael (Revista De Psiquiatria Clinica, 2023)
The essential purpose of research study is determining the predictors related to treatment response in the major depressive d isorder. This research study also represents that machine learning approach between them for analysis. The research based on secondary data analysis for this purpose used different websites related to the variables. the treatment response predictors are main independent variable the depressive disorder is main dependent variable. for measuring the research study used E-views software and generate informative results. The descriptive statistical analysis, the unit root test analysis, the equality test analysis, also that present the co-integration analysis between them. the overall results founded that direct and significant link of predictors of treatment response in the major depressive disorder.
CRIS-Team Scopus Importer:2023-10-06
Keywords: depressive Disorder (DD); E-views software; machine Learning Approach (MLA); Predictors of Treatment response (PTR)

Immunomodulatory bioactive glasses for tissue regeneration - Zheng, Kai; Niu, Wen; Lei, Bo; Boccaccini, Aldo R. (Acta Biomaterialia, 2021)
The regulatory functions of the immune response in tissue healing, repair, and regeneration have been evidenced in the last decade. Immune cells play central roles in immune responses toward inducing favorable tissue regenerative processes. Modulating and controlling the immune cell responses (particularly macrophages) is an emerging approach to enhance tissue regeneration. Bioactive glasses (BGs) are multifunctional materials exhibiting osteogenic, angiogenic, and antibacterial properties, being increasingly investigated for various tissue regeneration scenarios, including bone regeneration and wound healing. On the other hand, the immunomodulatory effects of BGs in relation to regenerating tissues have started to be understood, and key knowledge is emerging. This is the first review article summarizing the immunomodulatory effects of BGs for tissue repair and regeneration. The immune response to BGs is firstly introduced, discussing potential mechanisms regarding the immunomodulation effects induced by BGs. Moreover, the interactions between the immune cells involved in the immunomodulation process and BGs (dissolution products) are summarized in detail. Particularly, a well-regulated and timely switch of macrophage phenotype from pro-inflammatory to anti-inflammatory is crucial to constructive tissue regeneration through modulating osteogenesis, osteoclastogenesis, and angiogenesis. The influence of BG characteristics on macrophage responses is discussed. We highlight the strategies employed to harness macrophage responses for enhanced tissue regeneration, including the incorporation of active ions, surface functionalization, and controlled release of immunomodulatory molecules. Finally, we conclude with our perspectives on future research challenges and directions in the emerging field of immunomodulatory BGs for tissue regeneration. Statement of significance: Immunomodulatory effects of bioactive glasses (BGs) in relation to bone regeneration and wound healing have started to be understood. We summarize those studies which have focused on immunomodulatory BGs for tissue regeneration. We first introduce the potential mechanisms of the immunomodulation effects induced by BGs. Interactions between the cells involved in immunomodulation processes and BGs (and their dissolution products, biologically active ions) are elaborated. We highlight the strategies employed to modulate macrophage responses for enhancing tissue regeneration, including incorporation of active ions, surface functionalization, and controlled release of immunomodulatory agents. This is the first review article summarizing and outlining the immunomodulatory effects of BGs for tissue regeneration. We anticipate that increasing research efforts will start to emerge in the area of immunomodulatory BGs.
CRIS-Team Scopus Importer:2021-09-10
Keywords: Bioactive glasses; Bone tissue regeneration; Immune response; Immunomodulation; Macrophages; Wound healing

IMPACT OF 45S5-BIOACTIVE GLASS ON SYNOVIAL CELLS IN KNEE OSTEOARTHRITIS - IN VITRO STUDY - Marinescu, M. R.; Renkawitz, T.; Tripel, E.; Boccaccini, Aldo R.; Moradi, B.; Westhauser, F.; Platzer, H. (OSTEOARTHRITIS AND CARTILAGE, 2022)
CRIS-Team WoS Importer:2022-04-22

Impact of Copper-Doped Mesoporous Bioactive Glass Nanospheres on the Polymerisation Kinetics and Shrinkage Stress of Dental Resin Composites - Marovic, Danijela; Par, Matej; Taubock, Tobias T.; Haugen, Havard J.; Mandic, Visnja Negovetic; Wuethrich, Damian; Burrer, Phoebe; Zheng, Kai; Attin, Thomas; Tarle, Zrinka; Boccaccini, Aldo R. (International Journal of Molecular Sciences, 2022)
We embedded copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) with antibacterial and ion-releasing properties into experimental dental composites and investigated the effect of Cu-MBGN on the polymerisation properties. We prepared seven composites with a BisGMA/TEGDMA (60/40) matrix and 65 wt.% total filler content, added Cu-MBGN or a combination of Cu-MBGN and silanised silica to the silanised barium glass base, and examined nine parameters: light transmittance, degree of conversion (DC), maximum polymerisation rate (R-max), time to reach R-max, linear shrinkage, shrinkage stress (PSS), maximum PSS rate, time to reach maximum PSS rate, and depth of cure. Cu-MBGN without silica accelerated polymerisation, reduced light transmission, and had the highest DC (58.8 +/- 0.9%) and R-max (9.8 +/- 0.2%/s), but lower shrinkage (3 +/- 0.05%) and similar PSS (0.89 +/- 0.07 MPa) versus the inert reference (0.83 +/- 0.13 MPa). Combined Cu-MBGN and silica slowed the R-max and achieved a similar DC but resulted in higher shrinkage. However, using a combined 5 wt.% Cu-MBGN and silica, the PSS resembled that of the inert reference. The synergistic action of 5 wt.% Cu-MBGN and silanised silica in combination with silanised barium glass resulted in a material with the highest likelihood for dental applications in future.
CRIS-Team WoS Importer:2022-08-26

Impact of electrospun scaffold topology on the performance of in-vitro Folliculogenesis applied to preantral ovine follicles - Di Berardino, C.; Liverani, Liliana; Capacchietti, G.; Peserico, A.; Boccaccini, Aldo R.; Barboni, B. (HUMAN REPRODUCTION, 2022)
CRIS-Team WoS Importer:2022-10-21

Impact of morphological features and chemical composition of tendon biomimetic scaffolds on immune recognition via Toll-like receptors - Gil-Cantero, Sara; Iorio, Francesco; Ünalan, Irem; Kurtuldu, Fatih; Künig, Sarojinidevi; Wenhardt, Claus; Pinnaro′, Veronica; Aigner-Radakovics, Katharina; Steinberger, Peter; Boccaccini, Aldo R.; Stöckl, Johannes (Biomaterials Science, 2024)
Tendinopathies are a major worldwide clinical problem. The development of tendon biomimetic scaffolds is considered a promising, therapeutic approach. However, to be clinically effective, scaffolds should avoid immunological recognition. It has been well described that scaffolds composed of aligned fibers lead to a better tenocyte differentiation, vitality, proliferation and motility. However, little has been studied regarding the impact of fiber spatial distribution on the recognition by immune cells. Additionally, it has been suggested that higher hydrophilicity would reduce their immune recognition. Herein, polycaprolactone (PCL)-hyaluronic acid (HA)-based electrospun scaffolds were generated with different fiber diameters (in the nano- and micro-scales) and orientations as well as different grades of wettability and the impact of these properties on immunological recognition has been assessed, by means of Toll-like receptor (TLR) reporter cells. Our results showed that TLR 2/1 and TLR 2/6 were not triggered by the scaffolds. In addition, the TLR 4 signalling pathway seems to be triggered to a greater extent by higher PCL and HA concentrations, but the alignment of the fibers prevents the triggering of this receptor. Taken together, TLR reporter cells were shown to be a useful and effective tool to study the potential of scaffolds to induce immune responses and the results obtained can be used to inform the design of fibrous scaffolds for tendon repair.
CRIS-Team Scopus Importer:2024-08-23

Impact of zinc-or copper-doped mesoporous bioactive glass nanoparticles on the osteogenic differentiation and matrix formation of mesenchymal stromal cells - Westhauser, Fabian; Decker, Simon; Nawaz, Qaisar; Rehder, Felix; Wilkesmann, Sebastian; Moghaddam, Arash; Kunisch, Elke; Boccaccini, Aldo R. (Materials, 2021)
Mesoporous bioactive glass nanoparticles (MBGNs) have gained relevance in bone tissue engineering, especially since they can be used as vectors for therapeutically active ions like zinc (Zn) or copper (Cu). In this study, the osteogenic properties of the ionic dissolution products (IDPs) of undoped MBGNs (composition in mol%: 70 SiO2, 30 CaO) and MBGNs doped with 5 mol% of either Zn (5Zn-MBGNs) or Cu (5Cu-MBGNs; compositions in mol%: 70 SiO2, 25 CaO, 5 ZnO/CuO) on human bone marrow-derived mesenchymal stromal cells were evaluated. Extracellular matrix (ECM) formation and calcification were assessed, as well as the IDPs’ influence on viability, cellular osteogenic differentiation and the expression of genes encoding for relevant members of the ECM. The IDPs of undoped MBGNs and 5Zn-MBGNs had a comparable influence on cell viability, while it was enhanced by IDPs of 5Cu-MBGNs compared to the other MBGNs. IDPs of 5Cu-MBGNs had slightly positive effects on ECM formation and calcification. 5Zn-MBGNs provided the most favorable pro-osteogenic properties since they increased not only cellular osteogenic differentiation and ECM-related gene expression but also ECM formation and calcification significantly. Future studies should analyze other relevant properties of MBGNs, such as their impact on angiogenesis.
CRIS-Team Scopus Importer:2021-04-23
Keywords: Copper; Extracellular matrix; Mesoporous bioactive glass nanoparticles; Osteogenic differentiation; Zinc

Improved 3D Printing and Cell Biology Characterization of Inorganic-Filler Containing Alginate-Based Composites for Bone Regeneration: Particle Shape and Effective Surface Area Are the Dominant Factors for Printing Performance - Bednarzig, Vera; Schrüfer, Stefan; Schneider, Tom; Schubert, Dirk W.; Detsch, Rainer; Boccaccini, Aldo R. (International Journal of Molecular Sciences, 2022)
The use of organic–inorganic 3D printed composites with enhanced properties in biomedical applications continues to increase. The present study focuses on the development of 3D printed alginate-based composites incorporating inorganic fillers with different shapes (angular and round), for bone regeneration. Reactive fillers (bioactive glass 13–93 and hydroxyapatite) and non-reactive fillers (inert soda–lime glass) were investigated. Rheological studies and the characterization of various extrusion-based parameters, including material throughput, printability, shape fidelity and filament fusion, were carried out to identify the parameters dominating the printing process. It was shown that the effective surface area of the filler particle has the highest impact on the printing behavior, while the filler reactivity presents a side aspect. Composites with angular particle morpholo-gies showed the same high resolution during the printing process, almost independent from their reactivity, while composites with comparable amounts of round filler particles lacked stackability after printing. Further, it could be shown that a higher effective surface area of the particles can circumvent the need for a higher filler content for obtaining convincing printing results. In addition, it was proven that, by changing the particle shape, the critical filler content for the obtained adequate printability can be altered. Preliminary in vitro biocompatibility investigations were carried out with the bioactive glass containing ink. The 3D printed ink, forming an interconnected porous scaffold, was analyzed regarding its biocompatibility in direct or indirect contact with the pre-osteoblast cell line MC3T3-E1. Both kinds of cell tests showed increased viability and a high rate of proliferation, with complete coverage of the 3D scaffolds’ surface already after 7 d post cell-seeding.
CRIS-Team Scopus Importer:2022-05-06
Keywords: 3D printing; alginate; bioactive glasses; organic–inorganic composites; rheology

Improvement of the Layer Adhesion of Composite Cardiac Patches - Ruther, Florian; Zimmermann, Andrea; Engel, Felix; Boccaccini, Aldo R. (Advanced Engineering Materials, 2019)
The major purpose of cardiac patches is to deliver healthy cells to infarcted tissues. Such cardiac patches must fulfill specific mechanical as well as chemical requirements. Herein, bi-component cardiac patches are investigated with regard to their layer adhesion. Combinations of salt-leached porous poly (glycerol sebacate) (PGS) films with a layer of electrospun-gelatin fibers are produced. Gelatin fibers are fabricated by solution electrospinning using 20 wt% gelatin in 98 v% formic acid. Fibers are attached to PGS films either via direct electrospinning on top of the film or via combining as spun fiber mats with PGS using gelatin as glue. Scanning electron microscopy (SEM) images show that fiber mats adapt to the rough surface of the porous PGS film. In contrast, fibers spun directly onto films show poor adhesion and only a few fibers are attached to the PGS substrate. Fourier transform infrared (FTIR) analysis, contact-angle measurements, and pull-off adhesion tests of the bi-component patches confirm these results. Modified pull-off adhesion tests of the two layers show that combining as spun gelatin fiber mats with porous PGS substrates by gluing leads to excellent material adhesion before and after incubation for up to 14 days.
CRIS-Team Scopus Importer:2019-11-19
Keywords: bi-layer adhesions; cardiac patches; electrospinning; gelatin; porous poly (glycerol sebacate)

Improvement of the microstructure and mechanical properties of bioceramic scaffolds using electrohydrodynamic spraying with template modification - Muthutantri, Anushini I.; Edirisinghe, Mohan J.; Boccaccini, Aldo R. (Journal of the Mechanical Behavior of Biomedical Materials, 2010)
Porous scaffolds play a key role in tissue engineering (TE) approaches and new processing methods and materials are constantly being developed to cater for the wide range of specifications and requirements. Electrospraying is a relatively new processing method used for producing open-pore scaffolds. In this work, the electrospraying technique was manipulated to make the process more efficient, and the effect of spraying time on the pore size and strut thickness of zirconia scaffolds was explored. Scaffolds of adequate pore size and interconnectivity, with an average compressive strength of ∼7.5 MPa, by electrospraying for only 10 min are reported. The effect of modifying the sacrificial template on the microstructure and mechanical properties of the sintered scaffolds was also investigated. A combination of template surface hydroxylation and improved conductivity produced a thicker ceramic coating, leading to enhanced mechanical properties. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.improv

Improving alginate printability for biofabrication: establishment of a universal and homogeneous pre-crosslinking technique - Hazur, Jonas; Detsch, Rainer; Karakaya, Emine; Kaschta, Joachim; Teßmar, Jörg; Schneidereit, Dominik; Friedrich, Oliver; Schubert, Dirk W.; Boccaccini, Aldo R. (Biofabrication, 2020)
Many different biofabrication approaches as well as a variety of bioinks have been developed by researchers working in the field of tissue engineering. A main challenge for bioinks often remains the difficulty to achieve shape fidelity after printing. In order to overcome this issue, a homogeneous pre-crosslinking technique, which is universally applicable to all alginate-based materials, was developed. In this study, the Young's Modulus after post-crosslinking of selected hydrogels, as well as the chemical characterization of alginate in terms of M/G ratio and molecular weight, were determined. With our technique it was possible to markedly enhance the printability of a 2% (w/v) alginate solution, without using a higher polymer content, fillers or support structures. 3D porous scaffolds with a height of around 5 mm were printed. Furthermore, the rheological behavior of different pre-crosslinking degrees was studied. Shear forces on cells as well as the flow profile of the bioink inside the printing nozzle during the process were estimated. A high cell viability of printed NIH/3T3 cells embedded in the novel bioink of more than 85% over a time period of two weeks could be observed.
CRIS-Team Scopus Importer:2020-07-24
Keywords: alginate; bioink; bioprinting; pre-crosslinking; printability; rheology; shape fidelity

Improving Four-Electrode Impedance Measurements by Numerical Simulations - Arbeiter, Nils; Pobner, Lucas; Schöbel, Lisa; Boccaccini, Aldo R.; Van Rienen, Ursula; Zimmermann, Julius (Proceedings of International Workshop on Impedance Spectroscopy, IWIS 2024, 2024)
The tissue dielectric properties are highly relevant for biomedical engineering applications. Four-electrode impedance measurements offer the possibility of measuring the actual tissue dielectric properties. Accurate measurement of these properties is essential for the development and optimisation of medical devices and treatments. Compared to other measurement approaches, four-electrode measurements are believed to be independent of electrochemical interface effects. We present numerical simulations using the finite element method of a commercial chip that can be used for four-electrode impedance measurements. With that, we establish means to validate experimental setups, characterise the setups regarding measurement ranges, facilitate the choice of measurement equipment and support the optimal placement of measurement electrodes, offering guidance for optimising experimental setups. With different simulation approaches regarding distributed or interface impedances, it is possible to gain insight into the underlying physical concepts. The validated chip allows accurate predictions for further experiments, including more than one material and dispersion.
CRIS-Team Scopus Importer:2025-04-01
Keywords: FEM simulations; four-electrode measurements; impedance spectroscopy; validation

Incorporating silica nanoparticles with silver patches into alginate-based bioinks for 3D bioprinting - Anspach, Annalise; Bider, Faina; Völkl, Andreas; Klupp Taylor, Robin; Boccaccini, Aldo R. (MRS Communications, 2024)
Alginate dialdehyde-gelatin (ADA-GEL) hydrogels are being studied in bioprinting for their combination of cell adhesion and printability. To incorporate specific functionalities and to improve printability, different additives to ADA-GEL inks are being proposed. Here, a novel type of functional nanoparticles comprising silver patches on silica cores was incorporated into ADA-GEL bioinks. Silver patchy particles (SPPs) were present both on the surface and interior of printed structures. Incorporation of SPPs improved printability of ADA-GEL inks and supported osteosarcoma (MG-63) cells over 7 days of culture. SPPs represent a valuable additive for ADA-GEL hydrogels, being attractive to develop bioinks with advanced functionalitie

Incorporation of bioactive glasses containing Mg, Sr, and Zn in electrospun PCL fibers by using benign solvents - Sergi, Rachele; Cannillo, Valeria; Boccaccini, Aldo R.; Liverani, Liliana (Applied Sciences, 2020)
Poly(ε-caprolactone) (PCL) and PCL/bioactive glass composite fiber mats were produced by electrospinning technique. To improve cell adhesion and proliferation (i) 45S5, (ii) a bioactive glass containing strontium and magnesium oxides, and (iii) a bioactive glass containing zinc oxide were separately added to the starting PCL solution before electrospinning. A good incorporation of bioactive glass particles in PCL electrospun mats was confirmed by SEM and FTIR analyses. Bioactivity was evaluated by immersion of PCL mats and PCL/bioactive glass electrospun fiber mats in simulated body fluid (SBF). Bone murine stromal cells (ST-2) were employed in WST-8 assay to assess cell viability, cell morphology, and proliferation. The results showed that the presence of bioactive glass particles in the fibers enhances cell adhesion and proliferation compared to neat PCL mats. Furthermore, PCL/bioactive glass electrospun mats showed higher wound-healing rate (measured as cell migration rate) in vitro compared to neat PCL electrospun mats. Therefore, the characteristics of the PCL matrix combined with biological properties of bioactive glasses make PCL/bioactive glass composite ideal candidate for biomedical application.
CRIS-Team Scopus Importer:2020-09-04
Keywords: Bioactive glass; Composite; Electrospinning; PCL; Wound healing

Incorporation of bioactive glass nanoparticles in electrospun PCL/chitosan fibers by using benign solvents - Liverani, Liliana; Lacina, Jonas; Roether, Judith; Boccardi, Elena; Killian, Manuela; Schmuki, Patrik; Schubert, Dirk W.; Boccaccini, Aldo R. (Bioactive Materials, 2018)

Incorporation of Boron in Mesoporous Bioactive Glass Nanoparticles Reduces Inflammatory Response and Delays Osteogenic Differentiation - Zheng, Kai; Fan, Yuqian; Torre, Elisa; Balasubramanian, Preethi; Taccardi, Nicola; Cassinelli, Clara; Morra, Marco; Iviglia, Giorgio; Boccaccini, Aldo R. (Particle & Particle Systems Characterization, 2020)
Mesoporous bioactive glass nanoparticles (MBG) are multifunctional building blocks for tissue regeneration and nanomedicine applications. Incorporation of biologically active ions can endow MBG with additional functionalities toward promoted therapeutic effects. Here, boron is incorporated into MBG by using a sol–gel approach. The concentration of boron incorporated is controllable by tuning the amount of boron precursor. Two types of boron-doped MBG, namely 10B- and 15B-MBG (5.8 and 6.5 mol% of B2O3, respectively) are synthesized. Boron incorporation does not significantly influence the particle morphology. All synthesized particles exhibit a sphere-like shape with a size ranging from 100 to 300 nm. 10B- and 15B-MBG show large specific surface area (346 and 320 m² g−1, respectively) and pore volume. Both boron-doped MBG exhibit remarkable in vitro bioactivity and noncytotoxicity. Boron incorporation is shown to reduce the inflammatory response linked to macrophages as indicated by downregulated expression of pro-inflammatory genes. However, boron incorporation delays the osteogenic differentiation in osteoblasts as indicated by the downregulated expression of pro-osteogenic genes. The results demonstrate the promising potential of using boron-doped MBG to modulate inflammatory response for bone regeneration under inflammatory conditions, as shown in this study for the first time.
CRIS-Team Scopus Importer:2020-06-09
Keywords: bioactive glasses; bioactivity; boron; inflammatory response; osteogenic activity

Incorporation of calcium containing mesoporous (MCM-41-type) particles in electrospun PCL fibers by using benign solvents - Liverani, Liliana; Boccardi, Elena; Maria Beltran, Ana; Boccaccini, Aldo R. (Polymers, 2017)
Keywords: Benign solvents; Composites; Electrospinning; Mesoporous silica calcium containing MCM-41; Nanofibers; Poly(epsilon-caprolactone)

Incorporation of copper-doped mesoporous bioactive glass nanospheres in experimental dental composites: Chemical and mechanical characterization - Marovic, Danijela; Haugen, Håvard J.; Negovetic Mandic, Visnja; Par, Matej; Zheng, Kai; Tarle, Zrinka; Boccaccini, Aldo R. (Materials, 2021)
Experimental dental resin composites incorporating copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) were designed to impart antibacterial and remineralizing properties. The study evaluated the influence of Cu-MBGN on the mechanical properties and photopolymer-ization of resin composites. Cu-MBGN were synthesized using a microemulsion-assisted sol–gel method. Increasing amounts of Cu-MBGN (0, 1, 5, and 10 wt %) were added to the organic polymer matrix with inert glass micro-and nanofillers while maintaining a constant resin/filler ratio. Six tests were performed: X-ray diffraction, scanning electron microscopy, flexural strength (FS), flexural modulus (FM), Vickers microhardness (MH), and degree of conversion (DC). FS and MH of Cu-MBGN composites with silica fillers showed no deterioration with aging, with statistically similar results at 1 and 28 days. FM was not influenced by the addition of Cu-MBGN but was reduced for all tested materials after 28 days. The specimens with 1 and 5% Cu-MBGN had the highest FS, FM, MH, and DC values at 28 days, while controls with 45S5 bioactive glass had the lowest FM, FS, and MH. DC was high for all materials (83.7–93.0%). Cu-MBGN composites with silica have a potential for clinical implementation due to high DC and good mechanical properties with adequate resistance to aging.
CRIS-Team Scopus Importer:2021-06-11
Keywords: Bioactive glass; Copper; Dental; Mesoporous; Nanoparticles; Resin composites

Incorporation of Cu-Containing Bioactive Glass Nanoparticles in Gelatin-Coated Scaffolds Enhances Bioactivity and Osteogenic Activity - Zheng, Kai; Wu, Jingjing; Li, Wei; Dippold, Dirk; Wan, Ying; Boccaccini, Aldo R. (ACS Biomaterials Science and Engineering, 2018)
Keywords: bioactive nanoparticles; bone regeneration; silicate bioactive glasses; copper; porous scaffolds

Incorporation of vitamin E in poly(3hydroxybutyrate)/Bioglass composite films: effect on surface properties and cell attachment - Misra, Superb K.; Philip, Sheryl E.; Chrzanowski, Wojciech; Nazhat, Showan N.; Roy, Ipsita; Knowles, Jonathan C.; Salih, Vehid; Boccaccini, Aldo R. (Journal of the Royal Society Interface, 2009)
This study investigated the possibility of incorporating α-tocopherol (vitamin E) into poly(3hydroxybutyrate) (P(3HB))/Bioglass composites, which are being developed for bone tissue engineering matrices. P(3HB) films with 20 wt% Bioglass and 10 wt% vitamin E were prepared using the solvent casting technique. Addition of vitamin E significantly improved the hydrophilicity of the composites along with increasing the total protein adsorption. The presence of protein adsorbed on the composite surface was further confirmed using X-ray photoelectron spectroscopy analysis. Preliminary cell culture studies using MG-63 human osteoblasts showed that the addition of vitamin E in the P(3HB)/20 wt% Bioglass films significantly increased cell proliferation. The results achieved in this study confirmed the possibility of incorporating vitamin E as a suitable additive in P(3HB)/Bioglass composites to engineer the surface of the composites by promoting higher protein adsorption and increasing the hydrophilicity. © 2008 The Royal Society.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.incorp
Keywords: α-tocopherol; Bioglass; Composites; tissue engineering; MG-63 osteoblasts; Poly(3hydroxybutyrate)

Incorporation of zinc into binary SiO2-CaO mesoporous bioactive glass nanoparticles enhances anti-inflammatory and osteogenic activities - Sun, Haishui; Zheng, Kai; Zhou, Tian; Boccaccini, Aldo R. (Pharmaceutics, 2021)
During the healing and repair of bone defects, uncontrolled inflammatory responses can compromise bone regeneration. Biomaterials with anti-inflammatory activity are favorable for bone tissue regeneration processes. In this work, multifunctional Zn-containing mesoporous bioactive glass nanoparticles (Zn-MBGs) exhibiting favorable osteogenic and anti-inflammatory activities were produced employing a sol-gel method. Zn-MBGs exhibited a mesoporous spherical shape and nanoscale particle size (100 ± 20 nm). They were degradable in cell culture medium, and could release Si, Ca, and Zn in a sustained manner. Zn-MBGs also exhibited a concentration-dependent cellular response. The extract of Zn-MBGs obtained by incubation at 0.1 mg/mL (in culture medium) for 24 h could enhance in vitro mineralization, alkaline phosphatase activity, the expression of osteogenesis-related genes, and the production of intracellular protein osteocalcin of rat bone marrow stromal cells (BMSCs). Moreover, the extract of Zn-MBGs at 0.1 mg/mL could significantly downregulate the expression of inflammatory genes and the production of inducible nitric oxide in RAW 264.7 cells, particularly under stimulation of inflammatory signals interferon-γ (IFN-γ) and lipopolysaccharide (LPS). Zn-MBGs also inhibited the pro-inflammatory M1 polarization of RAW264.7 cells induced by LPS and IFN-γ. In summary, we successfully synthesized Zn-MBGs with concentration-dependent osteogenic and anti-inflammatory activities. Zn-MBGs show their great potential in immunomodulation strategies for bone regeneration, representing a multifunctional biomaterial that can be applied to regenerate bone defects under inflammatory conditions.
CRIS-Team Scopus Importer:2021-12-31
Keywords: Anti-inflammatory; Bioactive glasses; Immunomodulation; Osteogenic differentiation; Zinc

Increase in VEGF secretion from human fibroblast cells by bioactive glass S53P4 to stimulate angiogenesis in bone - Detsch, Rainer; Stoor, Patricia; Gruenewald, Alina; Roether, Judith; Lindfors, Nina C.; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2014)
Bioactive glasses (BAGs) are being investigated for the repair and reconstruction of bone defects, as they exhibit osteoconductive and osteostimulatory potential. However, successful bone regeneration requires also the neovascularization of the construct which is, among other factors, guided by vascular endothelial growth factor (VEGF). In this study, BAG S53P4 (53% SiO, 23% NaO, 20% CaO, 4% PO) is investigated in relation to VEGF-release and response of fibroblast cells. Human CD-18CO fibroblasts were cultivated in contact with different granules of different sizes (0.5-0.8 mm, 1.0-2.0 mm, and 2.0-3.15 mm) and at different concentrations (0-1 wt/vol % of BAG) for 72 h. The analysis of morphology revealed no toxic effect for all granule sizes and concentrations. Compared with the reference, lactate dehydrogenase-activity of CCD-18CO cells increased in contact with BAG samples. The VEGF release from CCD-18CO fibroblasts cultured on different granule sizes and at different concentrations after 72 h of incubation was quantified. It was found that particles of 0.5-0.8 mm and 1.0-2.0 mm in size enhanced VEGF release, whereas BAG particle sizes of 2.0- 3.15 mm led to inhibition of VEGF release. The results are relevant to understand the influence of the particle size and concentration of BAG S53P4 on VEGF expression and neovascularization.
Keywords: Bioactive glass; Bone tissue engineering; Fibroblast; Vascularization; VEGF

Indirect rapid prototyping of biphasic calcium phosphate scaffolds as bone substitutes: Influence of phase composition, macroporosity and pore geometry on mechanical properties - Detsch, Rainer; et al. (Journal of Materials Science: Materials in Medicine, 2010)
While various materials have been developed for bone substitute and bone tissue engineering applications over the last decades, processing techniques meeting the high demands of scaffold shaping are still under development. Individually adapted and mechanically optimised scaffolds can be derived from calcium phosphate (CaP-) ceramics via rapid prototyping (RP). In this study, porous ceramic scaffolds with a periodic pattern of interconnecting pores were prepared from hydroxyapatite, β- tricalcium phosphate and biphasic calcium phosphates using a negative-mould RP technique. Moulds predetermining various pore patterns (round and square cross section, perpendicular and 60° inclined orientation) were manufactured via a wax printer and subsequently impregnated with CaP-ceramic slurries. Different pore patterns resulted in macroporosity values ranging from about 26.0-71.9 vol% with pore diameters of approximately 340 μm. Compressive strength of the specimens (1.3-27.6 MPa) was found to be mainly influenced by the phase composition as well as the macroporosity, both exceeding the influence of the pore geometry. A maximum was found for scaffolds with 60 wt% hydroxyapatite and 26.0 vol% open porosity. It has been shown that wax ink-jet printing allows to process CaP-ceramic into scaffolds with highly defined geometry, exhibiting strength values that can be adjusted by phase composition and pore geometry. This strength level is within and above the range of human cancellous bone. Therefore, this technique is well suited to manufacture scaffolds for bone tissue engineering. © Springer Science+Business Media, LLC 2010.

Induction of VEGF secretion from bone marrow stromal cell line (ST-2) by the dissolution products of mesoporous silica glass particles containing CuO and SrO - Balasubramanian, Preethi; Salinas, Antonio J.; Sanchez-Salcedo, Sandra; Detsch, Rainer; Vallet-Regi, Maria; Boccaccini, Aldo R. (Journal of Non-Crystalline Solids, 2018)
Keywords: Angiogenesis; Bioactive glasses; Mesoporosity; Bone marrow stromal cells; Ion release

Influence of Aggregated Powder Structures on Sintering Behaviour of Multilayer Hydroxyapatite Laminates - Hahn, E.; Hum, Jasmin; Will, Julia; Zuo, K.; Jiang, D.; Greil, Peter (Journal of Ceramic Science and Technology, 2011)
Aqueous tape-cast slurries of hydroxyapatite with a solid loading of 32 vol% were prepared from various fractions of aggregated (mean particle size 4.7-5.6 mu m) and dispersed powder (mean particle size 0.17-0.29 mu m). Multilayer laminates were prepared and the shrinkage and density of the laminates sintered at 1250 degrees C were measured. While fractional density in the green laminates remains almost constant at 0.52, a pronounced increase in fractional sintered density from 0.96 to >0.99 was observed with decreasing fraction of aggregated powder. Residual pore size and pore number density were reduced from 0.58 mu m to 0.48 mu m and 0.049 pores/mu m(2) to 0.019 pores/mu m(2), respectively. The multilayer laminates attained a mean bending strength of 118 +/- 10 MPa measured with the bi-axial bending test. An osteosynthesis plate design was fabricated for demonstration of the potential of sintered multilayer laminates.
Keywords: Hydroxyapatite; laminate sintering; aggregated and dispersed powder

Influence of Copper-Strontium Co-Doping on Bioactivity, Cytotoxicity and Antibacterial Activity of Mesoporous Bioactive Glass - Anand, Akrity; Sengupta, Susanta; Kankova, Hana; Svancarkova, Anna; Beltran, Ana M.; Galusek, Dusan; Boccaccini, Aldo R.; Galuskova, Dagmar (Gels, 2022)
Mesoporous bioactive glass (MBG) is an extensively studied biomaterial used for the healing of bone defects. Its biological applications can be tailored by introducing metallic ions, such as strontium (Sr) and copper (Cu), which can enhance its functionalities, including osteogenetic, angiogenetic and antibacterial functionalities. In this study, Cu and Sr ions were co-doped (ratio 1:1) with x = 0.5, 1 and 2 mol% each in glass with an intended nominal composition of 80SiO(2)-(15-2x)CaO-5P(2)O(5)-xCuO-xSrO and synthesized with an evaporation-induced self-assembly (EISA)-based sol-gel technique. XRD confirmed the amorphous nature of the glass, while compositional analysis using ICP-OES confirmed the presence of dopant ions with the required amounts. A TEM study of the MBG powders showed fringes that corresponded to the formation of a highly ordered mesoporous structure. The Cu-Sr-doped MBG showed a positive effect on apatite formation when immersed in SBF, although the release of Cu and Sr ions was relatively slow for 1 mol% of each co-dopant, which signified a stable network structure in the glass. The impact of the Cu and Sr ions on the osteoblast-like cell line MG-63 was assessed. At the particle concentrations of 1 wt./vol.% or lower, the cell viability was above 50%. An antibacterial test was conducted against Gram-negative E. coli and Gram-positive S. aureus bacteria. With a sequential increase in the co-doped ion content in the glass, the zone of inhibition for bacteria increased. The results suggest that the doping of MBG with Cu and Sr ions at up to 2 mol% can result in tailored sustained release of ions to enhance the applicability of the studied glass as a functional biomaterial for bone regeneration applications.
CRIS-Team WoS Importer:2023-01-06

Influence of dissolution products of a novel Ca-enriched silicate bioactive glass-ceramic on VEGF release from bone marrow stromal cells - Balasubramanian, Preethi; Detsch, Rainer; Esteban-Tejeda, Leticia; Grünewald, Alina; Moya, Jose S.; Boccaccini, Aldo R. (Biomedical Glasses, 2017)

Influence of functionalized halloysite clays (HNT) on selected properties of multiblock (e)PBS-EG copolymer obtained by enzymatic catalysis - Gradzik, Boguslawa; Stenzel, Alexander; Boccaccini, Aldo R.; El Fray, Miroslawa (Designed Monomers and Polymers, 2015)
In this paper, we discuss the functionalization of halloysite aluminosilicate clays (HNT) with anionic surfactant - sodium dodecanoate (NaL) and their use in new polymeric nanocomposites preparation via solvent casting. The selected polymer matrix were segmented; copoly(ester-ether)s - poly(butylene succinate-co-ethylene glycol) (PBS-EG) were synthesized for the first time with the use of enzymatic catalyst from Candida antarctica lipase B. The influence of variable concentration of NaL, temperature, and time on functionalization and finally on the chemical structure (IR) and colloidal stability (zeta potential) of functionalized HNT (f-HNT) was examined. Nanocomposites were prepared via solvent casting process, where 1 wt% of HNTs and 1 wt% of f-HNT clays were added to the (e)PBS-EG solution in chloroform. The chemical structure, topography, and hydrophilic/hydrophobic properties of prepared nanocomposites were determined by nuclear magnetic resonance (1H NMR), infrared spectroscopy (IR), scanning electron microscopy, and water contact angle. It was observed that higher concentration of NaL, longer modification time, and higher temperature lead to even distribution of f-HNT into (e)PBS-EG matrix. Halloysite clays in general improved the hydrophilicity of (e)PBS-EG and f-HNT was found to act as nucleating agent during polymer crystallization.
Keywords: aluminosilicates; enzymatic synthesis; halloysite clays; nanocomposites; poly(butylene succinate) (PBS)

Influence of In-Situ Electrochemical Oxidation on Implant Surface and Colonizing Microorganisms Evaluated by Scanning Electron Microscopy - Göltz, Maximilian; Koch, Maximilian; Detsch, Rainer; Karl, Matthias; Burkovski, Andreas; Rosiwal, Stefan (Materials, 2019)
Peri-implantitis is a worldwide increasing health problem, caused by infection of tissue and bone around an implant by biofilm-forming microorganisms. Effects of peri-implantitis treatment using mechanical debridement, air particle abrasion and electrochemical disinfection on implant surface integrity were compared. Dental implants covered with bacterial biofilm were cleaned using mechanical debridement and air particle abrasion. In addition, implants were disinfected using a novel electrochemical technique based on an array of boron-doped diamond (BDD) coated electrodes. Following treatment and preparation, the implants were inspected by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical debridement led to changes in surface topography destroying the manufacturer’s medium-rough surface by scratch formation. Air particle abrasion led to accumulation of the abrasive used on the implant surface. With both treatment options, appearance of bacteria and yeasts was not affected. In contrast, electrochemical disinfection did not cause alterations of the implant surface but resulted in distorted microbial cells. Electrochemical disinfection of implant surfaces using BDD electrodes may constitute a promising treatment option for cleaning dental implant surfaces without negatively affecting materials and surface properties.
Keywords: Candida; Enterococcus; debridement; peri-implantitis; disinfection; microscopy; electron; scanning

Influence of Mesoporous Bioactive Glass Particles Doped with Cu and Mg on the Microstructure and Properties of Zein-Based Coatings Obtained by Electrophoretic Deposition - Maciąg, F.; Moskalewicz, T.; Cholewa-Kowalska, K.; Hadzhieva, Zoya; Dziadek, M.; Dubiel, B.; Łukaszczyk, A.; Boccaccini, Aldo R. (Journal of The Electrochemical Society, 2023)
Cu- and Mg-doped mesoporous sol-gel bioactive glasses (MSGG) were developed and their microstructure was investigated. Selected biological tests were also performed to assess their suitability for the functionalization of polymer zein coatings. The electrophoretic deposition (EPD) conditions to obtain composite coatings on Ti-13Nb-13Zr substrates were determined. The coatings with excellent adhesion to the substrates were macroscopically uniform, exhibiting open porosity and high roughness. The surfaces of the samples coated with MSGG/zein coatings became more hydrophilic than the titanium alloy substrates. However, with increase of the volume fraction of glass particles in the coatings, the contact angle increased. The coated alloy showed enhanced resistance to electrochemical corrosion in Ringer’s solution. The chemical composition of the glass used in the coating affected the parameters of wettability and resistance to electrochemical corrosion. Both coating types showed an increase in the antibacterial properties against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria compared to pure zein. However, no significant differences were observed after a 24 h-long test.
CRIS-Team Scopus Importer:2023-08-25
Keywords: coating; electrophoretic deposition; mesoporous sol-gel bioactive glass; titanium biomaterials; zein

Influence of metakaolin characteristics on the mechanical properties of geopolymers - Kuenzel, C.; Neville, T. P.; Donatello, Shane; Vandeperre, Luc; Boccaccini, Aldo R.; Cheeseman, C. R. (Applied Clay Science, 2013)
The relationship between the properties of geopolymers and the characteristics of metakaolin samples used in their preparation has been investigated. Three commercial metakaolin samples have been characterised using 27Al-NMR to determine the coordination number of Al (IV, V and VI), and by acid and alkali dissolution to determine the reactive Si and Al content. The setting and mechanical properties of geopolymers formed from the metakaolin samples under identical conditions are reported, using Weibull statistics to analyse strength data. Although the metakaolin samples contained different levels of five coordinated aluminium (Al (V)) the mechanical properties of the geopolymers formed were very similar. The reactive fraction of metakaolinite determined by dissolution in 8M NaOH provides the most relevant long-term indicator of geopolymer performance. © 2013 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.influe
Keywords: Geopolymer; Metakaolin; Reactive content; Weibull statistics

Influence of proteins on the corrosion behavior of a chitosan-bioactive glass coated magnesium alloy - Höhlinger, Michael; Christa, Daniel; Zimmermann, Victoria; Heise, Svenja; Boccaccini, Aldo R.; Virtanen, Sannakaisa (Materials Science and Engineering C, 2019)
The current study explored the degradation behavior of a WE43 Mg alloy during immersion tests in Dulbecco's Modified Eagle's Medium (DMEM) for 3d and 7d, for a bare alloy surface as well as for samples with surface pretreatment, and finally for samples coated with chitosan-bioactive glass. The immersion tests were conducted with and without addition of serum, to study the influence of proteins on the degradation process. Mass-loss was measured to determine the corrosion rate after 3d and 7d of immersion. The samples were analyzed by SEM with respect to their surface morphology and the chemical composition was screened by high-resolution XPS. The results demonstrate not only a significant, time-dependent influence of serum addition on the corrosion behavior of the materials studied, but noteworthy is that depending on the sample type, proteins in solution were observed to either accelerate or inhibit corrosion. These results are discussed in correlation to observed changes in surface chemistry taking place upon immersion in the absence and presence of proteins.
CRIS-Team WoS Importer:2019-06-04

Influence of random and designed porosities on 3D printed tricalcium phosphate-bioactive glass scaffolds - Bose, Susmita; Bhattacharjee, Arjak; Banerjee, Dishary; Boccaccini, Aldo R.; Bandyopadhyay, Amit (Additive Manufacturing, 2021)
Calcium phosphate (CaP)-based ceramics are a popular choice for bone-graft applications due to their compositional similarities with bone. Similarly, Bioactive glass (BG) is also common for bone tissue engineering applications due to its excellent biocompatibility and bone binding ability. We report tricalcium phosphate (TCP)-BG (45S5 BG) composite scaffolds using conventional processing and binder jetting-based 3D printing (3DP) technique. We hypothesize that BG's addition in TCP will enhance densification via liquid phase sintering and improve mechanical properties. Further, BG addition to TCP should modulate the dissolution kinetics in vitro. This work's scientific objective is to understand the influence of random vs. designed porosity in TCP-BG ceramics towards variations in compressive strength and in vitro biocompatibility. Our findings indicate that a 5 wt% BG in TCP composite shows a compressive strength of 26.7 ± 2.7 MPa for random porosity structures having a total porosity of 47.9%. The same composition in a designed porosity structure shows a compressive strength of 21.3 ± 2.9 MPa, having a total porosity of 54.1%. Scaffolds are also tested for their dissolution kinetics and in vitro bone cell materials interaction, where TCP-BG compositions show favorable bone cell materials interactions. The addition of BG enhances a flaky hydroxycarbonate apatite (HCA) layer in 8 weeks in vitro. Our research shows that the porous TCP- BG scaffolds, fabricated via binder jetting method with enhanced mechanical properties and dissolution properties can be utilized in bone graft applications.
CRIS-Team Scopus Importer:2021-03-19
Keywords: 3D printing; Bioactive glass; Cytocompatibility; In vitro dissolution; Scaffolds