Novel nanocomposite biomaterials with controlled copper/calcium release capability for bone tissue engineering multifunctional scaffolds - Cattalini, J. P.; Hoppe, Alexander; Pishbin, F.; Roether, Judith; Boccaccini, Aldo R.; Lucangioli, S.; Mourino, V. (Journal of the Royal Society Interface, 2015)
This work aimed to develop novel composite biomaterials for bone tissue engineering (BTE) made of bioactive glass nanoparticles (Nbg) and alginate cross-linked with Cu2+ or Ca2+ (AlgNbgCu, AlgNbgCa, respectively). Twodimensional scaffolds were prepared and the nanocomposite biomaterials were characterized in terms of morphology, mechanical strength, bioactivity, biodegradability, swelling capacity, release profile of the cross-linking cations and angiogenic properties. It was found that both Cu2+ and Ca2+ are released in a controlled and sustained manner with no burst release observed. Finally, in vitro results indicated that the bioactive ions released from both nanocomposite biomaterials were able to stimulate the differentiation of rat bone marrow-derived mesenchymal stem cells towards the osteogenic lineage. In addition, the typical endothelial cell property of forming tubes in Matrigel was observed for human umbilical vein endothelial cells when in contact with the novel biomaterials, particularly AlgNbgCu, which indicates their angiogenic properties. Hence, novel nanocomposite biomaterials made of Nbg and alginate cross-linked with Cu2+ or Ca2+ were developed with potential applications for preparation of multifunctional scaffolds for BTE.
Keywords: Alginate; Angiogenesis; Bioactive glass; Bone tissue engineering; Metal ion release; Nanocomposites

Novel PGS/PCL electrospun fiber mats with patterned topographical features for cardiac patch applications - Tallawi, Marwa; Dippold, Dirk; Rai, Ranjana; D'Atri, D.; Roether, Judith; Schubert, Dirk W.; Rosellini, E.; Engel, Felix; Boccaccini, Aldo R. (Materials Science and Engineering C, 2016)
Nano- and micro-scale topographical features play a critical role in the induction and maintenance of various cellular properties and functions, including morphology, adhesion, gene regulation, and cell-to-cell communication. In addition, recent studies have indicated that the structure and function of heart tissue are also sensitive to mechanical cues at the nano- and micro-scale. Although fabrication methods exist for generating topographical features on polymeric scaffolds for cell culture, current techniques, especially those with nano-scale resolution, are typically complex, prohibitively expensive and not accessible to most biology laboratories. Here, we present a simple and tunable fabrication method for the production of patterned electrospun fibers that simulate the complex anisotropic and multi-scale architecture of cardiac tissue, to promote cardiac cell alignment. This method is based on the combination of electrospinning and soft lithography techniques, in which electrospun fibers, based on a blend of poly(glycerol sebacate) and poly(caprolactone), were collected on a patterned Teflon-coated silicon wafer with imprinted topographical features. Different surface topographies were investigated, such as squares and grooves, with constant or different interspatial distances. In vitro cell culture studies successfully demonstrated the alignment of both C2C12 myoblasts and neonatal rat cardiomyocytes on fabricated electrospun patterned surfaces. C2C12 cells were cultured over a period of 72h to study the effect of topographical cues on cell morphology. Cells attached within the first 8h after seeding and after 24h most of the cells started to align responding to the topographical cues. Similarly, cardiomyocytes responded to the topographical features by aligning themselves and by expressing Connexin 43 along cellular junctions. Summarizing, we have developed a new method with the potential to significantly promote cardiac tissue engineering by fabricating electrospun fibers with defined topographical features to guide and instruct donor and/or host cells.
EVALuna:34665

Novel poly(3-hydroxybutyrate) composite films containing bioactive glass nanoparticles for wound healing applications - Francis, Lydia; Meng, Decheng; Locke, Ian C.; Knowles, Jonathan C.; Mordan, Nicola; Salih, Vehid; Boccaccini, Aldo R.; Roy, Ipsita (Polymer International, 2016)
Keywords: Bioactive glass; Cell response; n-BG; N-BG/P(3HB) composite films; P(3HB) microspheres; Surface roughness; Wound healing

Novel Poly(3-hydroxyoctanoate)/Poly(3-hydroxybutyrate) blends for medical applications - Basnett, P.; Ching, K. Y.; Stolz, M.; Knowles, J. C.; Boccaccini, Aldo R.; Smith, C.; Locke, I. C.; Keshavarz, T.; Roy, I. (Reactive & Functional Polymers, 2013)
Novel Poly(3-hydroxybutyrate)/Poly(3-hydroxyoctanoate) blends were developed with varying amounts of Poly(3-hydroxyoctanoate), P(3HO) and Poly(3-hydroxybutyrate), P(3HB) for their potential use in various medical applications. These blend films exhibited higher tensile strength and Young's modulus values compared to neat P(3HO). The overall protein adsorption and % cell viability was also found to be significantly higher in the blend films than the neat P(3HO) film. Hydrolytic degradation was faster in the blend films and the degradation rate could potentially be tailored to achieve the optimum rate required for a particular medical application. Hence, these novel blends were found to be highly biocompatible with surface, mechanical and thermal properties suitable for a range of potential medical applications, a great step forward in the area of medical materials. © 2013 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.novelp
Keywords: Biodegradability; Cytotoxicity; Poly(3- hydroxyoctanoate); Poly(3-hydroxybutyrate); Polyhydroxyalkanoates

Novel poly(butylene succinate) nanocomposites containing strontium hydroxyapatite nanorods with enhanced osteoconductivity for tissue engineering applications - Nerantzaki, M.; Filippousi, M.; Van Tendeloo, G.; Terzopoulou, Z.; Bikiaris, D.; Goudouri, Ourania Menti; Detsch, Rainer; Grüenewald, A.; Boccaccini, Aldo R. (eXPRESS Polymer Letters, 2015)
Three series of poly(butylene succinate) (PBSu) nanocomposites containing 0.5, 1 and 2.5 wt% strontium hydroxyapatite [Sr5(PO4)3OH] nanorods (SrHAp nrds) were prepared by in situ polymerisation. The structural effects of Sr5(PO4)3OH nanorods, for the different concentrations, inside the polymeric matrix (PBSu), were studied through high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). HAADF-STEM measurements revealed that the SrHAp nanorods at low concentrations are dispersed inside the polymeric PBSu matrix while in 1 wt% some aggregates are formed. These aggregations affect the mechanical properties giving an enhancement for the concentration of 0.5 wt% SrHAp nrds in tensile strength, while a reduction is recorded for higher loadings of the nanofiller. Studies on enzymatic hydrolysis revealed that all nanocomposites present higher hydrolysis rates than neat PBSu, indicating that nanorods accelerate the hydrolysis degradation process. In vitro bioactivity tests prove that SrHAp nrds promote the formation of hydroxyapatite on the PBSu surface. All nanocomposites were tested also in relevant cell culture using osteoblast-like cells (MG-63) to demonstrate their biocompatibility showing SrHAp nanorods support cell attachment.
Keywords: Nanocomposites; Poly(butylene succinate); Scaffolds; Strontium nanorods

Novel poly(hydroxyalkanoates)-based composites containing Bioglass® and calcium sulfate for bone tissue engineering - García-García, Jose; Garrido, Leoncio; Quijada-Garrido, Isabel; Kaschta, Joachim; Schubert, Dirk W.; Boccaccini, Aldo R. (Biomedical Materials, 2012)
Three different poly(hydroxyalkanoates) (PHAs), copolymers of poly(3-hydroxybutyrate) (P3HB), have been used to make composites using two different fillers, bioactive glass (type 45S5 Bioglass®) and calcium sulfate dihydrate. The PHAs used were poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [PHBHV] and two copolymers of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [PHBHHx]. The aim of the study was the fabrication and characterization of the new composites and the assessment of the influence of the particular filler combination on the physical properties and bioactivity of the films. The thermal behaviour was studied using differential scanning calorimetry while mechanical properties were evaluated using dynamic mechanic thermal analysis and tensile strength test. The mechanical and thermal properties were affected by particles addition. The distribution of the particles in the polymer matrix, observed by scanning electron microscopy, was directly related to the mechanical properties. The surface characteristics were investigated by contact angle measurements and Raman spectroscopy. The extent of formation of hydroxyapatite (HA) upon immersion in simulated body fluid (SBF) depended on the polymer used, the amount of fillers employed and the time of immersion in SBF. Bioactivity was enhanced in the composites with a rise of hydrophilicity. The HA formation was controllable with time in the case of PHBHHx composites.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.novelp

Novel poly(hydroxyalkanoates)-based composites containing Bioglass (R) and calcium sulfate for bone tissue engineering - García-García, Jose; Garrido, Leoncio; Quijada-Garrido, Isabel; Kaschta, Joachim; Schubert, Dirk W.; Boccaccini, Aldo R. (Biomedical Materials, 2012)
Three different poly(hydroxyalkanoates) (PHAs), copolymers of poly(3-hydroxybutyrate) (P3HB), have been used to make composites using two different fillers, bioactive glass (type 45S5 Bioglass (R)) and calcium sulfate dihydrate. The PHAs used were poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [PHBHV] and two copolymers of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [PHBHHx]. The aim of the study was the fabrication and characterization of the new composites and the assessment of the influence of the particular filler combination on the physical properties and bioactivity of the films. The thermal behaviour was studied using differential scanning calorimetry while mechanical properties were evaluated using dynamic mechanic thermal analysis and tensile strength test. The mechanical and thermal properties were affected by particles addition. The distribution of the particles in the polymer matrix, observed by scanning electron microscopy, was directly related to the mechanical properties. The surface characteristics were investigated by contact angle measurements and Raman spectroscopy. The extent of formation of hydroxyapatite (HA) upon immersion in simulated body fluid (SBF) depended on the polymer used, the amount of fillers employed and the time of immersion in SBF. Bioactivity was enhanced in the composites with a rise of hydrophilicity. The HA formation was controllable with time in the case of PHBHHx composites.

Novel porous Al2O3-SiO2-TiO2 bone grafting materials: Formation and characterization - Naga, Salma M.; El-Kady, Abeer M.; El-Maghraby, Hesham F.; Awaad, Mohamed; Detsch, Rainer; Boccaccini, Aldo R. (Journal of Biomaterials Applications, 2014)
The present article deals with the development of 3D porous scaffolds for bone grafting. They were prepared based on rapid fluid infiltration of Al2O3-SiO2 sol into a polyethylene non-woven fabric template structure. Titanium dioxide in concentration equal to 5 wt% was added to the Al2O3-SiO2 mixture to produce Al2O3-SiO2-TiO2 composite scaffolds. The prepared scaffolds are characterized by means of X-ray diffraction, scanning electron microscopy and three-point bending test techniques. The bioactivity of the produced bodies is discussed, including the in vitro and in vivo assessments. The produced scaffolds exhibit mean total porosity of 66.0% and three-point bending strength of 7.1 MPa. In vitro studies showed that MG-63 osteoblast-like cells attach and spread on the scaffolds surfaces. Furthermore, cells grew through the scaffolds and start to produce extra-cellular matrix. Additionally, in vivo studies revealed the ability of the porous scaffolds to regenerate bone tissue in femur defects of albino rats 5 months post surgery. Histological analysis showed that the defect is almost entirely filled with new bone. The formed bone is characterized as a mature bone. The produced bone grafts are intended to be used as bone substitute or bone filler as their degradation products caused no inflammatory effects. © 2013 The Author(s).
Keywords: bioceramics; Bone grafting; in vitro; in vivo; porous materials

Novel sintered glass-ceramics from vitrified oil well drill cuttings - Abbe, O. E.; Grimes, S. M.; Fowler, G. D.; Boccaccini, Aldo R. (Journal of Materials Science, 2009)
An amorphous glass was obtained by melting drill cuttings from oil and gas exploration and production operations in the North Sea that have been blended with sodium and calcium oxides to minimise the melting temperature. Mixtures containing dried drill cuttings:sodium oxide:calcium oxide in the weight ratio 8:1:1 held at 1300 °C for 5 h produce an amorphous solid that can be further treated at temperatures between 750 and 800 °C to give a largely crystalline glass-ceramic. The glass-ceramics have been characterised by physical, chemical and mechanical analyses and shown to have properties of machinability, strength, wear-abrasiveness, thermal resistance, resistance to crack propagation, and stability towards leaching that make the materials suitable for tiling applications, allowing diversion of the drill cutting wastes from final disposal in landfill. © 2009 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.novels

Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells - Strobel, Leonie; Hild, N.; Mohn, D.; Stark, W. J.; Hoppe, Alexander; Gbureck, U.; Horch, Raymund E.; Kneser, U.; Boccaccini, Aldo R. (Journal of Nanoparticle Research, 2013)
The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30-35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 μg/cm (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 μg/cm, Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes. © 2013 Springer Science+Business Media Dordrecht.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.novels
Keywords: Bioactive glass; Bone tissue engineering; Human bone marrow stromal cells; Nanoparticles; Osteogenic differentiation; Strontium

Numerical simulation of electrospinning process in commercial and in-house software PAK - Sustersic, Tijana; Liverani, Liliana; Boccaccini, Aldo R.; Savic, Slobodan; Janicijevic, Aco; Filipovic, Nenad (Materials Express, 2019)
Keywords: electrospinning; two-phase flow; electrospun fibers; numerical simulation

Numerical simulations as means for tailoring electrically conductive hydrogels towards cartilage tissue engineering by electrical stimulation - Zimmermann, Julius; Distler, Thomas; Boccaccini, Aldo R.; van Rienen, Ursula (Molecules, 2020)
Cartilage regeneration is a clinical challenge. In recent years, hydrogels have emerged as implantable scaffolds in cartilage tissue engineering. Similarly, electrical stimulation has been employed to improve matrix synthesis of cartilage cells, and thus to foster engineering and regeneration of cartilage tissue. The combination of hydrogels and electrical stimulation may pave the way for new clinical treatment of cartilage lesions. To find the optimal electric properties of hydrogels, theoretical considerations and corresponding numerical simulations are needed to identify well-suited initial parameters for experimental studies. We present the theoretical analysis of a hydrogel in a frequently used electrical stimulation device for cartilage regeneration and tissue engineering. By means of equivalent circuits, finite element analysis, and uncertainty quantification, we elucidate the influence of the geometric and dielectric properties of cell-seeded hydrogels on the capacitive-coupling electrical field stimulation. Moreover, we discuss the possibility of cellular organisation inside the hydrogel due to forces generated by the external electric field. The introduced methodology is easily reusable by other researchers and allows to directly develop novel electrical stimulation study designs. Thus, this study paves the way for the design of future experimental studies using electrically conductive hydrogels and electrical stimulation for tissue engineering.
CRIS-Team Scopus Importer:2020-11-06
Keywords: Biomaterial scaffolds; Capacitive coupling; Computational modelling; Electrical stimulation; Electrically conductive hydrogels; Finite element analysis; Scaffold; Tissue engineering; Uncertainty quantification

Oberflächenmodifikation von bioaktiven Glasstützstrukturen - Balasubramanian, Preethi (2016)
Bioactive glasses (BGs) continue to attract interest as promising materials for bone regeneration. In the broad family of BGs, boron containing systems, including B-doped silicate, borosilicate glasses and borate glasses, are being increasingly considered due to their attractive osteogenic and neovascularization properties. In this work, a new series of BGs based on the 13-93 composition (SiO2-CaO-Na2O-P2O5-K2O-MgO-B2O3) was prepared and three-dimensional scaffolds were produced by the polymer replica technique. The compressive strength of these scaffolds was found to be significantly higher than that of standard 45S5 Bioglass® scaffolds which is related to the higher densification rate of struts achieved by viscous flow during the sintering process. In vitro dissolution studies in cell culture medium were carried out over a period of 14 days and the formation of hydroxyapatite (HA) was confirmed using different characterization techniques such as Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The boron-based scaffolds immersed in cell culture medium exhibited a moderate release of B and Si ions which was measured using Inductively Coupled Plasma-Optical emission analyses. The effects of the ionic dissolution products (IDPs) of the boron-based BG scaffolds on mouse bone marrow stromal cells (ST2 cells) in vitro were ascertained, using an angiogenesis assay. The expression and secretion of angiogenic growth factor, vascular endothelial growth factor (VEGF) from ST2 cells were measured quantitatively using the VEGF ELISA Kit. Cellular response was found to be dependent on the boron content and the B release profile from the glasses corresponded to the positive/negative influence in their biological activity. Functionalizing the surfaces of these BG scaffolds with biologically active molecules or enzymes is a suitable strategy to enhance both the inorganic and biological responses of the biomaterial and to stimulate physiological tissue regeneration. Alkaline Phosphatase (ALP) is a metalloenzyme involved, significantly, in osteogenesis and is highly expressed in mineralized tissue cells. Silanization was performed, followed by ALP grafting on the surface of the BG scaffolds, which was confirmed by FTIR and enzymatic activity test, respectively. The ability of the boron-containing BG scaffolds, with and without ALP grafting, to stimulate VEGF from ST2 cells was determined. An in vitro osteogenic differentiation experiment, with and without the presence of osteogenic stimulating agents, was executed over a period of 14 days. It was determined that the ALP grafted to the surface of boron-containing scaffolds equated the performance of an osteogenic stimulating agent during the differentiation of ST2 cells. Cell viability and proliferation were determined using mitochondrial & LDH activity and BrdU (calorimetric) assay, respectively. Specific ALP activity and a mineralization assay revealed that the ALP-functionalized boron-containing scaffolds possess excellent capabilities to differentiate stromal cells into osteoblast-like phenotype. A preliminary subcutaneous implantation study in rats was carried out (by collaborators) to evaluate the performance of ALP-functionalized scaffolds in vivo. The influence of an enzyme (ALP) was established, in terms of ion release kinetics, directing better cell-matrix interactions, osteogenic differentiation and angiogenic potential, for bone regeneration applications. In summary, the combination of boron-containing BG scaffolds with the enzyme ALP has facilitated the inception of a promising strategy to enhance bone healing and regeneration.
Keywords: bioactive glasses; borate glass; tissue engineering; bone regeneration; borosilicate glass; angiogenesis

Oberflächenmodifizierung von bioabbaubaren metallischen Materialien mit Fokus auf Magnesium und Eisen - Yang, Yuyun (2017)
Biodegradable metallic implants are being considered as promising candidates to replace non-degradable ones for applications such as bone plates, screw fixations, and vascular stents in surgical applications. The advantage of biodegradable implants is the avoidance of the second operation to remove non-degradable inert devices, which raises the cost and causes pain for patients. Bioabsorbable implants should be designed to be completely degraded with a proper host response after tissues heal in vivo. Due to their attractive mechanical properties, biocompatibility and biodegradability, magnesium and iron are regarded as suitable biodegradable substitutes to replace permanent implants and devices. In principle, a controllable degradation rate should be achieved as this is a key requirement for degradable metallic biomaterials. Regarding the degradation rate, magnesium and iron present different challenges for biomedical application. For example, the high dissolution rate of magnesium in biological environment leading to severe pH changes and hydrogen evolution near implantation sites has largely inhibited its biomedical application (including also Mg alloys). On the contrary, iron shows a too slow degradation rate as a possible biodegradable material. Surface treatments and modifications are considered to be relative low-cost and high-efficient ways to obtain coating systems which can be used to tailor the degradation rate of magnesium and iron. Besides controlling the dissolution of bulk substrates, surface coating systems could be multi-functionalized, for example by introducing bioactive particles to improve bioactivity (e.g. bone bonding ability) and for drug delivery. In the present work, protective coating systems on magnesium and nanostructured oxide layers on iron were investigated, respectively.Polycaprolactone (PCL)-based and polyetherimide (PEI)-based composite coating systems were applied on pure magnesium by spin coating method. Selective concentrations of nano-scaled bioactive glass particles (nBG) were added to PCL coatings to investigate the influence of nBG on coating properties. It was found that nBG addition in PCL increases the degradation of PCL in physiological solution and the addition of nBG facilitates the formation of calcium phosphates on the composite surface upon 7 days of immersion in simulated body fluid (SBF). Further, different amounts of copper (Cu)-containing bioactive glass nanoparticles (Cu-BGNs) were added to the optimized PCL coatings and the influence of Cu-BGNs addition on the coating performance was investigated. Increasing concentration of Cu-BGNs was found to lead to slightly decreasing wettability and anti-corrosion properties of Cu-BGN/PCL composite coating. Higher Cu-BGNs content in the coatings facilitates more calcium phosphate formation after 7 days of immersion in Dulbecco’s modified Eagle’s medium (DMEM). The growth of S.carnosus and E. coli was inhibited by Cu2+ ions released from Cu-BGN coatings highlighting the antibacterial capability of the coatings. Besides, cytocompatibility experiments showed that the viability and proliferation of MG-63 cells on Cu-BGN/PCL coatings significantly increased compared to values for pure magnesium; however, the addition increase of Cu-BGNs showed a slight decrease of cell proliferation and cell activity.In addition, PEI coatings were obtained on pure magnesium, which was pretreated with di-ammonium hydrogen phosphate (DAHP) by hydrothermal method. The DAHP/PEI layered coatings dramatically improved the corrosion resistance of magnesium and the coatings showed no visible changes after 3 days of immersion in DMEM. In vitro cytocompatibility assessment demonstrated that MG-63 cells on DAHP/PEI possess the high viability, proliferation rate and lactate dehydrogenase (LDH) activity.Furthermore, a hybrid of metallic iron in a layered composite structure on magnesium was studied to combine the merits of both metals. A single-step dip coating method was employed to prepare the layered composite material. Morphology, composition, crystal structure and corrosion behavior of the Mg/Fe sheet were assessed. The Mg/Fe layered composite sheet is composed of the magnesium substrate, a 1-2 µm metallic iron coating, and a “pompon-like” Mg(OH)2/MgO top layer. Long-term open-circuit potential measurements revealed that the Mg/Fe sheet samples exhibit a “self-healing” effect in DMEM.In the last part of the work, iron oxide nanostructured arrays were successfully fabricated on pure iron substrates by anodic oxidization process. The oxide layer is considered an activated surface to accelerate the degradation rate of iron substrates. Iron oxide nanostructured arrays in porous and tubular structures were produced and studied by electrochemical and immersion tests, to reveal details of the degradation process. Cytotoxicity of iron nano arrays was assessed by indirect test using MG-63 cells. No cytotoxicity was found in all extracts from iron oxide nanostructured arrays after 2d culture in DMEM.In summary, different surface modifications were designed and applied on biodegradable magnesium and iron substrates to achieve different goals. Regarding magnesium, PCL-based (with nBG/Cu-BGN addition) and PEI-based (DAHP pre-coating) composite coatings with suitable barrier properties and cell compatibility are promising examples of the success of the methodology developed for the surface treatment of biodegradable magnesium implants and devices. Furthermore, for iron biomaterials, developing iron nanoarrays on iron substrates showed good cytocompatibility suggesting the potential of using iron as a biodegradable material in the biomedical field. The results of the present research project are thus relevant to broaden biomedical applications of pure magnesium and iron.; In neueren Untersuchungen werden biodegradierbare, metallische Implantate als vielversprechende Ersatzkandidaten für nicht-degradierbare Implantate, wie z.B. Knochenplatten, Schraubenfixierung und vaskuläre Stents, in chirurgischen Anwendungen angesehen. Der Vorteil der biodegradierbaren Implantate ist die Vermeidung einer zweiten Operation zur Entfernung von nicht-abbaubaren inerten Instrumenten, welches sowohl die Kosten, als auch das Trauma für Patienten erhöht. Die bioabsorbierbaren Implantate sollten so konstruiert sein, dass sie sich mit einer angemessenen Wirtsreaktion nach der Gewebeheilung in vivo vollständig auflösen. Auf Grund der passenden mechanischen Eigenschaften, der Biokompatibilität und Bioabbaubarkeit, werden beide, Magnesium und Eisen, als geeigneter biodegradierbarer Ersatz für permanente Implantate und Instrumente angesehen. Prinzipiell soll eine kontrollierbare Abbaurate erreicht werden, da dies die Hauptanforderung für degradierbare, metallische Biomaterialien ist. Bezüglich der Abbaurate präsentieren Magnesium und Eisen verschiedene Herausforderungen in der Anwendung. Zum Beispiel führt die schnelle Auflösungsrate von Magnesium in biologischer Umgebung zu hohen pH Änderungen und zur Wasserstofffreisetzung nahe des Implantationsortes, welches die biomedizinischen Anwendungen zum Großteil verhindert (einschließlich der Mg-Legierungen). Im Gegensatz dazu zeigt Eisen eine zu langsame Abbaubarkeit, um als mögliches biodegradierbares Material zu gelten. Oberflächenbehandlungen und Modifizierungen werden als relativ kostengeringe und effiziente Wege angesehen, um Beschichtungssysteme zu erhalten, die verwendet werden können, um die Auflösung von Magnesium und Eisen zu beeinflussen. Neben der kontrollierten Auflösung des Bulk Materials, können Oberflächenbeschichtungssystem multifunktionalisiert werden, z.B. mit der Einführung von bioaktiven Partikeln um die Bioaktivität (Knochenanbindungsfähigkeit) und die Wirkstofffreisetzung zu verbessern. In dieser Arbeit werden die schützenden Beschichtungssysteme auf Magnesium und nanostrukturierte Oxidschichten auf Eisen untersucht.Polycaprolacton (PCL) und Polyetherimid (PEI)-basierte Kompositsysteme wurden auf reines Magnesium mittels Rotationsbeschichtung aufgebacht. Gleiche Mengen von nano-skalierten bioaktiven Glaspartikeln (nBG) wurden in verschiedenen Konzentrationen den PCL Beschichtungen zugegeben, um den Einfluss von nBG zu untersuchen und die optimale PCL Konzentration zu bestimmen. Es ergab sich, dass die Zugabe von nBG zu PCL die Abbaubarkeit von PCL in physiologischer Lösung erhöht und die Zugabe von nBG die Bildung von Calciumphosphaten auf der Kompositoberfläche innerhalb 7 Tage Immersionstest in simulierter Körperflüssigkeit (SBF) fördert. Weiterhin wurden unterschiedliche Mengen von Kupfer(Cu)-enthaltenden bioaktiven Glas-Nanopartikeln (Cu-BGNs) in die konzentrationsoptimierte PCL Beschichtung gegeben und der Einfluss der Cu-BGNs Zugabe auf das Beschichtungsverhalten untersucht. Steigende Konzentrationen von Cu-BGNs führten zu einer leichten Absenkung der Wasserbenetzbarkeit und der Anti-Korrosionseigenschaften der Cu-BGN/PCL Kompositbeschichtungen. Im Gegensatz dazu förderte ein höherer Cu-BGNs Anteil in der Beschichtung die Formierung von Calciumphosphaten nach 7 Tagen Immersionstest in Dulbecco’s modified Eagle’s medium DMEM. Der Wachstum von S. carnosus und E. coli war durch die Cu2+ Ionen Freigabe der Cu-BGNs Beschichtungen unterdrückt. Zusätzlich zeigten die Viabilität und Proliferation von MG-63 Zellen auf Cu-BGN/PCL Beschichtungen einen signifikanten Anstieg im Vergleich zu den Werten von reinem Magnesium; nichtsdestotrotz zeigte die ansteigende Zugabe von Cu-BGNs eine geringe Reduzierung der Zellproliferation und Zellaktivität.Zusätzlich wurden PEI Beschichtungen auf reinem Magnesium erhalten, welches mit Diammoniumhydrogenphosphat (DAHP) durch hydrothermale Methoden vorbehandelt wurde. Die DAHP/PEI überlagert Beschichtung verbesserte den Korrosionswiderstand von Magnesium erheblich und die Beschichtung zeigte keine deutlich sichtbaren Veränderungen nach 3 Tagen Immersionstest in DMEM. In vitro Zellkompatibilitätsmessungen zeigten, dass MG-63 Zellen auf DAHP/PEI eine hohe Viabilität, Proliferationsrate und Laktatdehydrogenase Aktivität (LDH) besitzen.Weiterhin wurde ein Hybrid aus metallischen Ionen in Schichtkompositen auf Magnesium untersucht, um die Vorteile beider Metalle zu verbinden. Eine Einzelschritt-Tauchbeschichtung wurde verwendet, um ein Schichtkompositmaterial zu erhalten. Die Morphologie, Komposition, Kristallstruktur und das Korrosionsverhalten auf dem Mg/Fe Blech wurde mittels Rasterelektronenmikroskopie (REM), energiedispersiver Röntgenspektroskopie (EDS), Röntgenbeugung (XRD) und elektrochemischen Messungen untersucht. Das Mg/Fe Schichtkompositblech bestand aus einem Magnesiumsubstrat, einer 1-2 µm dicken metallischen Eisenbeschichtung und einer Pompon-ähnlichen Mg(OH)2/MgO Oberfläche. Langzeit Leerlaufpotentialmessungen zeigten, dass Mg/Fe Blechproben einen „selbst-heilenden“ Effekt in (DMEM) besitzen.Im letzten Teil dieser Arbeit wurden Eisenoxidnanostrukturen erfolgreich durch anodische Oxidationsprozesse auf reinen Eisensubstraten hergestellt. Die Oxidschicht wird als eine aktivierte Oberfläche auf dem Eisen betrachtet, welche die Auflösungsrate von Eisensubstraten beschleunigt. Diese Eisenoxidnanostrukturen in porösen und tubularen Strukturen wurden hergestellt und mittels elektrochemischer Test und Immersionsversuchen untersucht, um die Details des Degradationsprozesses zu offenbaren. Zytotoxizität der Eisennanostrukturen wurde durch indirekte Zellversuche mit MG-63 Zellen getestet. Es zeigt sich, dass keine Zytotoxizität in keiner der Extrakte von den Eisenoxidnanostrukturen nach 2 Tagen Inkubation in DMEM gefunden werden konnte.Zusammenfassend lässt sich sagen, dass unterschiedliche Oberflächenmodifikationen entwickelt und auf bioabbaubaren Magnesium- und Eisensubstraten angewendet wurden, um verschiedene Ziele zu erreichen. Bezüglich der magnesiumhaltigen Biomaterialien sind PCL- (mit nBG/Cu-BGN Zugabe) und PEI- (DAHP Vorbehandlung)basierte Kompositbeschichtungen mit geeigneten begrenzenden Eigenschaften und Zellkompatibilität erfolgsversprechende Beispiele der entwickelten Methode für die Oberflächenbehandlung von bioabbaubaren Magnesium Implantaten und Instrumenten. Für eisenhaltige Biomaterialien konnte die Entwicklung von Eisennanoanordnungen auf Eisensubstraten gute Zytokompatibilität zeigen, welches das Potential von Eisen als bioabbaubares Material hervorhebt. Aus diesem Grund wird die Erforschung von verschiedenen Arten der Oberflächenmodifikation, welche in dieser Arbeit präsentiert werden, als eine Erweiterung der biomedizinischen Anwendungen auf bioabbaubares reines Magnesium und reines Eisen angesehen.
Keywords: Magnesium; Iron; Biocompatibility; Biodegradability

On-chip fabrication and in-flow 3D-printing of microgel constructs: from chip to scaffold materials in one integral process - Reineke, Benjamin; Paulus, Ilona; Löffelsend, Sophia; Yu, Chien Hsin; Vinogradov, Dmitrii; Meyer, Anna; Hazur, Jonas; Röder, Jonas; Vollmer, Madita; Tamgüney, Gültekin; Hauschild, Stephan; Boccaccini, Aldo R.; et al. (Biofabrication, 2024)
Bioprinting has evolved into a thriving technology for the fabrication of cell-laden scaffolds. Bioinks are the most critical component for bioprinting. Recently, microgels have been introduced as a very promising bioink, enabling cell protection and the control of the cellular microenvironment. However, the fabrication of the bioinks involves the microfluidic production of the microgels, with a subsequent multistep process to obtain the bioink, which so far has limited its application potential. Here we introduce a direct coupling of microfluidics and 3D-printing for the continuous microfluidic production of microgels with direct in-flow printing into stable scaffolds. The 3D-channel design of the microfluidic chip provides access to different hydrodynamic microdroplet formation regimes to cover a broad range of droplet and microgel diameters. After exiting a microtubing the produced microgels are hydrodynamically jammed into thin microgel filaments for direct 3D-printing into two- and three-dimensional scaffolds. The methodology enables the continuous on-chip encapsulation of cells into monodisperse microdroplets with subsequent in-flow cross-linking to produce cell-laden microgels. The method is demonstrated for different cross-linking methods and cell lines. This advancement will enable a direct coupling of microfluidics and 3D-bioprinting for scaffold fabrication.
CRIS-Team Scopus Importer:2024-04-05
Keywords: 3D-printing; microfluidics; microgels

On the reproducibility of extrusion-based bioprinting: round robin study on standardization in the field - Grijalva Garces, David; Strauß, Svenja; Gretzinger, Sarah; Schmieg, Barbara; Jüngst, Tomasz; Groll, Jürgen; Meinel, Lorenz; Schmidt, Isabelle; Hartmann, Hanna; Schenke-Layland, Katja; Brandt, Nico; Selzer, Michael; et al. (Biofabrication, 2023)
The outcome of three-dimensional (3D) bioprinting heavily depends, amongst others, on the interaction between the developed bioink, the printing process, and the printing equipment. However, if this interplay is ensured, bioprinting promises unmatched possibilities in the health care area. To pave the way for comparing newly developed biomaterials, clinical studies, and medical applications (i.e. printed organs, patient-specific tissues), there is a great need for standardization of manufacturing methods in order to enable technology transfers. Despite the importance of such standardization, there is currently a tremendous lack of empirical data that examines the reproducibility and robustness of production in more than one location at a time. In this work, we present data derived from a round robin test for extrusion-based 3D printing performance comprising 12 different academic laboratories throughout Germany and analyze the respective prints using automated image analysis (IA) in three independent academic groups. The fabrication of objects from polymer solutions was standardized as much as currently possible to allow studying the comparability of results from different laboratories. This study has led to the conclusion that current standardization conditions still leave room for the intervention of operators due to missing automation of the equipment. This affects significantly the reproducibility and comparability of bioprinting experiments in multiple laboratories. Nevertheless, automated IA proved to be a suitable methodology for quality assurance as three independently developed workflows achieved similar results. Moreover, the extracted data describing geometric features showed how the function of printers affects the quality of the printed object. A significant step toward standardization of the process was made as an infrastructure for distribution of material and methods, as well as for data transfer and storage was successfully established.
CRIS-Team Scopus Importer:2023-10-20
Keywords: 3D printing; bioink; extrusion-based bioprinting; reproducibility; round robin; technology transfer

Optically-transparent oxide fibre-reinforced glass matrix composites - Desimone, Deborah; Dlouhy, Ivo; Lee, William E.; Koch, Dietmar; Horvath, Jürgen; Boccaccini, Aldo R. (Journal of Non-Crystalline Solids, 2010)
The development of 'optomechanical composites', based on glass matrices reinforced with continuous oxide fibre bundles (Nextel™) or filaments (sapphire) is described. The fibres were arranged unidirectionally between soda-lime silicate or borosilicate glass slides, and heat-treated to achieve densification by viscous flow of the glass matrix between the fibres. Small decreases in light transmittance (up to approximately 20%) upon introduction of fibres indicated that the composites are promising materials for use in optomechanical applications, where high transparency or translucency is required, in addition to improved fracture resistance. Fibre pull-out and crack deflection were identified at fibre/matrix interfaces, and a crack bridging effect was observed, with fibres holding the glass pieces together, thus preventing catastrophic failure. A relatively low fibre/matrix interfacial sliding resistance was measured by the fibre push-in test, although flexural strength measurements indicated the need to improve interfacial bonding. For this purpose, a tetragonal zirconia interfacial layer was introduced by sol-gel dip-coating of the fibres, to modify the fibre/matrix bonding, providing weaker interfaces that facilitate the occurrence of toughening mechanisms. © 2010 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.optica
Keywords: Fracture toughness; Glass matrix composites; Light transmittance; Optomechanical

Optimization of cell seeding on electrospun PCL-silk fibroin scaffolds - Singh, Raminder; Eitler, David; Morelle, René; Friedrich, Ralf P.; Dietel, Barbara; Alexiou, Christoph; Boccaccini, Aldo R.; Liverani, Liliana; Cicha, Iwona (European Polymer Journal, 2020)
The availability of cell growth-supporting materials for regenerative medicine is limited. Here, we aimed to improve the attachment and growth of endothelial cells (HUVECs) and fibroblasts on electrospun poly(ε-caprolactone) (PCL) mats with different fiber diameters and on newly-established PCL and silk fibroin (PCL/SF) blended fibers obtained by using benign solvents (mixture of acetic acid and formic acid) for electrospinning. PCL mats were produced in two different average fiber diameters, namely micro and nano range. The electrospinning method was optimized to produce PCL/SF blended fibers. Morphology (F-actin), viability (calcein) and metabolic activity (WST-8 assay) of HUVECs and fibroblasts cultured in 2D on the mats of different fiber size and composition were compared. Subsequently, cylindrical PCL/SF scaffolds were produced and colonized with cells using 3D radial magnetic cell seeding. Both PCL and PCL/SF nanofibers provided better support for initial cell adhesion (day 1) compared with PCL microfibers. At day 7, the highest metabolic activity in HUVECs and fibroblasts was observed on PCL/SF mats. Microscopic studies confirmed that on day 7, the best support for cell growth was observed on PCL/SF. Tubular PCL/SF scaffolds were successfully colonized using magnetic nanoparticles and 3D radial magnetic cell seeding. Taken together, the fibers obtained by blending SF with PCL combine the mechanical benefits of PCL with improved biological functionality of SF. Electrospun PCL/SF nanofibers represent a promising material to produce both flat and 3D structures with potential for enhanced cell attachment and tissue regeneration.
CRIS-Team Scopus Importer:2020-06-26
Keywords: Benign solvents; Electrospinning; Magnetic cell seeding; Nanofibers; Poly(ε-caprolactone); Silk fibroin

Optimization of Porcine Ovarian Follicle Isolation Methods for Better Developmental Potential - Fattahi, Amir; Liverani, Liliana; Dittrich, Ralf; Hoffmann, Inge; Boccaccini, Aldo R.; Beckmann, Matthias; Bleisinger, Nathalie (Tissue Engineering - Part A, 2020)
In the present study, we present a comparative analysis among the outputs of porcine follicle isolation using either mechanical technique alone or in combination with enzymes, proposing an optimized protocol useful for all further applications related to folliclein vitrogrowth and reproductive tissue engineering. The porcine follicles were isolated using mechanical technique alone (hand blender and scalpels) or in combination with collagenase or Liberase Dispase High (DH) at different doses applying different protocols. Finally, the number, morphology, and stage of isolated follicles were compared between the protocols. Moreover, the follicle viability (live/dead assay) and morphology (rhodamine phalloidin and 4 ',6-diamidino-2-phenylindole staining and scanning electron microscopy analysis) were evaluated after 10 days of culture. We found an optimum protocol for intact follicle isolation using the mechanical technique in combination with enzymes at a concentration of 0.5 mg/mL. However, the number of total isolated follicles and primordial follicles was significantly higher when collagenase was used compared to Liberase DH (p < 0.05), while Liberase DH could isolate a significantly higher percentage of preantral follicles. After 10 days of culture, the morphology and health status of follicles were statistically higher when Liberase DH was used in comparison with collagenase. Moreover, on the follicles extracted with Liberase DH, it was possible to observe theca cells covering part of the follicle surface. In conclusion, we demonstrated that the intact primary or secondary follicles could not be obtained using only mechanical methods, which led to the isolation of denuded oocytes and dramatically damaged follicles. We concluded that the collagenase-based follicle isolation could negatively affect the morphology and developmental potential of the follicles. Moreover, the incubation of ovarian cortex tissues with Liberase DH solution is an optimized protocol for porcine ovarian follicle isolation with developmental competence.
CRIS-Team WoS Importer:2020-07-24

Optimization of process parameters for the synthesis of class F fly ash-based geopolymer binders - Addis, Lulseged Belay; Sendekie, Zenamarkos Bantie; Habtu, Nigus Gabbiye; de Ligny, Dominique; Roether, Judith; Boccaccini, Aldo R. (Journal of Cleaner Production, 2023)
The Taguchi optimization approach was applied in this study to identify the optimal mix ratios for the production of geopolymer paste that uses fly ash as an aluminosilicate precursor. The method allows for probing the combined effect of selected process parameters on the output response with the least number of experiments possible, thereby reducing overall process time, cost, and effort. The compressive and splitting tensile strength values of the geopolymer paste specimens were explored in terms of alkali activator to binder ratio, NaOH concentration, Na2SiO3 to NaOH mass ratio, and standing time. A total of sixteen different proportions of mixtures were prepared, and the mechanical strengths of the specimens were evaluated using a universal testing machine. XRD and SEM analyses were used to examine the microstructures of the fly ash and the proposed optimized geopolymer paste. Results showed that a combination of alkali activator to binder ratio of 0.46, NaOH concentration of 14 M, Na2SiO3 to NaOH mass ratio of 1.5, and standing time of 72 h were found to be the best parameter settings yielding the highest strength of the paste specimens. The maximum compressive and splitting tensile strengths were 24.96 and 4.40 MPa, respectively, at the corresponding optimal values of the parameters. The apparent density of the specimens at these optimal conditions was determined to be 1835 kg/m3. From ANOVA results, it was observed that standing time and NaOH concentration had a significant influence on compressive and splitting tensile strength values, respectively. Based on the confirmation test, a variation of 4.1% and 2.2% in compressive and splitting tensile strengths, respectively, were observed as a result of extraneous variables.
CRIS-Team Scopus Importer:2024-12-16
Keywords: Compressive strength; Fly ash; Splitting tensile strength; Taguchi optimization approach

Optimization of the mechanical properties of calcium phosphate/multi-walled carbon nanotubes/bovine serum albumin composites using response surface methodology - Low, Kah Ling; Tan, Soon Huat; Zein, Sharif Hussein Sharif; Mcphail, David S.; Boccaccini, Aldo R. (Materials & Design, 2011)
Response surface methodology (RSM) coupled with the central composite design (CCD) was used to optimize the mechanical properties of calcium phosphate cement/multi-walled carbon nanotubes/bovine serum albumin (CPC/MWCNTs/BSA) composites. In this study, CPC composites were reinforced by multi-walled carbon nanotubes (MWCNTs) and bovine serum albumin (BSA) in order to induce high mechanical properties in the CPC/MWCNTs/BSA system. The effect of various process parameters on the compressive strength of CPC/MWCNTs/BSA composites was studied using design of experiments (DOE). The process parameters studied were: wt.% of MWCNTs (0.2-0.5 wt.%), wt.% of BSA (5-15. wt.%) and type of MWCNTs (e.g. as-pristine MWCNT (MWCNT-AP), hydroxyl group functionalized MWCNT (MWCNT-OH) and carboxyl group functionalized MWCNT (MWCNT-COOH)). Based on the CCD, a quadratic model was obtained to correlate the process parameters to the compressive strength of CPC/MWCNTs/BSA composites. From the analysis of variance (ANOVA), the most significant factor affected on the experimental design response was identified. The predicted compressive strength after process optimization was found to agree well with the experimental value. The results revealed that at 0.5. wt.% of MWCNT-OH and 15. wt.% of BSA, the highest compressive strength of 14. MPa was obtained. © 2011 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.optimi
Keywords: A. Composites; E. Mechanical; G. Scanning electron microscopy

Optimizing α-tricalcium phosphate bone cement composite formulations: The critical role of bioactive glass particle size - Demir, Öznur; Oselska, Estere; Bertins, Maris; Viksna, Arturs; Boccaccini, Aldo R.; Loca, Dagnija (Materials & Design, 2024)
Calcium phosphate cements (CPCs) have been extensively utilized as bone grafting material due to their inherent osteoconductive properties, although they often lacked sufficient biological performance for effective bone healing at the defect site. Incorporating mesoporous bioactive glass (MBG) into CPCs offers a solution by improving porosity, promoting degradation and increasing the available surface area. In the scope of this study, we integrated MBG into CPCs and assessed the impact of varying MBG particle sizes (<20 µm, <38 µm, <100 µm) on the setting characteristics, microstructure, mechanical strength, and preliminary cell response of CPCs. Investigations revealed that < 20 µm MBG particles significantly improved the setting characteristics and compressive strength of CPCs, while < 38 µm particles promoted degradation and ion release, facilitating apatite formation. MBG incorporation was found to promote microstructural homogeneity and facilitate apatite formation, with particle size directly affecting these outcomes. Biocompatibility assessments indicated no cytotoxic effects, supported by the favorable cellular responses (> 92 % viability compared to control group). These findings underscore the critical impact of MBG particle size on developing advanced CPCs for biomedical applications, guiding future design and optimization strategies.
CRIS-Team Scopus Importer:2025-02-04
Keywords: Bioactive glass; Bone cements; Bone regeneration; Calcium phosphate; Mesoporous; Particle size

Organic solvent-free synthesis of dendritic mesoporous bioactive glass nanoparticles with remineralization capability - Han, Xiao; Erkan, Aleyna; Xu, Zhiyan; Chen, Yaming; Boccaccini, Aldo R.; Zheng, Kai (Materials Letters, 2022)
Dendritic mesoporous bioactive glass nanoparticles (DMBGNs) are emerging biomaterials for various biomedical applications. However, their synthesis usually involves extensive volatile organic solvents, causing significant environmental and economic issues. We report an organic solvent-free strategy to produce DMBGNs, in which cationic and anionic surfactants were used as dual templates free of organic solvents to assemble silicate nanoparticles before incorporation of Ca by impregnation. The Ca incorporation did not affect the dendritic mesoporous structure of the nanoparticles. DMBGNs exhibited remineralization capacity as evidenced by hydroxyapatite (HA) formation after soaking in simulated body fluid (SBF). The results indicate the feasibility of the proposed organic solvent-free, two-step strategy for producing DMBGNs highlighting also the great potential of DMBGNs as remineralization agents.
CRIS-Team Scopus Importer:2022-05-20
Keywords: Bioactive glasses; Biomaterials; Green synthesis; Nanoparticles; Remineralization

Osteoblast and osteoclast responses to A/B type carbonate-substituted hydroxyapatite ceramics for bone regeneration - Germaini, Marie-Michele; Detsch, Rainer; Grünewald, Alina; Magnaudeix, Amandine; Lalloue, Fabrice; Boccaccini, Aldo R.; Champion, Eric (Biomedical Materials, 2017)
Keywords: Bioceramics; bone graft susbtitutes; carbonated hydroxyapatite; cell culture; osteoblasts; osteoclasts

Osteochondral tissue engineering: scaffolds, stem cells and applications - Nooeaid, Patcharakamon; Salih, Vehid; Beier, Justus; Boccaccini, Aldo R. (Journal of Cellular and Molecular Medicine, 2012)
Osteochondral tissue engineering has shown an increasing development to provide suitable strategies for the regeneration of damaged cartilage and underlying subchondral bone tissue. For reasons of the limitation in the capacity of articular cartilage to self-repair, it is essential to develop approaches based on suitable scaffolds made of appropriate engineered biomaterials. The combination of biodegradable polymers and bioactive ceramics in a variety of composite structures is promising in this area, whereby the fabrication methods, associated cells and signalling factors determine the success of the strategies. The objective of this review is to present and discuss approaches being proposed in osteochondral tissue engineering, which are focused on the application of various materials forming bilayered composite scaffolds, including polymers and ceramics, discussing the variety of scaffold designs and fabrication methods being developed. Additionally, cell sources and biological protein incorporation methods are discussed, addressing their interaction with scaffolds and highlighting the potential for creating a new generation of bilayered composite scaffolds that can mimic the native interfacial tissue properties, and are able to adapt to the biological environment. © 2012 The Authors Journal of Cellular and Molecular Medicine © 2012 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.osteoc
Keywords: Bilayered scaffolds; Clinical relevance; Composites; Osteochondral tissue engineering; Scaffold designs; Scaffold fabrication

Osteogenic and angiogenic potential of molybdenum-containing mesoporous bioactive glass nanoparticles: An ionic approach to bone tissue engineering - Moll, M.; Scheurle, A.; Nawaz, Qaisar; Walker, T.; Kunisch, E.; Renkawitz, T.; Boccaccini, Aldo R.; Westhauser, F. (Journal of Trace Elements in Medicine and Biology, 2024)
Biomaterials intended for application in bone tissue engineering (BTE) ideally stimulate osteogenesis and angiogenesis simultaneously, as both mechanisms are of critical importance for successful bone regeneration. Mesoporous bioactive glass nanoparticles (MBGNs) can be tailored towards specific biological needs, for example by addition of ions like Molybdenum (Mo). While Mo has been shown to enhance osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (BMSCs) as well as their ability to form and mature a primitive osseous extracellular matrix (ECM), there are contradictory findings regarding its impact on angiogenesis. In this study, the effects of Mo-MBGNs (mol%: 70 SiO2, 25 CaO, 5 MoO3) on viability, proliferation, osteogenic differentiation, ECM formation and angiogenic response of BMSCs were compared to undoped MBGNs (in mol%: 70 SiO2, 30 CaO) and a control group of BMSCs. Furthermore, a human umbilical vein endothelial cells tube formation assay and a chorioallantoic membrane-assay using fertilized chicken eggs were used to analyze angiogenic properties. Mo-MBGNs were cytocompatible and promoted the proliferation of BMSCs. Furthermore, Mo-MBGNs showed promising osteogenic properties as they enhanced osteogenic differentiation, ECM formation and maturation as well as the gene expression and protein production of relevant osteogenic factors in BMSCs. However, despite the promising outcome on osteogenic properties, the addition of Mo to MBGNs resulted in anti-angiogenic effects. Due to the high relevance of vascularization in-vivo, the anti-angiogenic properties of Mo-MBGNs might hamper their osteogenic properties and therefore might restrict their performance in BTE applications. These limitations can be overcome by the addition of ions with distinct pro-angiogenic properties to the Mo-MBGNs-composition. Due to their promising osteogenic properties, Mo-MBGNs constitute a suitable basis for further research in the field of ionic (growth factor free) BTE.
CRIS-Team Scopus Importer:2024-09-13
Keywords: Angiogenesis; Bioactive glass; Mesoporous bioactive glass nanoparticles; Molybdenum; Osteogenic differentiation

Osteogenic differentiation of human dental pulp stromal cells on 45S5 bioglass® based scaffolds in vitro and in vivo - El-Gendy, Reem; Yang, Xuebin B.; Newby, Phillipa J.; Boccaccini, Aldo R.; Kirkham, Jennifer (Tissue Engineering - Part A, 2013)
The increasing clinical demand for bone substitutes has driven significant progress in cell-based therapies for bone tissue engineering. The underpinning goals for success are to identify the most appropriate cell source and to provide three-dimensional (3D) scaffolds that support cell growth and enhance osteogenic potential. In this study, human dental pulp stromal cells (HDPSCs) were cultured under basal or osteogenic conditions either in monolayers or on 3D Bioglass scaffolds in vitro for 2 or 4 weeks. Cell-scaffold constructs were also implanted intraperitoneally in nude mice for 8 weeks. Osteogenic potential was assessed using quantitative real-time polymerase chain reaction and histological/immunohistochemical assays. In monolayer culture, osteoinductive conditions enhanced HDPSC expression of osteogenic gene markers (COL1A1, RUNX2, OC, and/or OCN) compared with basal conditions while culture of HDPSCs on 3D scaffolds promoted osteogenic gene expression compared with monolayer culture under both basal and osteogenic conditions. These results were confirmed using histological and immunohistochemical analyses. In vivo implantation of the HDPSC 3D Bioglass constructs showed evidence of sporadic woven bone-like spicules and calcified tissue. In conclusion, this study has demonstrated the potential of using a combination of HDPSCs with 3D 45S5 Bioglass scaffolds to promote bone-like tissue formation in vitro and in vivo, offering a promising approach for clinical bone repair and regeneration. © Copyright 2013, Mary Ann Liebert, Inc. 2013.

Osteogenic differentiation of umbilical cord and adipose derived stem cells onto highly porous 45S5 Bioglass®-based scaffolds - Detsch, Rainer; Alles, Sonja; Hum, Jasmin; Westenberger, Peter; Sieker, Frank; Heusinger, Dominik; Kasper, Cornelia; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2015)
In the context of bone tissue engineering (BTE), combinations of bioactive scaffolds with living cells are investigated to optimally yield functional bone tissue for implantation purposes. Bioactive glasses are a class of highly bioactive, inorganic materials with broad application potential in BTE strategies. The aim of this study was to evaluate bioactive glass (45S5 Bioglass®) samples of composition: 45 SiO, 24.5 CaO, 24.5 NaO, and 6 PO (in wt%) as scaffold materials for mesenchymal stem cells (MSC). Pore architecture of the scaffolds as well as cell behavior in the three-dimensional environment was evaluated by several methods. Investigations concerned the osteogenic cell attachment, growth and differentiation of adipose tissue derived MSC (adMSC) compared with MSC from human full term umbilical cord tissues (ucMSC) on porous Bioglass® -based scaffolds over a cultivation period of 5 weeks. Differences in lineage-specific osteogenic differentiation of adMSC and ucMSC on Bioglass® samples were demonstrated. The investigation led to positive results in terms of cell attachment, proliferation, and differentiation of MSC onto Bioglass® -based scaffolds confirming the relevance of these matrices for BTE applications.
Keywords: 45S5 Bioglass®; Bone tissue engineering; Mesenchymal stem cells; Scaffolds

Osteogenic properties of manganese-doped mesoporous bioactive glass nanoparticles - Westhauser, Fabian; Wilkesmann, Sebastian; Nawaz, Qaisar; Schmitz, Sarah I.; Moghaddam, Arash; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2020)
Mesoporous bioactive glass nanoparticles (MBGNs) based on the SiO2–P2O5–CaO system have demonstrated promising properties for the local delivery of therapeutically active ions with the aim to improve their osteogenic properties. Manganese (Mn) has been identified as a candidate ion for local application in bone tissue engineering applications. It remains unknown how SiO2–P2O5–CaO-based MBGNs influence human bone marrow-derived mesenchymal stromal cells (BMSCs) in terms of viability, proliferation, and differentiation and how these features can be modified by the addition of Mn to the MBGNs' composition. Therefore, in this study, MBGNs (composition in mol%: 50 SiO2, 40 CaO, 10 P2O5) and its Mn-doped derivate 5Mn-MBGNs (composition in mol%: 50 SiO2, 35 CaO, 10 P2O5, 5 MnO) were applied to a culture of BMSCs in two different concentrations. With increasing concentration, 5Mn-MBGNs supported osteogenic differentiation and enhanced the upregulation of genes encoding for extracellular matrix proteins but also negatively influenced cell viability and proliferation. When applied in lower concentrations, MBGNs showed not only viability- and growth-enhancing effects but also significant pro-osteogenic features—however, these positive properties deteriorated with increasing concentration. Two major conclusions can be drawn from this study: (a) supplementation with Mn enhances the osteogenic properties of MBGNs in a dose-dependent manner and (b) MBGNs constitute an attractive vector for therapeutically active ions since it exhibits an intrinsic pro-osteogenic potential that can be improved and/or modified by incorporation of therapeutically active ions. Future studies should focus on the evaluation of further candidate ions that are known to influence osteogenic differentiation positively.
CRIS-Team Scopus Importer:2020-05-02
Keywords: bone tissue engineering; human mesenchymal stromal cells; manganese; mesoporous bioactive glass nanoparticles; osteogenic differentiation

Oxidation and thermal degradation resistance of silicon carbide coated low density carbon-carbon composite - Ahmed, A. S.; Rawlings, R. D.; Ellacott, S. D.; Boccaccini, Aldo R. (Advances in Applied Ceramics, 2013)
The material investigated in this study is a prototype material, where a low density and highly porous carbon-carbon composite, termed carbon bonded carbon fibre (CBCF), has been given a protective coating of silicon carbide using chemical vapour deposition. The aim of the current study was to gauge the effectiveness of the silicon carbide coating in protecting the CBCF materials from degradation within an oxidising atmosphere. Avenues of investigation included assessing the behaviour of the materials when heated to elevated temperatures within an oxidising environment (using thermogravimetric analysis and bulk oxidation tests) and also evaluating the residual strength of the composites after subjection to thermal shock/cycling. It has been found that the performance of the CBCF material in oxidising conditions has improved with the incorporation of the silicon carbide coating and also that the coated material is resilient against thermal shock/cycling. © 2013 Institute of Materials.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.oxidat
Keywords: Carbon-carbon composites; Chemical vapour deposition; Oxidation protection; Silicon carbide; Thermal shock

Oxidized Alginate-Based Hydrogels for Tissue Engineering Applications: A Review - Reakasame, Supachai; Boccaccini, Aldo R. (Biomacromolecules, 2018)

Oxidized alginate-gelatin (ADA-GEL)/silk fibroin/Cu-Ag doped mesoporous bioactive glass nanoparticle-based hydrogels for potential wound care treatments - Akhtar, Memoona; Nazneen, Arooba; Awais, Muhammad; Hussain, Rabia; Khan, Ahmad; Irfan, Muhammad; Avcu, Egemen; Ur Rehman, Muhammad Atiq; Boccaccini, Aldo R. (Biomedical Materials, 2024)
The present work focuses on developing 5% w/v oxidized alginate (alginate di aldehyde, ADA)-7.5% w/v gelatin (GEL) hydrogels incorporating 0.25% w/v silk fibroin (SF) and loaded with 0.3% w/v Cu-Ag doped mesoporous bioactive glass nanoparticles (Cu-Ag MBGNs). The microstructural, mechanical, and biological properties of the composite hydrogels were characterized in detail. The porous microstructure of the developed ADA-GEL based hydrogels was confirmed by scanning electron microscopy, while the presence of Cu-Ag MBGNs in the synthesized hydrogels was determined using energy dispersive x-ray spectroscopy. The incorporation of 0.3% w/v Cu-Ag MBGNs reduced the mechanical properties of the synthesized hydrogels, as investigated using micro-tensile testing. The synthesized ADA-GEL loaded with 0.25% w/v SF and 0.3% w/v Cu-Ag MBGNs showed a potent antibacterial effect against Escherichia coli and Staphylococcus aureus. Cellular studies using the NIH3T3-E1 fibroblast cell line confirmed that ADA-GEL films incorporated with 0.3% w/v Cu-Ag MBGNs exhibited promising cellular viability as compared to pure ADA-GEL (determined by WST-8 assay). The addition of SF improved the biocompatibility, degradation rate, moisturizing effects, and stretchability of the developed hydrogels, as determined in vitro. Such multimaterial hydrogels can stimulate angiogenesis and exhibit desirable antibacterial properties. Therefore further (in vivo) tests are justified to assess the hydrogels’ potential for wound dressing and skin tissue healing applications.
CRIS-Team Scopus Importer:2024-03-29
Keywords: alginate; antibacterial activity; biocompatibility; gelation; silk; wound healing

Oxidized Alginate-Gelatin Hydrogel: A Favorable Matrix for Growth and Osteogenic Differentiation of Adipose-Derived Stem Cells in 3D - Sarker, Bapi; Zehnder, Tobias; Rath, Subha N.; Horch, Raymund E.; Kneser, Ulrich; Detsch, Rainer; Boccaccini, Aldo R. (ACS Biomaterials Science and Engineering, 2017)
Keywords: 3D; alginate; hydrogel; microbead; osteogenic differentiation; stem cell

Oxidized alginate hydrogels with the GHK peptide enhance cord blood mesenchymal stem cell osteogenesis: A paradigm for metabolomics-based evaluation of biomaterial design - Klontzas, Michail E.; Reakasame, Supachai; Silva, Raquel; Morais, Jose C. F.; Vernardis, Spyros; Macfarlane, Robert J.; Heliotis, Manolis; Tsiridis, Eleftherios; Panoskaltsis, Nicki; Boccaccini, Aldo R.; Mantalaris, Athanasios (Acta Biomaterialia, 2019)
Oxidized alginate hydrogels are appealing alternatives to natural alginate due to their favourable biodegradability profiles and capacity to self-crosslink with amine containing molecules facilitating functionalization with extracellular matrix cues, which enable modulation of stem cell fate, achieve highly viable 3-D cultures, and promote cell growth. Stem cell metabolism is at the core of cellular fate (proliferation, differentiation, death) and metabolomics provides global metabolic signatures representative of cellular status, being able to accurately identify the quality of stem cell differentiation. Herein, umbilical cord blood mesenchymal stem cells (UCB MSCs) were encapsulated in novel oxidized alginate hydrogels functionalized with the glycine-histidine-lysine (GHK) peptide and differentiated towards the osteoblastic lineage. The ADA-GHK hydrogels significantly improved osteogenic differentiation compared to gelatin-containing control hydrogels, as demonstrated by gene expression, alkaline phosphatase activity and bone extracellular matrix deposition. Metabolomics revealed the high degree of metabolic heterogeneity in the gelatin-containing control hydrogels, captured the enhanced osteogenic differentiation in the ADA-GHK hydrogels, confirmed the similar metabolism between differentiated cells and primary osteoblasts, and elucidated the metabolic mechanism responsible for the function of GHK. Our results suggest a novel paradigm for metabolomics-guided biomaterial design and robust stem cell bioprocessing.
CRIS-Team WoS Importer:2019-04-18

Oxidized Hyaluronic Acid-Gelatin-Based Hydrogels for Tissue Engineering and Soft Tissue Mimicking - Kuth, Sonja; Karakaya, Emine; Reiter, Nina; Schmidt, Lorenz-Peter; Paulsen, Friedrich; Tessmar, Jorg; Budday, Silvia; Boccaccini, Aldo R. (Tissue Engineering - Part C: Methods, 2022)
Hydrogels are ideal materials for mimicking and engineering soft tissue. Hyaluronic acid is a linear polysaccharide native to the human extracellular matrix. In this study, we first develop and characterize two hydrogel compositions built from oxidized HA and gelatin with and without alginate-di-aldehyde (ADA) crosslinked by ionic and enzymatic agents with potential applications in soft tissue engineering and tissue mimicking structures. The stability under incubation conditions was improved by adjusting crosslinking times. Through large-strain mechanical measurements, the hydrogels' properties were compared to human brain tissue and the samples containing ADA revealed similar mechanical properties to the native tissue specimens in cyclic compression-tension. In vitro characterization demonstrated a high viability of encapsulated mouse embryonic fibroblasts and a spreading of the cells in case of ADA-free samples.
CRIS-Team WoS Importer:2022-05-20

Oxygen-Deficient Bioceramics: Combination of Diagnosis, Therapy, and Regeneration - Bigham, Ashkan; Raucci, Maria Grazia; Zheng, Kai; Boccaccini, Aldo R.; Ambrosio, Luigi (Advanced Materials, 2023)
The journey of ceramics in medicine has been synchronized with an evolution from the first generation—alumina, zirconia, etc.—to the third —3D scaffolds. There is an up-and-coming member called oxygen-deficient or colored bioceramics, which have recently found their way through biomedical applications. The oxygen vacancy steers the light absorption toward visible and near infrared regions, making the colored bioceramics multifunctional—therapeutic, diagnostic, and regenerative. Oxygen-deficient bioceramics are capable of turning light into heat and reactive oxygen species for photothermal and photodynamic therapies, respectively, and concomitantly yield infrared and photoacoustic images. Different types of oxygen-deficient bioceramics have been recently developed through various synthesis routes. Some of them like TiO2−x, MoO3−x, and WOx have been more investigated for biomedical applications, whereas the rest have yet to be scrutinized. The most prominent advantage of these bioceramics over the other biomaterials is their multifunctionality endowed with a change in the microstructure. There are some challenges ahead of this category discussed at the end of the present review. By shedding light on this recently born bioceramics subcategory, it is believed that the field will undergo a big step further as these platforms are naturally multifunctional.
CRIS-Team Scopus Importer:2023-08-11
Keywords: biomedical applications; cancer diagnosis and therapy; oxygen-deficient bioceramics; regenerative medicine; tissue engineering

Oxygen diffusion in marine-derived tissue engineering scaffolds - Boccardi, Elena; Belova, I. V.; Murch, G. E.; Boccaccini, Aldo R.; Fiedler, T. (Journal of Materials Science: Materials in Medicine, 2015)
This paper addresses the computation of the effective diffusivity in new bioactive glass (BG) based tissue engineering scaffolds. High diffusivities facilitate the supply of oxygen and nutrients to grown tissue as well as the rapid disposal of toxic waste products. The present study addresses required novel types of bone tissue engineering BG scaffolds that are derived from natural marine sponges. Using the foam replication method, the scaffold geometry is defined by the porous structure of Spongia Agaricina and Spongia Lamella. These sponges present the advantage of attaining scaffolds with higher mechanical properties (2–4 MPa) due to a decrease in porosity (68–76 %). The effective diffusivities of these structures are compared with that of conventional scaffolds based on polyurethane (PU) foam templates, characterised by high porosity (>90 %) and lower mechanical properties (>0.05 MPa). Both the spatial and directional variations of diffusivity are investigated. Furthermore, the effect of scaffold decomposition due to immersion in simulated body fluid (SBF) on the diffusivity is addressed. Scaffolds based on natural marine sponges are characterised by lower oxygen diffusivity due to their lower porosity compared with the PU replica foams, which should enable the best oxygen supply to newly formed bone according the numerical results. The oxygen diffusivity of these new BG scaffolds increases over time as a consequence of the degradation in SBF.

PDLLA scaffolds with Cu- and Zn-doped bioactive glasses having multifunctional properties for bone regeneration - Bejarano, Julian; Detsch, Rainer; Boccaccini, Aldo R.; Palza, Humberto (Journal of Biomedical Materials Research Part A, 2017)
Keywords: bioactive glasses; biodegradable polymer scaffolds; bone regeneration; copper and zinc ions; multifunctional properties

PEEK Based Biocompatible Coatings Incorporating h-BN and Bioactive Glass by Electrophoretic Deposition - Virk, Ranjot; Ur Rehman, Muhammad Atiq; Boccaccini, Aldo R. (ECS Transactions, 2018)
In this study, we deposit composite coatings based on polyether ether ketone (PEEK), bioactive glass (BG) and hexagonal boron nitride (h-BN) particles via electrophoretic deposition (EPD) on stainless steel (SS316-L). The compounds have been characterized in terms of morphology, composition, adhesion strength, and compatibility in vitro bioactivity. Scanning electron microscopy (SEM) showed the uniform dispersion of PEEK, BG and h-BN particles in the deposit. The coatings were sintered in a furnace at 375 ° C for 30 minutes. SEM analysis showed that PEEK is a uniform matrix embedded with BG and h-BN particles. Energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy (FTIR) confirmed the presence of PEEK, BG and h-BN.The sintered coating shows appropriate adhesion to the substrate (qualitatively assessed). Moreover, the hydrophilicity for initial protein attachment. Finally, the coatings formed in a simulated body fluid, as confirmed by SEM and FTIR analysis.

Perfusable Tissue Bioprinted into a 3D-Printed Tailored Bioreactor System - Gensler, Marius; Malkmus, Christoph; Ockermann, Philipp; Möllmann, Marc; Hahn, Lukas; Salehi, Sahar; Luxenhofer, Robert; Boccaccini, Aldo R.; Hansmann, Jan (Bioengineering, 2024)
Bioprinting provides a powerful tool for regenerative medicine, as it allows tissue construction with a patient’s specific geometry. However, tissue culture and maturation, commonly supported by dynamic bioreactors, are needed. We designed a workflow that creates an implant-specific bioreactor system, which is easily producible and customizable and supports cell cultivation and tissue maturation. First, a bioreactor was designed and different tissue geometries were simulated regarding shear stress and nutrient distribution to match cell culture requirements. These tissues were then directly bioprinted into the 3D-printed bioreactor. To prove the ability of cell maintenance, C2C12 cells in two bioinks were printed into the system and successfully cultured for two weeks. Next, human mesenchymal stem cells (hMSCs) were successfully differentiated toward an adipocyte lineage. As the last step of the presented strategy, we developed a prototype of an automated mobile docking station for the bioreactor. Overall, we present an open-source bioreactor system that is adaptable to a wound-specific geometry and allows cell culture and differentiation. This interdisciplinary roadmap is intended to close the gap between the lab and clinic and to integrate novel 3D-printing technologies for regenerative medicine.
CRIS-Team Scopus Importer:2024-02-02
Keywords: 3D-printing; adipose tissue; biofabrication; bioprinting; cell culture simulation; perfusable bioreactor

Permeability evaluation of 45S5 Bioglass (R)-based scaffolds for bone tissue engineering - Ochoa, Ignacio; Sanz-Herrera, Jose A.; Garcia-Aznar, Jose M.; Doblare, Manuel; Yunos, Darmawati Mohamad; Boccaccini, Aldo R. (Journal of Biomechanics, 2009)
Permeability is a key parameter for microstructural design of scaffolds, since it is related to their capability for waste removal and nutrients/oxygen supply. In this framework, Darcy's experiments were carried out in order to determine the relationship between the pressure drop gradient and the fluid flow velocity in Bioglass®-based scaffolds to obtain the scaffold's permeability. Using deionised water as working fluid, the measured average permeability value on scaffolds of 90-95% porosity was 1.96×10-9 m2. This value lies in the published range of permeability values for trabecular bone. © 2008 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.permea
Keywords: Bioglass; Darcy's equation; Permeability; Tissue engineering

Phase-specific bioactivity and altered Ostwald ripening pathways of calcium carbonate polymorphs in simulated body fluid - Myszka, Barbara; Schüßler, Martina; Hurle, Katrin; Demmert, Benedikt; Detsch, Rainer; Boccaccini, Aldo R.; Wolf, Stephan (RSC Advances, 2019)
Calcium carbonate is an abundant biomineral, and already archeological records demonstrate its bioactivity and applicability for osseo-integrative implants. Its solubility, which is generally higher than those of calcium phosphates, depends on its polymorph turning calcium carbonate into a promising biomaterial with tunable bioresorption rate. However, the phase-dependent bioactivity of calcium carbonate, i.e., its osteoconductivity, is still insufficiently characterized. In this study, we address this issue by monitoring the behavior of the four most important calcium carbonate phases, i.e., calcite, aragonite, vaterite, and amorphous calcium carbonate, in simulated body fluid solution at 37 °C. Our results demonstrate that the thermodynamically stable calcite phase is essentially inert. In contrast, the metastable phases aragonite and vaterite are bioactive, thus promoting the formation of calcium phosphate. Amorphous calcium carbonate (ACC) shows prominent bioactivity accompanied by pronounced redissolution processes. Mg-stabilized ACC was additionally tested since its increased stability eases formulation and handling in future applications. It is highly bioactive and, moreover, the additional release of Mg promotes cell viability. Overall, our results demonstrate that bioactivity of calcium carbonate is phase-dependent, allowing tailored response and bioactivity of future calcareous biomaterials. Our results also reveal that phosphate ions strongly interfere with Ostwald-Lussac step ripening of calcium carbonate, kinetically stabilizing metastable polymorphs such as vaterite and aragonite; this is a distinctive feature of the calcium carbonate mineral system which clearly has to be considered in future applications of calcium carbonate as a bioceramic.
CRIS-Team Scopus Importer:2019-07-09

Phosphate glass fibers facilitate proliferation and osteogenesis through Runx2 transcription in murine osteoblastic cells - Lin, Xiao; Chen, Qiang; Xiao, Yunyun; Gao, Yongguang; Ahmed, Ifty; Li, Meng; Li, Hui; Zhang, Kewen; Qiu, Wuxia; Liu, Xianhu; Boccaccini, Aldo R.; Qian, Airong (Journal of Biomedical Materials Research Part A, 2019)
Cell-material interactions and compatibility are important aspects of bioactive materials for bone tissue engineering. Phosphate glass fiber (PGF) is an attractive inorganic filler with fibrous structure and tunable composition, which has been widely investigated as a bioactive filler for bone repair applications. However, the interaction of osteoblasts with PGFs has not been widely investigated to elucidate the osteogenic mechanism of PGFs. In this study, different concentrations of short PGFs with interlaced oriented topography were cocultured with MC3T3-E1 cells for different periods, and the synergistic effects of fiber topography and ionic product of PGFs on osteoblast responses including cell adhesion, spreading, proliferation, and osteogenic differentiation were investigated. It was found that osteoblasts were more prone to adhere on PGFs through Vinculin protein, leading to enhanced cell proliferation with polygonal cell shape and spreading cellular actin filaments. In addition, osteoblasts incubated on PGF meshes showed enhanced alkaline phosphatase activity, extracellular matrix mineralization, and increased expression of osteogenesis-related marker genes, which could be attributed to the Wnt/beta-catenin/Runx2 signaling pathway. This study elucidated the possible mechanism of PGF on triggering specific osteoblast behavior, which would be highly beneficial for designing PGF-based bone graft substitutes with excellent osteogenic functions.
CRIS-Team WoS Importer:2019-11-15

Phosphate glass fibres with therapeutic ions release capability–a review - Lapa, Agata; Cresswell, Mark; Jackson, Phil; Boccaccini, Aldo R. (Advances in Applied Ceramics, 2020)
Phosphate-based glasses (PBG) have low melting temperatures and can be obtained by melt-quenching and sol-gel methods. The most significant characteristic of PBG is their ability to dissolve completely in aqueous solution within different timeframes. This solubility can reduce the need for revision surgeries and makes PBG well-suited for soft tissue regeneration. Phosphate glass fibres (PGF) due to their geometry and volume–surface area ratio are the subject of a growing number of studies on resorbable composites. Medical applications include bone fixation devices, nerve tissue scaffolds and wound healing. PBG can be doped with various ions to enhance their biological, chemical and structural properties allowing the preparation of fibres with designed properties and with the ability to release biologically active ions upon degradation. The aim of this review is to look in detail at the influence of different dopants on PGF behaviour, both at a structural and biological level.
CRIS-Team Scopus Importer:2019-12-24
Keywords: bone; bone fixation devices; hard tissue regeneration; metal ions; Phosphate glass fibres; soft tissue regeneration; soluble glasses; therapeutic ions

Photo-cross-linkable hyaluronic acid bioinks for bone and cartilage tissue engineering applications - Ghorbani, Farnaz; Ghalandari, Behafarid; Khajehmohammadi, Mehran; Bakhtiary, Negar; Tolabi, Hamidreza; Sahranavard, Melika; Fathi-Karkan, Sonia; Nazar, Vida; Hasan Niari Niar, Shalaleh; Armoon, Amirhosein; Ettelaei, Maryam; Tavakoli Banizi, Milad; et al. (International Materials Reviews, 2023)
Hyaluronic acid (HA) is of immense importance to biomaterials science and biomedical engineering. It is finding applications in diverse areas of bioengineering ranging from scaffolds for disease modelling to tissue culture for reconstruction. This review focuses on recent research on the role of HA as a photo-cross-linked bioink and its importance in combating bone and cartilage-related disease, injury and disorders. Photo chemical modifications and 3D fabrication technologies employed to produce HA-modified materials are analysed to provide a fundamental understanding of the structure–function-property relationships that influence printability, shape fidelity and biological performance both in-vitro and in-vivo. The article concludes with a future vision for HA-based bioinks and their deployment in light-based bioprinting technologies for bone and cartilage repair.
CRIS-Team Scopus Importer:2023-02-10
Keywords: 3D-print; bioink; bioprint; bone; cartilage; Hyaluronic acid; photo-cross-linkable; tissue engineering

pH-Triggered Controlled Release of Chlorhexidine Using Chitosan-Coated Titanium Silica Composite for Dental Infection Prevention - Srivastava, Mrinal Gaurav; Kamarudin, Nur Hidayatul Nazirah; Aktan, Merve Kübra; Zheng, Kai; Zayed, Naiera; Yongabi, Derick; Wagner, Patrick; Teughels, Wim; Boccaccini, Aldo R.; Braem, Annabel (Pharmaceutics, 2024)
Peri-implantitis is a growing pathological concern for dental implants which aggravates the occurrence of revision surgeries. This increases the burden on both hospitals and the patients themselves. Research is now focused on the development of materials and accompanying implants designed to resist biofilm formation. To enhance this endeavor, a smart method of biofilm inhibition coupled with limiting toxicity to the host cells is crucial. Therefore, this research aims to establish a proof-of-concept for the pH-triggered release of chlorhexidine (CHX), an antiseptic commonly used in mouth rinses, from a titanium (Ti) substrate to inhibit biofilm formation on its surface. To this end, a macroporous Ti matrix is filled with mesoporous silica (together referred to as Ti/SiO2), which acts as a diffusion barrier for CHX from the CHX feed side to the release side. To limit release to acidic conditions, the release side of Ti/SiO2 is coated with crosslinked chitosan (CS), a pH-responsive and antimicrobial natural polymer. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX) and Fourier transform infrared (FTIR) spectroscopy confirmed successful CS film formation and crosslinking on the Ti/SiO2 disks. The presence of the CS coating reduced CHX release by 33% as compared to non-coated Ti/SiO2 disks, thus reducing the antiseptic exposure to the environment in normal conditions. Simultaneous differential scanning calorimetry and thermogravimetric analyzer (SDT) results highlighted the thermal stability of the crosslinked CS films. Quartz crystal microbalance with dissipation monitoring (QCM-D) indicated a clear pH response for crosslinked CS coatings in an acidic medium. This pH response also influenced CHX release through a Ti/SiO2/CS disk where the CHX release was higher than the average trend in the neutral medium. Finally, the antimicrobial study revealed a significant reduction in biofilm formation for the CS-coated samples compared to the control sample using viability quantitative polymerase chain reaction (v-qPCR) measurements, which were also corroborated using SEM imaging. Overall, this study investigates the smart triggered release of pharmaceutical agents aimed at inhibiting biofilm formation, with potential applicability to implant-like structures.
CRIS-Team Scopus Importer:2024-04-05
Keywords: biofilm inhibition; chitosan; chlorhexidine; controlled drug release; dental implant; mesoporous silica; pH response; titanium

Physical and Antibacterial Properties of Peppermint Essential Oil Loaded Poly (epsilon-caprolactone) (PCL) Electrospun Fiber Mats for Wound Healing - Ünalan, Irem; Slavik, Benedikt; Büttner, Andrea; Goldmann, Wolfgang; Frank, Gerhard; Boccaccini, Aldo R. (Frontiers in Bioengineering and Biotechnology, 2019)
The aim of this study was to fabricate and characterize various concentrations of peppermint essential oil (PEP) loaded on poly(epsilon-caprolactone) (PCL) electrospun fiber mats for healing applications, where PEP was intended to impart antibacterial activity to the fibers. SEM images illustrated that the morphology of all electrospun fiber mats was smooth, uniform, and bead-free. The average fiber diameter was reduced by the addition of PEP from 1.6 +/- 0.1 to 1.0 +/- 0.2 mu m. Functional groups of the fibers were determined by Raman spectroscopy. Gas chromatography-mass spectroscopy (GC-MS) analysis demonstrated the actual PEP content in the samples. In vitro degradation was determined by measuring weight loss and their morphology change, showing that the electrospun fibers slightly degraded by the addition of PEP. The wettability of PCL and PEP loaded electrospun fiber mats was measured by determining contact angle and it was shown that wettability increased with the incorporation of PEP. The antimicrobial activity results revealed that PEP loaded PCL electrospun fiber mats exhibited inhibition against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria. In addition, an in-vitro cell viability assay using normal human dermal fibroblast (NHDF) cells revealed improved cell viability on PCL, PCLPEP1.5, PCLPEP3, and PCLGEL6 electrospun fiber mats compared to the control (CNT) after 48 h cell culture. Our findings showed for the first time PEP loaded PCL electrospun fiber mats with antibiotic-free antibacterial activity as promising candidates for wound healing applications.
CRIS-Team WoS Importer:2019-12-27
Keywords: wound healing; peppermint essential oil; poly (ε-caprolactone); electrospinning; antibacterial activity

Physical characterizations and biological properties of PHP/PCL electrospun fibermats - Ding, Yaping; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (European Polymer Federation, 2015)

Physicochemical, biological and drug-release properties of gallium crosslinked alginate/nanoparticulate bioactive glass composite films - Mourino, V.; Newby, P.; Pishbin, F.; Cattalini, J. P.; Lucangioli, S.; Boccaccini, Aldo R. (Soft Matter, 2011)
The aim of this work was to develop biodegradable and bioactive materials with sufficient structural integrity and prophylaxis effect against infection based on alginate-bioactive glass composite. The incorporation of bioactive glass nanoparticles (NBG) into Ga-crosslinked alginate films significantly improved their mechanical properties when compared with films fabricated with micron-sized bioactive glass particles. In addition, Ga-alginate films containing NBG induced a bacteriostatic effect in vitro towards S. aureus due to the presence of Ga ions (Ga 3+), whose release is controlled solely by crosslinking the ion with alginate. Biomineralization studies in simulated body fluid suggested the deposition of hydroxyapatite on the surface of the films indicating their bioactive nature. In addition, the films were shown to feature biocompatibility toward osteoblast-like cells. Thus, it was shown that Ga-crosslinked composite films possessed relevant physicochemical, biological and controlled bacteriostatic effects which make these materials promising candidates for bone tissue engineering applications. © 2011 The Royal Society of Chemistry.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.physic

Physico-chemical modification of gelatine for the improvement of 3D printability of oxidized alginate-gelatine hydrogels towards cartilage tissue engineering - Kreller, Thomas; Distler, Thomas; Heid, Susanne; Gerth, S.; Detsch, Rainer; Boccaccini, Aldo R. (Materials & Design, 2021)
This work explored 3D printing to mimic the intrinsic hierarchical structure of natural articular cartilage. Alginate di-aldehyde- gelatine (ADA-GEL) hydrogel was used as ink to create hierarchically ordered scaffolds. In comparison to previously reported ADA-GEL compositions, we introduce a modified formulation featuring increased amounts of thermally modified gelatine. Gelatine was degraded by hydrolysis which resulted in tailorable printability characteristics further substantiated by rheological analysis. ADA (3.75 %w/v)-GEL (7.5 %w/v) with gelatine modified at 80 °C for 3 h could be printed in hierarchical complex structures reaching scaffold heights of over 1 cm. The hierarchical structure of the scaffolds was confirmed via µCT analysis. To examine mechanical properties as well as the suitability of the hydrogel as a proper matrix for cell seeding and encapsulation, nanoindentation was performed. Elastic moduli in the range of 5 kPa were measured. Gelatine heat pre-treatment resulted in modifiable mechanical and rheological characteristics of ADA-GEL. In summary, this study demonstrates the possibility to enhance the printability of ADA-GEL hydrogels to fabricate hierarchical scaffold structures with shape stability and fidelity, without the necessity to change the initial hydrogel chemistry by the use of additives or crosslinkers, providing a valuable approach for fabrication of designed scaffolds for cartilage tissue engineering.
CRIS-Team Scopus Importer:2021-07-16
Keywords: 3D Printing; Gelatine; Hydrogels; Oxidized Alginate; Tissue Engineering

Phytotherapeutic Hierarchical PCL-Based Scaffolds as a Multifunctional Wound Dressing: Combining 3D Printing and Electrospinning - Ünalan, Irem; Slavik, Benedikt; Büttner, Andrea; Boccaccini, Aldo R. (Macromolecular Bioscience, 2024)
This study focuses on developing hybrid scaffolds incorporating phytotherapeutic agents via a combination of three-dimensional (3D) printing and electrospinning to enhance mechanical properties and provide antibacterial activity, in order to address the limitations of traditional antibiotics. In this regard, 3D-printed polycaprolactone (PCL) struts are first fabricated using fused deposition modeling (FDM). Then, alkaline surface treatment is applied to improve the adhesion of electrospun nanofibers. Finally, peppermint oil (PEP) or clove oil (CLV)-incorporated PCL-gelatin (GEL) electrospun nanofibers are collected on top of the 3D-printed PCL scaffolds by electrospinning. Incorporating PEP or CLV into PCL-GEL electrospun nanofibers enhances the scaffold's layer detachment and adhesion force. In addition, the DPPH free radical scavenging activity assay indicates that incorporating PEP or CLV improves the antioxidant properties of the scaffolds. Further, antibacterial activity results reveal that PEP or CLV incorporated scaffolds exhibit inhibition against Staphylococcus aureus and Escherichia coli bacteria. Moreover, anti-inflammatory assays show that scaffolds reduce the concentration of nitric oxide (NO) released from Raw 264.7 macrophage-like cells. On the other hand, the phytotherapeutic hierarchical scaffolds have no toxic effect on normal human dermal fibroblast (NHDF) cells, and PEP or CLV enhance cell attachment and proliferation. Overall, incorporating natural phytotherapeutic agents into hierarchical scaffolds shows promise for advancing wound healing applications.
CRIS-Team Scopus Importer:2024-09-20
Keywords: 3D printing; electrospinning; essential oils; hierarchical scaffolds; wound healing

Plasticity of 3D Hydrogels Predicts Cell Biological Behavior - Malandrino, Andrea; Zhang, Huijun; Schwarm, Nico; Böhringer, David; Kah, Delf-Thorge Eric; Kuster, Christian; Boccaccini, Aldo R.; Fabry, Ben (Biomacromolecules, 2024)
Under 3D culture conditions, cells tend to spread, migrate, and proliferate better in more viscoelastic and plastic hydrogels. Here, we present evidence that the improved cell behavior is facilitated by the lower steric hindrance of a more viscoelastic and plastic matrix with weaker intermolecular bonds. To determine intermolecular bond stability, we slowly insert semispherical tipped needles (100-700 μm diameter) into alginate dialdehyde-gelatin hydrogels and measure stiffness, yield strength, plasticity, and the force at which the surface ruptures (puncture force). To tune these material properties without affecting matrix stiffness, we precross-link the hydrogels with CaCl2 droplets prior to mixing in NIH/3T3 fibroblasts and final cross-linking with CaCl2. Precross-linking introduces microscopic weak spots in the hydrogel, increases plasticity, and decreases puncture force and yield strength. Fibroblasts spread and migrate better in precross-linked hydrogels, demonstrating that intermolecular bond stability is a critical determinant of cell behavior under 3D culture conditions.
CRIS-Team Scopus Importer:2025-02-04

Plug-and-Play Multimaterial Chaotic Printing/Bioprinting to Produce Radial and Axial Micropatterns in Hydrogel Filaments - Ceballos-González, Carlos Fernando; Bolívar-Monsalve, Edna Johana; Quevedo-Moreno, Diego Alonso; Chávez-Madero, Carolina; Velásquez-Marín, Silvana; Lam-Aguilar, Li Lu; Solís-Pérez, Óscar Emmanuel; Cantoral-Sánchez, Ariel; Neher, Mara; Yzar-García, Estefanía; Zhang, Yu Shrike; Gentile, Carmine; et al. (Advanced Materials Technologies, 2023)
Nature abounds with micro-architected materials containing layered multi-material patterns that often transition within the very same monolithic piece. Fabricating these complex materials using current technologies is challenging. Multimaterial chaotic printing is presented—an extrusive printing method based on the use of chaotic advection—that can fabricate microstructured hydrogels with well-defined multimaterial and multilayered micropatterns. Printheads containing internal Kenics static mixing (KSM) elements and top- and lateral-positioned inlets are used to produce a wide repertoire of multilayered hydrogel filaments. In this plug-and-play system, the radial and axial micropatterns can be designed ad hoc by defining the printhead configuration (i.e., the number of KSM elements and inlets, and the inlet positions) and the flow program (i.e., activation/deactivation of the ink-flow through each inlet). Computational fluid dynamics simulations closely predict the microstructure obtained by a given printhead configuration. The application of this platform is illustrated for easy fabrication of fibers with radial microgradients, bacterial ecosystems, structured emulsions, micro-channeled hydrogel filaments, a pre-vascularized tumor niche model, and skeletal muscle-like tissues with axial and radial transitions of bioactive glass compartments. It is envisioned that multimaterial chaotic printing will be a valuable addition to the toolbox of additive manufacturing for the rational fabrication of advanced materials.
CRIS-Team Scopus Importer:2023-09-29
Keywords: bioprinting; chaotic printing; micropatterns; multimaterials; radial and axial transitions

Poly(3-hydroxybutyrate) multifunctional composite scaffolds for tissue engineering applications - Misra, Superb K.; Ansari, Tahera I.; Valappil, Sabeel P.; Mohn, Dirk; Philip, Sheryl E.; Stark, Wendelin J.; Roy, Ipsita; Knowles, Jonathan C.; Salih, Vehid; Boccaccini, Aldo R. (Biomaterials, 2010)
Poly(3-hydroxybutyrate) (P(3HB)) foams exhibiting highly interconnected porosity (85% porosity) were prepared using a unique combination of solvent casting and particulate leaching techniques by employing commercially available sugar cubes as porogen. Bioactive glass (BG) particles of 45S5 Bioglass® grade were introduced in the scaffold microstructure, both in micrometer ((m-BG), <5 μm) and nanometer ((n-BG), 30 nm) sizes. The in vitro bioactivity of the P(3HB)/BG foams was confirmed within 10 days of immersion in simulated body fluid and the foams showed high level of protein adsorption. The foams interconnected porous microstructure proved to be suitable for MG-63 osteoblast cell attachment and proliferation. The foams implanted in rats as subcutaneous implants resulted in a non-toxic and foreign body response after one week of implantation. In addition to showing bioactivity and biocompatibility, the P(3HB)/BG composite foams also exhibited bactericidal properties, which was tested on the growth of Staphylococcus aureus. An attempt was made at developing multifunctional scaffolds by incorporating, in addition to BG, selected concentrations of Vitamin E or/and carbon nanotubes. P(3HB) scaffolds with multifunctionalities (viz. bactericidal, bioactive, electrically conductive, antioxidative behaviour) were thus produced, which paves the way for next generation of advanced scaffolds for bone tissue engineering. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.poly3h
Keywords: Bioactive glass; Bone tissue engineering; Carbon nanotubes; Composite materials; Poly(3-hydroxybutyrate); Scaffolds

Poly(3-hydroxyoctanoate), a promising new material for cardiac tissue engineering - Bagdadi, Andrea V.; Safari, Maryam; Dubey, Prachi; Basnett, Pooja; Sofokleous, Panagiotis; Humphrey, Eleanor; Locke, Ian; Edirisinghe, Mohan; Terracciano, Cesare; Boccaccini, Aldo R.; Knowles, Jonathan C.; Harding, Sian E.; et al. (Journal of Tissue Engineering and Regenerative Medicine, 2016)
Keywords: cardiac patches; cardiac tissue engineering; Poly(3-hydroxyoctanoate); polyhydroxyalkanoates

Poly-3-hydroxyoctanoate P(3HO), a Medium Chain Length Polyhydroxyalkanoate Homopolymer from Pseudomonas mendocina - Rai, Ranjana; Yunos, Darmawati M.; Boccaccini, Aldo R.; Knowles, Jonathan C.; Barker, Ian A.; Howdle, Steven M.; Tredwell, Gregory D.; Keshavarz, Tajalli; Roy, Ipsita (Biomacromolecules, 2011)
Pseudomonas mendocina was found to produce a unique homopolymer of poly(3-hydroxyoctanoate), P(3HO), rather than a copolymer, when grown on sodium octanoate as the sole carbon source. Although this polymer has been produced by other organisms, interestingly this is the first time an absolute homopolymer has been produced by a wild type organism. In addition, a detailed study on the effects of different extraction methods on the yield, molecular weight, thermal properties, and lipopolysaccharide content of P(3HO) has been carried out. The organism was able to accumulate P(3HO) up to 31.38% of its dry cell weight within 48 h in mineral salt medium. Characterization of the monomer was carried out using FTIR, GC-MS, 13C, 1H, and HSQC NMR spectroscopy. The polymer had a crystallinity of 37.5%, Young's modulus value of 11.6 MPa and contact angle of 77.3°. Microstructural studies of solvent cast polymer films revealed a smooth surface topography with a root-mean-square roughness value of 0.238 μm. © 2011 American Chemical Society.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.poly3h

Polyaniline based polymers in tissue engineering applications: a review - Rai, Ranjana; Roether, Judith; Boccaccini, Aldo R. (Progress in Biomedical Engineering, 2022)
A number of electrically conducting polymers, such as polyaniline (PANi), as well as functionalized aniline copolymers and composites, which are simultaneously biodegradable and conductive, have been applied for developing electrically conductive scaffolds for tissue engineering (TE) in recent years. The rationale behind these scaffolds is to induce ‘electroactivity’ in scaffolds, as many research works have shown that an intrinsic electrical activity leads to both increased regeneration rates and improved healing of damaged tissues. PANi is the conductive polymer of choice because it is economical and easy to process with a variety of methods. The resultant PANi based biomaterials have shown biocompatibility, conductivity, suitable processability, positive cellular response, as well as an intrinsic antibacterial effect in numerous research studies. The analysis of the literature has revealed that PANi based scaffolds have been investigated for TE applications including skin/wound healing, bone, cartilage, nerve/spinal cord, vascular, skeletal muscle repair and for the treatment of infertility. Although PANi based materials find widespread applications in other sectors, they are still far away from being commercially exploited as scaffolds for TE despite positive research results. This review aims to discuss and critically assess the current state of PANi based TE scaffolds for different applications. A future perspective for utilizing PANi based biomaterials for applications in TE is discussed, including recent considerations about potential cytotoxic effects.
CRIS-Team Scopus Importer:2022-11-25
Keywords: antibacterial; biocompatibility; conductivity; polyaniline; tissue engineering

Polycaprolactone Electrospun Fiber Mats Prepared Using Benign Solvents: Blending with Copper(II)-Chitosan Increases the Secretion of Vascular Endothelial Growth Factor in a Bone Marrow Stromal Cell Line - Gritsch, Lukas; Liverani, Liliana; Lovell, Christopher; Boccaccini, Aldo R. (Macromolecular Bioscience, 2020)
Inducing the formation of new blood vessels (angiogenesis) is an essential requirement for successful tissue engineering. Approaches have been proposed to enhance angiogenesis using growth factors and other biomolecules; however, this approaches present drawbacks in terms of high cost and patient safety. Copper is known to effectively regulate angiogenesis and can offer a more cost-effective alternative than the direct use of growth factors. With this study, a strategy to incorporate copper in electrospun fibrous scaffolds with pro-angiogenic properties is presented. Polycaprolactone (PCL) and copper(II)-chitosan are electrospun using benign solvents. The morphological and physicochemical properties of the fiber mats are investigated through scanning electron microscopy (SEM), static contact angle measurements, energy dispersive X-ray, and Fourier-transform infrared spectroscopies. Scaffold stability in phosphate buffered saline at 37 °C is monitored over 1 week. A bone marrow stromal cell line (ST-2) is cultured for 7 days and its behavior is evaluated using SEM, fluorescence microscopy and a tetrazolium salt-based colorimetric assay. Results confirm that PCL/copper(II)-chitosan is suitable for electrospinning. The fiber mats are biocompatible and favor cell colonization and infiltration. Most notably, the angiogenic potential of PCL/copper(II)-chitosan blends is confirmed by a three-fold increase in VEGF secretion by ST-2 cells in the presence of copper(II)-chitosan.
CRIS-Team Scopus Importer:2020-02-14
Keywords: angiogenesis; benign solvents; chitosan; copper; electrospinning; polycaprolactone

Poly-DL-lactic acid coated Bioglass® scaffolds: toughening effects and osteosarcoma cell proliferation - Bretcanu, Oana; Boccaccini, Aldo R.; Salih, Vehid (Journal of Materials Science, 2012)
The fabrication and in vitro characterisation of 45S5 Bioglass®-derived scaffolds coated with poly-DL-lactic acid (PDLLA) are presented. Two types of scaffolds with different porosities were studied. The scaffold microstructure was analysed by scanning electron microscopy before and after polymer coating. Compressive strength tests were performed in as-fabricated condition and after 28 days of immersion in simulated body fluid. It was found that PDLLA-coated samples have higher compression strength compared with the uncoated samples. Human osteosarcoma cell line (HOS-TE85) was used to determine the biocompatibility of the scaffolds. Cell proliferation and differentiated functions were investigated by AlamarBlue™, alkaline phosphatase and osteocalcin assays. The scaffolds were maintained in cell culture for periods of up to 14 days. The combined effects of the scaffold microstructure (porosity, surface roughness and bioreactivity) and the polymeric coating induce favourable HOS cell behaviour. The results confirmed the biocompatibility of Bioglass®/PDLLA composite scaffolds for HOS cell culture and contribute to the understanding of the characteristics of these scaffolds for potential applications in bone tissue engineering. © Springer Science+Business Media, LLC 2012.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.polydl

Polyetheretherketone (PEEK) coatings on stainless steel by electrophoretic deposition - Corni, Ilaria; Neumann, Nico; Eifler, Dietmar; Boccaccini, Aldo R. (Advanced Engineering Materials, 2008)
Electrophoretic deposition (EPD) of polyetheretherketone (PEEK) coatings on 316Lstainless steel plates has been demonstrated. Deposition time, suspension concentration, difference of potential and distance between electrodes are the main parameters influencing EPD. These parameters were varied in wide ranges and their influences on deposition was examined to optimize the EPD conditions. A PEEK powder and pure ethanol were employed for the suspension preparation. It was observed that with increasing PEEK concentration, the rate of deposition and the thickness of the deposit increased if all other parameters were kept constant. It was also observed that with increasing strength of electric field the thickness of the coating deposited from the same suspension increased and the deposition rate was higher due to higher electrophoretic mobility of the suspended particles. The microstructure and morphology of PEEK coatings were quite reproducible, thus EPD can be considered an effective approach to produce PEEK films on metallic substrates.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.polyet

Polyethylenimine Inclusion to Develop Aqueous Alginate-Based Core-Shell Capsules for Biomedical Applications - Vaziri, Asma Sadat; Alizadeh, Maryam; Vasheghani-Farahani, Ebrahim; Karakaya, Emine; Detsch, Rainer; Boccaccini, Aldo R. (ACS Applied Materials and Interfaces, 2024)
Aqueous core-shell structures can serve as an efficient approach that allows cells to generate 3D spheroids with in vivo-like cell-to-cell contacts. Here, a novel strategy for fabricating liquid-core-shell capsules is proposed by inverse gelation of alginate (ALG) and layer-by-layer (LbL) coating. We hypothesized that the unique properties of polyethylenimine (PEI) could be utilized to overcome the low structural stability and the limited cell recognition motifs of ALG. In the next step, alginate dialdehyde (ADA) enabled the Schiff-base reaction with free amine groups of PEI to reduce its possible toxic effects. Scanning electron microscopy and light microscopy images proved the formation of spherical hollow capsules with outer diameters of 3.0 ± 0.1 mm for ALG, 3.2 ± 0.1 mm for ALG/PEI, and 4.0 ± 0.2 mm for ALG/PEI/ADA capsules. The effective modulus increased by 3-fold and 5-fold when comparing ALG/PEI/ADA and ALG/PEI to ALG capsules, respectively. Moreover, PEI-coated capsules showed potential antibacterial properties against both Staphylococcus aureus and Escherichia coli, with an apparent inhibition zone. The cell viability results showed that all capsules were cytocompatible (above 75.5%). Cells could proliferate and form spheroids when encapsulated within the ALG/PEI/ADA capsules. Monitoring the spheroid thickness over 5 days of incubation indicated an increasing trend from 39.50 μm after 1 day to 66.86 μm after 5 days. The proposed encapsulation protocol represents a new in vitro platform for developing 3D cell cultivation and can be adapted to fulfill the requirements of various biomedical applications.
CRIS-Team Scopus Importer:2024-05-24
Keywords: core−shell; hollow capsules; polyethylenimine; sodium alginate; spheroids

Polyglycerol hyperbranched polyesters: Synthesis, properties and pharmaceutical and biomedical applications - Zamboulis, Alexandra; Nakiou, Eirini A.; Christodoulou, Evi; Bikiaris, Dimitrios N.; Kontonasaki, Eleana; Liverani, Liliana; Boccaccini, Aldo R. (International Journal of Molecular Sciences, 2019)
In a century when environmental pollution is a major issue, polymers issued from bio-based monomers have gained important interest, as they are expected to be environment-friendly, and biocompatible, with non-toxic degradation products. In parallel, hyperbranched polymers have emerged as an easily accessible alternative to dendrimers with numerous potential applications. Glycerol (Gly) is a natural, low-cost, trifunctional monomer, with a production expected to grow significantly, and thus an excellent candidate for the synthesis of hyperbranched polyesters for pharmaceutical and biomedical applications. In the present article, we review the synthesis, properties, and applications of glycerol polyesters of aliphatic dicarboxylic acids (from succinic to sebacic acids) as well as the copolymers of glycerol or hyperbranched polyglycerol with poly(lactic acid) and poly(ε-caprolactone). Emphasis was given to summarize the synthetic procedures (monomer molar ratio, used catalysts, temperatures, etc.,) and their effect on the molecular weight, solubility, and thermal and mechanical properties of the prepared hyperbranched polymers. Their applications in pharmaceutical technology as drug carries and in biomedical applications focusing on regenerative medicine are highlighted.
CRIS-Team Scopus Importer:2019-12-24
Keywords: Catalysts; Esterification reactions; Hyperbranched polymers; Medical and biomedical applications; Polycondensation; Polyglycerol polyesters

Poly(Glycerol Sebacate) Films Modified by Thermal Proteins for Cardiac Tissue Engineering - Tallawi, Marwa; Rai, Ranjana; Costa, Marina; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (Biomedical Engineering, 2013)
Scaffolds for cardiac tissue engineering must be designed to achieve adequate degradation kinetics and mechanical properties. In this study, bulk modification of poly(glycerol sebacate) (PGS) with different concentrations of thermal proteins (TP) was investigated to tailor the degradation properties of PGS. TP are poly-amino acids formed by heating a mixture of amino acids with minimal proportions of glutamic or aspartic acid. The degradation study of TP-PGS was performed in vitro in phosphate buffered saline (PBS) solution over a 21 day period. Results showed that the degradation rate of PGS increased with increasing content of TP. After 21 days in PBS, degradation weight loss values of 9.40% ± 0.07, 7.3% ± 0.8 and 6.0% ± 0.4 were determined for PGS-TP-2g, PGS-TP-0.01g and PGS-control, respectively. The studies also showed that TP altered the mechanical properties and surface hydrophilicity of PGS.
Keywords: Thermal proteins; degradation; poly(glycerol sebacate); cardiac tissue engineering

Poly(Glycerol Sebacate) in Biomedical Applications—A Review of the Recent Literature - Vogt, Lena; Ruther, Florian; Salehi, Sahar; Boccaccini, Aldo R. (Advanced Healthcare Materials, 2021)
Poly(glycerol sebacate) (PGS) continues to attract attention for biomedical applications owing to its favorable combination of properties. Conventionally polymerized by a two-step polycondensation of glycerol and sebacic acid, variations of synthesis parameters, reactant concentrations or by specific chemical modifications, PGS materials can be obtained exhibiting a wide range of physicochemical, mechanical, and morphological properties for a variety of applications. PGS has been extensively used in tissue engineering (TE) of cardiovascular, nerve, cartilage, bone and corneal tissues. Applications of PGS based materials in drug delivery systems and wound healing are also well documented. Research and development in the field of PGS continue to progress, involving mainly the synthesis of modified structures using copolymers, hybrid, and composite materials. Moreover, the production of self-healing and electroactive materials has been introduced recently. After almost 20 years of research on PGS, previous publications have outlined its synthesis, modification, properties, and biomedical applications, however, a review paper covering the most recent developments in the field is lacking. The present review thus covers comprehensively literature of the last five years on PGS-based biomaterials and devices focusing on advanced modifications of PGS for applications in medicine and highlighting notable advances of PGS based systems in TE and drug delivery.
CRIS-Team Scopus Importer:2021-03-26
Keywords: biodegradable polyester; bioelectronics; biomedical applications; composites; poly(glycerol sebacate); tissue engineering

Poly(Glycerol Sebacate)/Poly(Butylene Succinate-Butylene Dilinoleate) Fibrous Scaffolds for Cardiac Tissue Engineering - Tallawi, Marwa; Zebrowski, David; Rai, Ranjana; Roether, Judith; Schubert, Dirk W.; El Fray, Miroslawa; Engel, Felix; Aifantis, Katerina E.; Boccaccini, Aldo R. (Tissue Engineering - Part C: Methods, 2015)
The present article investigates the use of a novel electrospun fibrous blend of poly(glycerol sebacate) (PGS) and poly(butylene succinate-butylene dilinoleate) (PBS-DLA) as a candidate for cardiac tissue engineering. Random electrospun fibers with various PGS/PBS-DLA compositions (70/30, 60/40, 50/50, and 0/100) were fabricated. To examine the suitability of these fiber blends for heart patches, their morphology, as well as their physical, chemical, and mechanical properties were measured before examining their biocompatibility through cell adhesion. The fabricated fibers were bead-free and exhibited a relatively narrow diameter distribution. The addition of PBS-DLA to PGS resulted in an increase of the average fiber diameter, whereas increasing the amount of PBS-DLA decreased the hydrophilicity and the water uptake of the nanofibrous scaffolds to values that approached those of neat PBS-DLA nanofibers. Moreover, the addition of PBS-DLA significantly increased the elastic modulus. Initial toxicity studies with C2C12 myoblast cells up to 72 h confirmed nontoxic behavior of the blends. Immunofluorescence analyses and scanning electron microscopy analyses confirmed that C2C12 cells showed better cell attachment and proliferation on electrospun mats with higher PBS-DLA content. However, immunofluorescence analyses of the 3-day-old rat cardiomyocytes cultured for 2 and 5 days demonstrated better attachment on the 70/30 fibers containing well-aligned sarcomeres and expressing high amounts of connexin 43 in cellular junctions indicating efficient cell-to-cell communication. It can be concluded, therefore, that fibrous PGS/PBS-DLA scaffolds exhibit promising characteristics as a biomaterial for cardiac patch applications.

Poly(glycerol sebacate)(butylene succinate-dilinoleate) blends as candidate materials for cardiac tissue engineering - Boccaccini, Aldo R.; Aifantis, K.; Tallawi, Marwa; Rai, Ranjana; R-Gleixner, M.; Roerick, Olaf; Weyand, Michael; Roether, Judith; Schubert, Dirk W.; Kozlowska, A.; El Fray, Miroslawa; et al. (Macromolecular Symposia, 2013)
Poly (glycerol sebacate) (PGS) and poly (butylene succinate‐dilinoleate) (PBS‐DLA) are biodegradable polymers with potential application in cardiac tissue engineering. In the present study novel blends comprising PGS prepolymer and PBS‐DLA were prepared with varying compositions (70/30, 60/40, 50/50, 40/60, 30/70 and 0/100 in weight percentage). The physical, chemical, and mechanical properties of the PGS/PBS‐DLA blends were measured and compared. By adding PBS‐DLA to PGS the need for curing PGS prepolymer was eliminated, as the blended films are chemically stable. With increasing amount of PBS‐DLA the hydrophobicity of the blend system increased reaching values close to that of neat PBS‐DLA films. Furthermore, addition of PBS‐DLA significantly affected the mechanical properties of the blends, i.e. the elastic modulus of the blends was enhanced with increasing PBS‐DLA addition from 1.2 MPa to 54 MPa. At the same time, PBS‐DLA addition led to decreased degradation rate of the films. Furthermore the PBS‐DLA counteracted the acidity of the free carboxylic groups on the free end chains of the PGS prepolymer. In vitro cytocompatibility studies indicated high biocompatibility. Taken together the results confirm that the novel PGS/PBS‐DLA matrices exhibit promising characteristics as a biomaterial for application in cardiac regeneration approaches.
Keywords: myoblasts; poly (butylene succinate-dilinoleate); cardiac tissue engineering; mechanobiology; substrate stiffness

Poly(glycerol sebacate){Poly(butylene succinate-dilinoleate) Blends as Candidate Materials for Cardiac Tissue Engineering - Tallawi, Marwa; Rai, Ranjana; Ramsperger-Gleixner, Martina; Roerick, Olaf; Weyand, Michael; Roether, Judith; Schubert, Dirk W.; Kozlowska, A.; El Fray, Miroslawa; Aifantis, K.; Boccaccini, Aldo R.; et al. (WILEY-V C H VERLAG GMBH, 2013)
Poly (glycerol sebacate) (PGS) and poly (butylene succinate-dilinoleate) (PBS-DLA) are biodegradable polymers with potential application in cardiac tissue engineering. In the present study novel blends comprising PGS prepolymer and PBS-DLA were prepared with varying compositions (70/30, 60/40, 50/50, 40/60, 30/70 and 0/100 in weight percentage). The physical, chemical, and mechanical properties of the PGS/PBS-DLA blends were measured and compared. By adding PBS-DLA to PGS the need for curing PGS prepolymer was eliminated, as the blended films are chemically stable. With increasing amount of PBS-DLA the hydrophobicity of the blend system increased reaching values close to that of neat PBS-DLA films. Furthermore, addition of PBS-DLA significantly affected the mechanical properties of the blends, i.e. the elastic modulus of the blends was enhanced with increasing PBS-DLA addition from 1.2 MPa to 54 MPa. At the same time, PBS-DLA addition led to decreased degradation rate of the films. Furthermore the PBS-DLA counteracted the acidity of the free carboxylic groups on the free end chains of the PGS prepolymer. In vitro cytocompatibility studies indicated high biocompatibility. Taken together the results confirm that the novel PGS/PBS-DLA matrices exhibit promising characteristics as a biomaterial for application in cardiac regeneration approaches.
Keywords: cardiac tissue engineering; mechanobiology; myoblasts; poly (butylene succinate-dilinoleate); substrate stiffness

Poly(glycerol sebacate){Poly(butylene succinate-dilinoleate) Blends as Candidate Materials for Cardiac Tissue Engineering - Tallawi, Marwa; Rai, Ranjana; Ramsperger-Gleixner, Martina; Roerick, Olaf; Weyand, Michael; Roether, Judith; Schubert, Dirk W.; Kozlowska, A.; El Fray, M.; Aifantis, K.; Boccaccini, Aldo R.; et al. (Macromolecular Symposia, 2013)
Poly (glycerol sebacate) (PGS) and poly (butylene succinate-dilinoleate) (PBS-DLA) are biodegradable polymers with potential application in cardiac tissue engineering. In the present study novel blends comprising PGS prepolymer and PBS-DLA were prepared with varying compositions (70/30, 60/40, 50/50, 40/60, 30/70 and 0/100 in weight percentage). The physical, chemical, and mechanical properties of the PGS/PBS-DLA blends were measured and compared. By adding PBS-DLA to PGS the need for curing PGS prepolymer was eliminated, as the blended films are chemically stable. With increasing amount of PBS-DLA the hydrophobicity of the blend system increased reaching values close to that of neat PBS-DLA films. Furthermore, addition of PBS-DLA significantly affected the mechanical properties of the blends, i.e. the elastic modulus of the blends was enhanced with increasing PBS-DLA addition from 1.2 MPa to 54 MPa. At the same time, PBS-DLA addition led to decreased degradation rate of the films. Furthermore the PBS-DLA counteracted the acidity of the free carboxylic groups on the free end chains of the PGS prepolymer. In vitro cytocompatibility studies indicated high biocompatibility. Taken together the results confirm that the novel PGS/PBS-DLA matrices exhibit promising characteristics as a biomaterial for application in cardiac regeneration approache
Keywords: cardiac tissue engineering; mechanobiology; myoblasts; poly (butylene succinate-dilinoleate); substrate stiffness

Poly(Glycerol Succinate) as Coating Material for 1393 Bioactive Glass Porous Scaffolds for Tissue Engineering Applications - Nakiou, Eirini A.; Lazaridou, Maria; Pouroutzidou, Georgia K.; Michopoulou, Anna; Tsamesidis, Ioannis; Liverani, Liliana; Arango Ospina, Marcela; Beketova, Anastasia; Boccaccini, Aldo R.; Kontonasaki, Eleana; Bikiaris, Dimitrios N. (Polymers, 2022)
Background: Aliphatic polyesters are widely used for biomedical, pharmaceutical and environmental applications due to their high biodegradability and cost-effective production. Recently, star and hyperbranched polyesters based on glycerol and ω-carboxy fatty diacids have gained considerable interest. Succinic acid and bio-based diacids similar to glycerol are regarded as safe materials according to the US Food and Drug Administration (FDA). Bioactive glass scaffolds utilized in bone tissue engineering are relatively brittle materials. However, their mechanical properties can be improved by using polymer coatings that can further control their degradation rate, tailor their biocompatibility and enhance their performance. The purpose of this study is to explore a new biopolyester poly(glycerol succinate) (PGSuc) reinforced with mesoporous bioactive nanoparticles (MSNs) as a novel coating material to produce hybrid scaffolds for bone tissue engineering. Methods: Bioactive glass scaffolds were coated with neat PGSuc, PGSuc loaded with dexamethasone sodium phosphate (DexSP) and PGSuc loaded with DexSP-laden MSNs. The physicochemical, mechanical and biological properties of the scaffolds were also evaluated. Results: Preliminary data are provided showing that polymer coatings with and without MSNs improved the physicochemical properties of the 1393 bioactive glass scaffolds and increased the ALP activity and alizarin red staining, suggesting osteogenic differentiation potential when cultured with adipose-derived mesenchymal stem cells. Conclusions: PGSuc with incorporated MSNs coated onto 1393 bioactive glass scaffolds could be promising candidates in bone tissue engineering applications.
CRIS-Team Scopus Importer:2022-12-02
Keywords: 1393 bioactive glass scaffolds; bioactivity; dexamethasone; glycerol; mechanical properties; mesoporous nanoparticles; osteogenic differentiation; succinic acid

Poly(hydroxyalkanoate)s meet benign solvents for electrospinning - Brunetti, Lucia; Degli Esposti, Micaela; Morselli, Davide; Boccaccini, Aldo R.; Fabbri, Paola; Liverani, Liliana (Materials Letters, 2020)
Electrospinning (ES) technique allows the fabrication of nano/microfibers, relevant for tissue engineering (TE) applications. Several researches have been devoted to the use of benign solvents for ES, and in this work their use in combination with poly(hydroxyalkanoate)s (PHAs) is reported. Among PHAs, poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and their blend have been selected for their suitability for TE applications. The morphological and chemical properties of the electrospun mats, their degradation behaviour and cytocompatibility have been investigated, obtaining promising results and comparable properties with mats obtained using standard (not benign) solvents. Moreover, the fabrication of composite fibers incorporating bioactive glass (BG) particles is also reported as proof of concept.
CRIS-Team Scopus Importer:2020-08-14
Keywords: Benign solvents; Bioactive glass; Electrospinning; Poly(hydroxyalkanoate)s; Tissue engineering

Polylactide-based materials science strategies to improve tissue-material interface without the use of growth factors or other biological molecules. - Gritsch, Lukas; Conoscenti, Gioacchino; La Carrubba, Vincenzo; Nooeaid, Patcharakamon; Boccaccini, Aldo R. (Materials Science and Engineering C, 2019)
In a large number of medical devices, a key feature of a biomaterial is the ability to successfully bond to living tissues by means of engineered mechanisms such as the enhancement of biomineralization on a bone tissue engineering scaffold or the mimicking of the natural structure of the extracellular matrix (ECM). This ability is commonly referred to as "bioactivity". Materials sciences started to grow interest in it since the development of bioactive glasses by Larry Hench five decades ago. As the main goal in applications of biomedical devices and tissue scaffolds is to obtain a seamless tissue-material interface, achieving optimal bioactivity is essential for the success of most biomaterial-based tissue replacement and regenerative approaches. Polymers derived from lactic acid are largely adopted in the biomedical field, they are versatile, FDA approved and relatively cost-effective. However, as for many other widespread biomedical polymers, they are hydrophobic and lack the intrinsic ability of positively interacting with surrounding tissues. In the last decades scientists have studied many solutions to exploit the positive characteristics of polylactide-based materials overcoming this bottleneck at the same time. The efforts of this research fruitfully produced many effective tissue engineering technologies based on PLA and related biopolymers. This review aims to give an overview on the latest and most promising strategies to improve the bioactivity of lactic acid-based materials, especially focusing on biomolecule-free bulk approaches such as blending, copolymerization or composite fabrication. Avenues for future research to tackle current needs in the field are identified and discussed.

Polymer-Bioactive Glass Composite Filaments for 3D Scaffold Manufacturing by Fused Deposition Modeling: Fabrication and Characterization - Distler, Thomas; Fournier, Niklas; Grünewald, Alina; Polley, Christian; Seitz, Hermann; Detsch, Rainer; Boccaccini, Aldo R. (Frontiers in Bioengineering and Biotechnology, 2020)
Critical size bone defects are regularly treated by auto- and allograft transplantation. However, such treatments require to harvest bone from patient donor sites, with often limited tissue availability or risk of donor site morbidity. Not requiring bone donation, three-dimensionally (3D) printed implants and biomaterial-based tissue engineering (TE) strategies promise to be the next generation therapies for bone regeneration. We present here polylactic acid (PLA)-bioactive glass (BG) composite scaffolds manufactured by fused deposition modeling (FDM), involving the fabrication of PLA-BG composite filaments which are used to 3D print controlled open-porous and osteoinductive scaffolds. We demonstrated the printability of PLA-BG filaments as well as the bioactivity and cytocompatibility of PLA-BG scaffolds using pre-osteoblast MC3T3E1 cells. Gene expression analyses indicated the beneficial impact of BG inclusions in FDM scaffolds regarding osteoinduction, as BG inclusions lead to increased osteogenic differentiation of human adipose-derived stem cells in comparison to pristine PLA. Our findings confirm that FDM is a convenient additive manufacturing technology to develop PLA-BG composite scaffolds suitable for bone tissue engineering.
CRIS-Team Scopus Importer:2020-07-17
Keywords: 3D printing; 3D printing filaments; bioactive glass; bone tissue engineering; fused deposition modeling; polymer ceramic composites

Polymer/bioactive glass nanocomposites for biomedical applications: A review - Boccaccini, Aldo R.; Erol, Melek; Stark, Wendelin J.; Mohn, Dirk; Hong, Zhongkui; Mano, Joao F. (Composites Science and Technology, 2010)
Nanoscale bioactive glasses have been gaining attention due to their reported superior osteoconductivity when compared to conventional (micron-sized) bioactive glass materials. The combination of bioactive glass nanoparticles or nanofibers with polymeric systems enables the production of nanocomposites with potential to be used in a series of orthopedic applications, including scaffolds for tissue engineering and regenerative medicine. This review presents the state of art of the preparation of nanoscale bioactive glasses and corresponding composites with biocompatible polymers. The recent developments in the preparation methods of nano-sized bioactive glasses are reviewed, covering sol-gel routes, microemulsion techniques, gas phase synthesis method (flame spray synthesis), laser spinning, and electro-spinning. Then, examples of the preparation and properties of nanocomposites based on such inorganic bionanomaterials are presented, obtained using various polymer matrices, including polyesters such as poly(hydroxybutyrate), poly(lactic acid) and poly(caprolactone), and natural-based polymers such as polysaccharides (starch, chitin, chitosan) or proteins (silk fibroin, collagen). The physico-chemical, mechanical, and biological advantages of incorporating nanoscale bioactive glasses in such biodegradable nanocomposites are discussed and the possibilities to expand the use of these materials in other nanotechnology concepts aimed to be used in different biomedical applications are also highlighted. © 2010 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.polyme
Keywords: A. Bioactive glass; A. Nanocomposites; A. Nanoparticles; A. Particle-reinforced composites; B. Porosity/voids

Polymer-derived Biosilicate-C composite foams: In-vitro bioactivity, biocompatibility and antibacterial activity - Dogrul, Fulden; Nawaz, Qaisar; Elsayed, Hamada; Liverani, Liliana; Galusek, Dušan; Bernardo, Enrico; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2024)
Biosilicate/carbon composites were fabricated in the form of highly porous foams by the polymer-derived ceramic route, and their biological response was analysed. Two different commercial silicone polymers (a poly-methyl-siloxane, MK, and a polymethyl-phenyl-silsesquioxane, H44) were considered as a silica source, mixed with active fillers yielding Na2O, CaO and P2O5. The samples were heat treated either in air or in N2 atmosphere to obtain products resembling the known Biosilicate® glass-ceramic, with or without free carbon. All fabricated samples exhibited acellular in-vitro bioactivity upon immersion in SBF as well as antibacterial activity against S. aureus and E. coli. Direct contact cell viability test, assessed by using a WST-8 assay, indicated that both carbon-containing and carbon-free samples were cytocompatible.
CRIS-Team Scopus Importer:2024-03-29
Keywords: Antibacterial activity; biocompatibility; cell viability; Biosilicate glass-ceramic; Composites; Polymer-derived-ceramics; SiOC

Polymer-derived biosilicate®-like glass-ceramics: Engineering of formulations and additive manufacturing of three-dimensional scaffolds - Dogrul, Fulden; Ożóg, Paulina; Michálek, Martin; Elsayed, Hamada; Galusek, Dušan; Liverani, Liliana; Boccaccini, Aldo R.; Bernardo, Enrico (Materials, 2021)
Silicone resins, filled with phosphates and other oxide fillers, yield upon firing in air at 1100◦C, a product resembling Biosilicate® glass-ceramics, one of the most promising systems for tissue engineering applications. The process requires no preliminary synthesis of parent glass, and the polymer route enables the application of direct ink writing (DIW) of silicone-based mixtures, for the manufacturing of reticulated scaffolds at room temperature. The thermal treatment is later applied for the conversion into ceramic scaffolds. The present paper further elucidates the flexibility of the approach. Changes in the reference silicone and firing atmosphere (from air to nitrogen) were studied to obtain functional composite biomaterials featuring a carbon phase embedded in a Biosilicate®-like matrix. The microstructure was further modified either through a controlled gas release at a low temperature, or by the revision of the adopted additive manufacturing technology (from DIW to digital light processing).
CRIS-Team Scopus Importer:2021-09-24
Keywords: Additive manufacturing; Biosilicate® glass-ceramic; Digital light processing; Direct ink writing; Polymer-derived ceramics; SiOC

Polymeric Hydrogel Systems as Emerging Biomaterial Platforms to Enable Hemostasis and Wound Healing - Pourshahrestani, Sara; Zeimaran, Ehsan; Kadri, Nahrizul Adib; Mutlu, Nurshen; Boccaccini, Aldo R. (Advanced Healthcare Materials, 2020)
Broad interest in developing new hemostatic technologies arises from unmet needs in mitigating uncontrolled hemorrhage in emergency, surgical, and battlefield settings. Although a variety of hemostats, sealants, and adhesives are available, development of ideal hemostatic compositions that offer a range of remarkable properties including capability to effectively and immediately manage bleeding, excellent mechanical properties, biocompatibility, biodegradability, antibacterial effect, and strong tissue adhesion properties, under wet and dynamic conditions, still remains a challenge. Benefiting from tunable mechanical properties, high porosity, biocompatibility, injectability and ease of handling, polymeric hydrogels with outstanding hemostatic properties have been receiving increasing attention over the past several years. In this review, after shedding light on hemostasis and wound healing processes, the most recent progresses in hydrogel systems engineered from natural and synthetic polymers for hemostatic applications are discussed based on a comprehensive literature review. Most studies described used in vivo models with accessible and compressible wounds to assess the hemostatic performance of hydrogels. The challenges that need to be tackled to accelerate the translation of these novel hemostatic hydrogel systems to clinical practice are emphasized and future directions for research in the field are presented.
CRIS-Team Scopus Importer:2020-09-25
Keywords: adhesives; hemostasis; hemostats; injectable hydrogels; wound healing

Polymer (PCL) fibers with Zn-doped mesoporous bioactive glass nanoparticles for tissue regeneration - Nescakova, Zuzana; Kankova, Hana; Galuskova, Dagmar; Galusek, Dusan; Boccaccini, Aldo R.; Liverani, Liliana (International Journal of Applied Glass Science, 2021)
Composite fibrous membranes based on poly(ɛ-caprolactone) (PCL) and mesoporous bioactive glass nanoparticles (MBGNs) were fabricated by electrospinning. MBGNs and Zn-doped MBGNs prepared by microemulsion sol–gel method were successfully incorporated inside the polymeric fibers of 240 and 385 nm in diameter for undoped and Zn-doped PCL_MBGNs fibers, respectively. Thermal analysis showed that the concentration of MBGNs reached a maximum of around 21 wt% for Zn-doped MBGNs. Both PCL_MBGNs and PCL_MBGNs_Zn composite membrane exhibited bioactivity after immersion in simulated body fluid (SBF). X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) showed the evolution of composite membranes, confirming the formation of hydroxyapatite (HAp). However, the degradation products of membranes did not affect the viability and proliferation of murine stromal cells (ST-2) and thus the new fiber structures represent a suitable environment for cell adhesion. Therefore, the incorporation of mesoporous glass nanoparticles doped with therapeutically active Zn2+ ions inside the PCL fibers offers the possibility to create a multifunctional biomaterial suitable for drug delivery and tissue engineering.
CRIS-Team Scopus Importer:2021-07-30
Keywords: benign solvents; composite fibers; composites; electrospinning; mesoporous bioactive glass nanoparticles; poly(ɛ-caprolactone); tissue engineering; zinc

Polymers and Bioactive Compounds with a Macrophage Modulation Effect for the Rational Design of Hydrogels for Skin Regeneration - Sánchez, Mirna L.; Valdez, Hugo; Conde, Micaela; Viaña-Mendieta, Pamela; Boccaccini, Aldo R. (Pharmaceutics, 2023)
The development of biomaterial platforms for dispensing reagents of interest such as antioxidants, growth factors or antibiotics based on functional hydrogels represents a biotechnological solution for many challenges that the biomedicine field is facing. In this context, in situ dosing of therapeutic components for dermatological injuries such as diabetic foot ulcers is a relatively novel strategy to improve the wound healing process. Hydrogels have shown more comfort for the treatment of wounds due to their smooth surface and moisture, as well as their structural affinity with tissues in comparison to hyperbaric oxygen therapy, ultrasound, and electromagnetic therapies, negative pressure wound therapy or skin grafts. Macrophages, one of the most important cells of the innate immune system, have been described as the key not only in relation to the host immune defense, but also in the progress of wound healing. Macrophage dysfunction in chronic wounds of diabetic patients leads to a perpetuating inflammatory environment and impairs tissue repair. Modulating the macrophage phenotype from pro-inflammatory (M1) to anti-inflammatory (M2) could be a strategy for helping to improve chronic wound healing. In this regard, a new paradigm is found in the development of advanced biomaterials capable of inducing in situ macrophage polarization to offer an approach to wound care. Such an approach opens a new direction for the development of multifunctional materials in regenerative medicine. This paper surveys emerging hydrogel materials and bioactive compounds being investigated to induce the immunomodulation of macrophages. We propose four potential functional biomaterials for wound healing applications based on novel biomaterial/bioactive compound combination that are expected to show synergistic beneficial outcomes for the local differentiation of macrophages (M1–M2) as a therapeutic strategy for chronic wound healing improvement.
CRIS-Team Scopus Importer:2023-07-28
Keywords: biomaterials; inmunomodulation; macrophages M1–M2; polymers; wound-healing

Polymers for myocardial tissue engineering - Roether, Judith; Jawad, H.; Rai, Ranjana; Ali, N. N.; Harding, S. E.; Boccaccini, Aldo R. (CRC Press, 2013)
Cardiovascular disease (CVD) is the leading cause of death in the industrialized world (Lloyd-Jones et al. 2010). Heart attacks are the main cause of death in patients with CVD, although damage to heart muscle can also occur from infection, drugs, alcohol, chemotherapeutic agents, or because of congenital conditions. According to available statistical information (www.bhf.org.uk), approximately 30% of patients suffering from heart attacks each year die suddenly before reaching hospital. In the remaining patients who survive the initial acute event, the damage sustained to the heart may eventually develop heart failure. A heart attack, known as myocardial infarction (MI), occurs when one or more of the blood vessels supplying the heart suddenly occlude. These vessels are the coronary arteries, and when blocked abruptly, there is a sudden decrease in the supply of nutrients and oxygen to the portion of heart muscle supplied by the artery. If blood flow is not restored rapidly, the result is irreversible cell death within the affected part of the heart muscle.
CRIS-Team Scopus Importer:2022-08-05

Polyurethane foams electrophoretically coated with carbon nanotubes for tissue engineering scaffolds - Boccaccini, Aldo R.; et al. (Biomedical Materials, 2009)
Carbon nanotubes (CNTs) were deposited on the surfaces of polyurethane (PUR) foams by electrophoretic deposition (EPD). The parameters of EPD were optimized in order to obtain homogeneous CNT coatings on PUR foams and adequate infiltration of the three-dimensional (3D) porous network. The microstructure of the composites was investigated by high-resolution scanning electron microscopy (HRSEM), revealing that optimal quality of the coatings was achieved by an EPD voltage of 20 V. The thermal properties of the CNT-coated specimens, determined by thermogravimetric analysis (TGA), were correlated to the foam microstructure. In vitro tests in concentrated simulated body fluid (1.5 SBF) were performed to study the influence of the presence of CNTs on the bioactivity of PUR-based scaffolds, assessed by the formation of calcium phosphate (CaP) compounds, e.g. hydroxyapatite (HA), on the foam surfaces. It was observed that CNTs accelerate the precipitation of CaP, which is thought to be due to the presence of more nucleation centres for crystal nucleation and growth, as compared with uncoated foams. Polyurethane foams with CNT coating have the potential to be used as bioactive scaffolds in bone tissue engineering due to their high interconnected porosity, bioactivity and nanostructured surface topography. © 2009 IOP Publishing Ltd.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.polyur

Poly(ε-caprolactone)/bioactive glass composite electrospun fibers for tissue engineering applications - Piatti, Elisa; Miola, Marta; Liverani, Liliana; Verné, Enrica; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2023)
In this work, composite electrospun fibers containing innovative bioactive glass nanoparticles were produced and characterized. Poly(ε-caprolactone), benign solvents, and sol–gel B- and Cu-doped bioactive glass powders were used to fabricate fibrous scaffolds. The retention of bioactive glass nanoparticles in the polymer matrix, the electrospinnability of this novel solution and the obtained electrospun composites were extensively characterized. As a result, composite electrospun fibers characterized by biocompatibility, bioactivity, and exhibiting overall properties adequate for both hard and soft tissue engineering applications, have been produced. The addition of these bioactive glass nanoparticles was, indeed, able to impart bioactive properties to the fibers. Cell culture studies show promising results, demonstrating proliferation and growth of cells on the composite fibers. Wettability, degradation rate, and mechanical performance were also tested and are in line with previous results.
CRIS-Team Scopus Importer:2023-06-23
Keywords: benign solvents; bioactive glass; boron; composite; copper; electrospinning; poly(epsilon-caprolactone)

Poly(ε-caprolactone)/poly(glycerol sebacate) electrospun scaffolds for cardiac tissue engineering using benign solvents - Vogt, Lena; Ramos Rivera, Laura; Liverani, Liliana; Piegat, Agnieszka; El Fray, Miroslawa; Boccaccini, Aldo R. (Materials Science and Engineering C, 2019)
Electrospun fibers based on combinations of poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) have been studied for applications in cardiac tissue engineering. The aim of the present study is to demonstrate the fabrication of PCL and PGS prepolymer or mildly crosslinked PGS by electrospinning using less toxic solvents, like acetic acid, as opposed to conventional solvents such as chloroform or dichloromethane. The morphological and physiochemical properties and degradation susceptibility of the fiber mats were determined. A cell study using ST2 cells was performed to assess cytocompatibility. Neat PCL and PCL/PGS blends showed defect-free microstructures, whereby the average fiber diameter increased with the addition of PGS (0.8 ± 0.3 μm and 1.3 ± 0.7 μm, respectively). The mechanical properties were tested at 23 °C and 37 °C and showed higher values compared to native human myocardium. Degradation studies revealed a fast PGS degradation but the mildly cross-linked PGS resulted in acidification of the degradation medium. The biocompatibility was significantly increased when the samples were disinfected in 70% v/v ethanol in comparison to ultra-violet light disinfection. PCL/PGS fibers fabricated with acetic acid proved to be potentially suitable for application in cardiac tissue engineering based on their mechanical properties and biodegradability.
CRIS-Team Scopus Importer:2019-05-21
Keywords: Acetic acid; Cardiac patch; Cardiac tissue engineering; Electrospinning; Poly(glycerol sebacate); Poly(ε-caprolactone)

Porous bioactive glass micro- And nanospheres with controlled morphology: Developments, properties and emerging biomedical applications - Zheng, Kai; Sui, Baiyan; Ilyas, Kanwal; Boccaccini, Aldo R. (Materials Horizons, 2021)
In recent years, porous bioactive glass micro/nanospheres (PBGSs) have emerged as attractive biomaterials in various biomedical applications where such engineered particles provide suitable functions, from tissue engineering to drug delivery. The design and synthesis of PBGSs with controllable particle size and pore structure are critical for such applications. PBGSs have been successfully synthesized using melt-quenching and sol-gel based methods. The morphology of PBGSs is controllable by tuning the processing parameters and precursor characteristics during the synthesis. In this comprehensive review on PBGSs, we first overview the synthesis approaches for PBGSs, including both melt-quenching and sol-gel based strategies. Sol-gel processing is the primary technology used to produce PBGSs, allowing for control over the chemical compositions and pore structure of particles. Particularly, the influence of pore-forming templates on the morphology of PBGSs is highlighted. Recent progress in the sol-gel synthesis of PBGSs with sophisticated pore structures (e.g., hollow mesoporous, dendritic fibrous mesoporous) is also covered. The challenges regarding the control of particle morphology, including the influence of metal ion precursors and pore expansion, are discussed in detail. We also highlight the recent achievements of PBGSs in a number of biomedical applications, including bone tissue regeneration, wound healing, therapeutic agent delivery, bioimaging, and cancer therapy. Finally, we conclude with our perspectives on the directions of future research based on identified challenges and potential new developments and applications of PBGSs.
CRIS-Team Scopus Importer:2021-03-05

Porous bioactive glass microspheres prepared by flame synthesis process - Kraxner, Jozef; Michalek, Martin; Romero, Acacio Rincon; Elsayed, Hamada; Bernardo, Enrico; Boccaccini, Aldo R.; Galusek, Dušan (Materials Letters, 2019)
A scaleable, low cost processing method to prepare porous bioactive glass (BG) microspheres is presented. Glass powder with composition based on 45S5 BG and exhibiting irregularly shaped particles was fabricated by conventional melting. Glass powder was alkali activated to induce pore formation during the following flame synthesis step. Porous microspheres, with diameters ranging between 45 and 75 µm, were successfully prepared and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The porous bioactive glass microspheres are promising candidates for applications in bone regeneration, tissue engineering, and as carriers for controlled drug delivery.
CRIS-Team Scopus Importer:2019-09-24
Keywords: Alkaline activation; Bioactive glass; Flame synthesis; Porous microspheres

Porous Bioactive Nanofibers via Cryogenic Solution Blow Spinning and Their Formation into 3D Macroporous Scaffolds - Medeiros, Eudes Leonnan G.; Braz, Ana Leticia; Porto, Isaque Jeronimo; Menner, Angelika; Bismarck, Alexander; Boccaccini, Aldo R.; Lepry, William C.; Nazhat, Showan N.; Medeiros, Eliton S.; Blaker, Jonny J. (ACS Biomaterials Science and Engineering, 2016)
Keywords: bioactive composite; nanofibers; polylactide; solution blow spinning; thermally induced phase separation

Porous Biomaterials and Scaffolds for Tissue Engineering - Liverani, Liliana; Guarino, Vincenzo; La Carrubba, Vincenzo; Boccaccini, Aldo R. (Encyclopedia of Biomedical Engineering, 2019)
In the present article, an overview of the definition of tissue engineering and scaffold requirements is reported. In particular, scaffold porosity and its relevance for several tissue target regeneration is highlighted. Different scaffold fabrication techniques are reported and explained in details, highlighting advantages and disadvantages for all of these techniques, regarding the specific final applications.<br
CRIS-Team WoS Importer:2020-04-10
Keywords: Porosity; Scaffold fabrication techniques; Scaffolds; Tissue engineering

Porous magnesium-based scaffolds for tissue engineering - Yazdimamaghani, Mostafa; Razavi, Mehdi; Vashaee, Daryoosh; Moharamzadeh, Keyvan; Boccaccini, Aldo R.; Tayebi, Lobat (Materials Science and Engineering C, 2017)
Keywords: Biodegradation; Bone; Cartilage; Magnesium; Porous scaffolds

Positive effect of wrapping poly caprolactone/polyethylene glycol fibrous films on the mechanical properties of 45S5 bioactive glass scaffolds - Shi, Quan; Li, Zhi-Yong; Liverani, Liliana; Roether, Judith; Chen, Qiang; Boccaccini, Aldo R. (International Journal of Applied Ceramic Technology, 2018)
Keywords: electrospinning; mechanical properties; 45S5 bioactive glass scaffold; bone tissue engineering; poly caprolactone/polyethylene glycol film

Potential of laponite incorporated oxidized alginate–gelatin (ADA-GEL) composite hydrogels for extrusion-based 3D printing - Cai, Fei Fan; Heid, Susanne; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2020)
The concept of adding inorganic fillers into hydrogels to form hydrogel nanocomposites often provides advantageous properties which can be exploited for successful 3D biofabrication. In this study, a new composite hydrogel combining oxidized alginate–gelatin (ADA-GEL) hydrogel and laponite nanoclay as inorganic nanofiller was successfully developed and characterized. The results showed that the addition of 0.5% (wt/vol) laponite nanoplatelets improved the printability of ADA-GEL hydrogels enabling the fabrication of detailed structures since a low effect of material spreading and reduced tendency to pore closure appeared. Furthermore, a comparison of different needle types (cylindrical and conical; same inner diameter of 250 μm) in filament fusion test showed that the pattern dispensed by cylindrical tip has enhanced printing accuracy and pattern fidelity when compared with the pattern from conical tip. A glass flip test determined a processing window of 1–2 h after composite ink preparation. Overall, laponite/ADA-GEL hydrogel composites are confirmed as promising inks for 3D bioprinting.
CRIS-Team Scopus Importer:2020-12-11
Keywords: ADA-GEL; biomaterial; bioprinting; composite; hydrogel; laponite; nanoclay; scaffold; tissue engineering

Preconditioning of bioactive glasses before introduction to static cell culture: What is really necessary? - Hohenbild, Frederike; Arango Ospina, Marcela; Moghaddam, Arash; Boccaccini, Aldo R.; Westhauser, Fabian (Methods and Protocols, 2020)
Due to their high bioreactivity, the in-vitro analysis of bioactive glasses (BGs) can be challenging when it comes to maintaining a physiological pH. To improve BG biocompatibility, a heterogenic spectrum of preconditioning approaches, such as “passivation” of the BGs by incubation in cell culture medium, are used but have never been directly compared. In this study, the effect of passivation periods of up to 72 h on pH alkalization and viability of human bone marrow-derived mesenchymal stromal cells was evaluated to determine a time-efficient passivation protocol using granules based on the 45S5-BG composition (in wt%: 45.0 SiO2, 24.5 Na2 O, 24.5 CaO, 6.0 P2 O5) in different concentrations. pH alkalization was most reduced after passivation of 24 h. Cell viability continuously improved with increasing passivation time being significantly higher after passivation of at least 24 h compared to non-passivated 45S5-BG and the necessary passivation time increased with increasing BG concentrations. In this setting, a passivation period of 24 h presented as an effective approach to provide a biocompatible cell culture setting. In conclusion, before introduction of BGs in cell culture, different passivation periods should be evaluated in order to meet the respective experimental settings, e.g., by following the experimental protocols used in this study.
CRIS-Team Scopus Importer:2020-09-04
Keywords: 45S5 bioactive glass; Biocompatibility; Cytocompatibility; Cytotoxicity; Human bone marrow-derived mesenchymal stromal cells; Passivation

Pre-Crosslinking with Hydrogel Microparticles Enhances the Printability of Alginate-Based Inks - Hazur, Jonas; Röder, Jonas; Czwalinna, Jonas; Schubert, Dirk W.; Boccaccini, Aldo R. (Macromolecular Materials and Engineering, 2023)
The main challenge in extrusion-based bioprinting is to develop inks which must comprise a manifold of characteristics before, during, and after printing. To tackle the challenge of good shape fidelity and printability of low concentration inks, in this study hydrogel microparticles (HMPs) are proposed to produce internally pre-crosslinked inks. Alginate (Alg) and oxidized alginate (OA)-based HMPs are fabricated and used as Ca2+-releasing reservoirs. OA HMPs are used to demonstrate the versatility of this approach and to show its suitability also for chemically modified alginate. Embedded in either fresh Alg or OA solution, HMPs are used to pre-crosslink the inks. Rheological measurements revealed that HMP pre-crosslinking increases the yield stress and viscosity while reducing the loss angle of bioinks. Moreover, printing experiments reveal that being able to tailor rheological properties is an effective tool to improve printability. Furthermore, pre-crosslinking significantly alters the hydogel internal microstructure. In vitro studies show that NIH/3T3 cells proliferate in HMP pre-crosslinked bioinks modified with gelatin. Altogether, a low-cost and easy to use setup to prepare HMPs is presented and for the first time, the possibility of using such HMPs as pre-crosslinking agent to tailor the printability of alginate-based bioinks is demonstrated.
CRIS-Team Scopus Importer:2023-08-18
Keywords: alginate; bioprinting; cross-linking; gelatin; oxidized alginate

Preface of the Special Issue ‘ESB 2017’ - Chatzinikolaidou, Maria; Boccaccini, Aldo R. (Journal of Materials Science: Materials in Medicine, 2018)
CRIS-Team Scopus Importer:2022-08-05

Preface: Syntactic and composite foams special section - Gladysz, G. M.; Chawla, K. K.; Boccaccini, Aldo R. (Journal of Materials Science, 2012)

Preface: Vitrification and geopolymerization of industrial wastes - Ma Rincon, Jesus; Jordan, Manuel; Boccaccini, Aldo R. (Materials Letters, 2019)
CRIS-Team Scopus Importer:2019-10-15

Preliminary Studies for One-Step Fabrication of Metallic Iron-Based Coatings on Magnesium as Temporary Protection in Biodegradable Medical Application - Yang, Yuyun; Shi, Zizhong; Cui, Xiufang; Liu, Yuejun; Jin, Guo; Virtanen, Sannakaisa; Boccaccini, Aldo R.; She, Peng (Frontiers in Materials, 2021)
Iron and magnesium are being considered as promising candidates for biodegradable materials in medical applications, both materials having their specific advantages and challenges. A hybrid of metallic iron and magnesium in a layered composite is studied in the present work, to combine the merits of both metals. A single-step dip-coating method was employed to prepare the layered composite material. Morphology, composition, crystal structure and corrosion behavior of the Mg/Fe sheet were assessed by SEM, EDX, XRD, and electrochemical measurements. The Mg/Fe layered composite sheet is composed of the magnesium substrate, a 1-2 mu m metallic iron coating, and a pompon-like Mg(OH)(2)/MgO top layer. Long-term open-circuit potential measurements revealed that the Mg/Fe sheet samples exhibit a "self-healing" effect in Dulbecco's modified Eagle's medium.
CRIS-Team WoS Importer:2021-12-31

Premature degradation of poly(α-hydroxyesters) during thermal processing of Bioglass® containing composites - Blaker, Jonny J.; Bismarck, Alexander; Boccaccini, Aldo R.; Young, Anne M.; Nazhat, Showan N. (Acta Biomaterialia, 2010)
Bioactive, biodegradable composites are increasingly being explored as bone replacement materials and as scaffolds for tissue engineering. Their properties are not only dependent on the properties of the filler and matrix, but are also determined by their interaction. This study investigated the effect on poly(d,l-lactide) (PDLLA) matrix when processed at high-temperatures in the presence of Bioglass® particulate filler. Composites with different filler contents were compounded at elevated temperatures by co-extrusion followed by compression moulding and compared with composites of similar composition prepared by thermally induced phase separation (TIPS), a low-temperature processing route. It was found that the inclusion of Bioglass® in PDLLA under elevated temperatures resulted in the degradation of the matrix, leading to a reduction in the mechanical properties of the composites and in the molecular weight of the matrix. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of a peak at 1600 cm-1 in the composite material, particularly when processed at elevated temperatures, whereas no peak at this wavelength was discernible for the pure PDLLA. Furthermore, time-based ATR-FTIR spectra taken at elevated temperatures on the TIPS-processed composites showed an increase in the intensity of the peak at 1600 cm-1 and a concomitant reduction of the Cdouble bond, longO stretch peak at 1745 cm-1 with time. This suggested the formation of a carboxylate salt by-products as a consequence of a reaction at the interface between the Bioglass® filler and the PDLLA matrix. Therefore, the results confirmed that this degradation was not solely due to shear effects during the extrusion process. This work thereby supports the assertion that, in the presence of Bioglass® filler particles, poly(α-hydroxyester)-based composites should not be processed at elevated temperatures. © 2009 Acta Materialia In
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.premat
Keywords: Bioactive glass; Biodegradable composite; Bioglass; Scaffolds; Silica

Preparation and characterisation of gallium releasing 3-D alginate coated 45S5 Bioglass® based scaffolds for bone tissue engineering - Mourino, Viviana; Newby, Phillipa; Boccaccini, Aldo R. (Advanced Engineering Materials, 2010)
The aim of this work was to develop functional three-dimensional scaffolds based on Bioglass® derived glass-ceramics for bone tissue engineering (TE) with prophylaxis effect against infections. The highly porous scaffolds were fabricated by the foam replication technique and then coated with sodium alginate crosslinked with Ga3+. It was confirmed that the polymer coating did not affect the interconnectivity of the scaffold pore structure. The resulting composite scaffold exhibited antibacterial effect and improved mechanical properties as well as high bioactivity. The novel Ga3p loaded 45S5 Bioglass1-based scaffolds coated with alginate are promising candidates for bone TE applications. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.prepar

Preparation and characterization of 45S5 bioactive glass-based scaffolds loaded with PHBV microspheres with daidzein release function - Macias-Andres, Victor I.; Li, Wei; Aguilar-Reyes, Ena A.; Ding, Yaping; Roether, Judith; Harhaus, Leila; Leon-Patino, Carlos A.; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2017)
Keywords: 45S5 bioactive glass; Bone tissue engineering; Daidzein; Drug delivery; PHBV; Scaffold

Preparation and characterization of aligned porous PCL/zein scaffolds as drug delivery systems via improved unidirectional freeze-drying method - Fereshteh, Zeinab; Fathi, Mohammadhossein; Bagri, Akbar; Boccaccini, Aldo R. (Materials Science and Engineering C, 2016)
Keywords: Aligned PCL/zein scaffolds; Controlled release; Drug delivery; Freeze-drying; Protein release

Preparation and characterization of Bioglass®-based scaffolds reinforced by poly-vinyl alcohol/microfibrillated cellulose composite coating - Bertolla, L.; Dlouhy, I.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2014)
The present work deals with the preparation and mechanical characterization of Bioglass-based porous scaffolds reinforced by a composite coating constituted by polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC). Samples were produced by foam replication process, using a novel ethanol-based Bioglass slurry. The addition of PVA/MFC coating led to a 10 fold increase of compressive strength and a 20 fold increase of tensile strength in comparison with non-coated scaffolds. SEM observations of broken struts surfaces proved the reinforcing and toughening effect of the composite coating which were ascribed to crack bridging and fracture of cellulose fibrils. The mechanical properties of the coatings were investigated by tensile testing of PVA/MFC composite stripes. The stirring time of the PVA/MFC solution came out as a crucial parameter in order to achieve a more homogeneous dispersion of the fibers and therefore enhanced strength and stiffness. © 2014 Elsevier Ltd.
Keywords: Bioceramics; Composite coating; Polymer coating; Porous materials

Preparation and characterization of electrosprayed daidzein-loaded PHBV microspheres - Scheithauer, Ellen Corinna; Li, Wei; Ding, Yaping; Harhaus, Leila; Roether, Judith; Boccaccini, Aldo R. (Materials Letters, 2015)
Given that hormone therapy of osteoporosis with estrogen and progesterone may have potential negative side effects, there is a strong need of developing alternative solutions. Possible therapy alternatives involve the use of phytoestrogens such as daidzein. In this study, daidzein-loaded poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres were prepared using electrospraying. The obtained microspheres had uniform surface morphology, and narrow particle size distribution with mean particle size of 4.8 μm. Daidzein was determined to be in amorphous state in the PHBV microspheres by differential scanning calorimetry analysis. Encapsulated daidzein was released with a low initial burst release (7.6% at 1 h) followed by a sustained release over a period of 3 days. The developed PHBV microspheres with daidzein delivery function have potential applications in the treatment of osteoporosis and for bone tissue engineerin
Keywords: Bone tissue engineering; Daidzein; Drug delivery; Electrospraying; Osteoporosis; PHBV microspheres

Preparation and Characterization of Electrospun Blend Fibrous Polyethylene Oxide:Polycaprolactone Scaffolds to Promote Cartilage Regeneration - Mirzaei, Zeynab; Kuth, Sonja; Schubert, Dirk W.; Detsch, Rainer; Roether, Judith; Blunk, Torsten; Kordestani, Soheila S.; Boccaccini, Aldo R. (Advanced Engineering Materials, 2020)
Fibrous scaffolds can be used to mimic the structure of cartilage extracellular matrix aiming at cartilage regeneration through optimal utilization of such scaffolds and chondrogenic cells. Herein, different types of fibrous structures are manufactured through electrospinning of blends of polyethylene oxide (PEO) and polycaprolactone (PCL), and the physical and chemical characteristics of the produced fiber mats are investigated. The amount of PEO influenced hydrophilicity, biodegradability, and mechanical properties of the blend fibers. To assess the cytotoxicity and biocompatibility of the scaffolds as well as the effect of fiber orientation, in vitro cell culture studies with a chondrogenic cell line (ATDC5) are conducted. The results show no cytotoxicity of the developed fibrous structures. A promising fibrous scaffold technology is presented with potential applications in cartilage tissue engineering.
CRIS-Team WoS Importer:2020-05-29

Preparation and characterization of fibrous chitosan-glued phosphate glass fiber scaffolds for bone regeneration - Zheng, Kai; Wu, Zhaoying; Wei, Jie; Russel, Christian; Liang, Wen; Boccaccini, Aldo R. (Journal of Materials Science: Materials in Medicine, 2015)
Phosphate glass fibers (PGF) have emerged as promising building blocks for constructing bone scaffolds. In this study, fibrous scaffolds (PGFS) were fabricated using a facile binding method at room temperature. PGFS exhibited an extracellular matrix-like morphology and were composed of PGF as matrix and chitosan as the natural binding glue. They showed an interconnected porous structure with a porosity of 87 % and pore size of 100–500 µm. PGFS exhibited the typical compressive stress–strain behaviour of highly porous, low-density, open-cell scaffolds. Their yield stress and modulus were 0.38 and 2.84 MPa, respectively, with the strength being higher than the lower bound of the compressive strength of cancellous bone. PGFS were degradable and the weight loss was about 25 % after immersion in stimulated body fluid (SBF) for 28 days. In addition, the yield stress and the modulus decreased with increasing immersion time in SBF. Apatite formation could be detected on the surface of PGFS within 7 days of immersion in SBF. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay indicated that PGFS were non-cytotoxic against bone marrow stromal cells (bMSCs) after culture for up to 72 h. These results suggest that PGFS could be promising scaffolds for bone regeneration applications.

Preparation and characterization of mesoporous calcium-doped silica-coated TiO2 scaffolds and their drug releasing behavior - Sengottuvelan, Abirami; Mederer, Marco; Boccaccini, Aldo R. (International Journal of Applied Ceramic Technology, 2018)
Keywords: Bioactivity; Drug release; Ibuprofen; Mesoporous calcium silica coatings; Scaffold; Titania

Preparation and characterization of mesoporous calcium-doped silica-coated TiO2 scaffolds and their drug releasing behavior - Sengottuvelan, Abirami; Mederer, Marco; Boccaccini, Aldo R. (International Journal of Applied Ceramic Technology, 2018)
Keywords: titania; bioactivity; ibuprofen; drug release; scaffold; mesoporous calcium silica coatings

Preparation and characterization of novel poly (lactic acid)/calcium oxide nanocomposites by electrospinning as a potential bone tissue scaffold - Canales, Daniel; Moyano, Dominique; Alvarez, Fabian; Grande-Tovar, Carlos David; Valencia-Llano, Carlos H.; Peponi, Laura; Boccaccini, Aldo R.; Zapata, Paula A. (Biomaterials Advances, 2023)
Calcium oxide nanoparticles (n-CaO) ca. 22 nm were obtained from eggshell waste. The n-CaO was incorporated into the PLA matrix in 10 and 20 wt% of filler content by electrospinning process to get PLA/n-CaO fibers with homogenous morphology and diameter as a potential use in scaffold for bone tissue regeneration. The incorporation of n-CaO into PLA modifies the mechanical properties, having a reinforcement effect on the matrix. The Young modulus for PLA/n-CaO nanocomposites increased between 122 and 138 % concerning neat PLA fibers, showing a more rigid behavior. The PLA/n-CaO nanocomposite fibers showed in vitro bioactivity, capable of inducing the precipitation of hydroxyapatite (HA) layer in the fiber surface after seven days in SBF solution. The biocidal and biological properties of PLA/n-Cao with 20 wt% showed a 30 % reduction in bacterial viability against S. aureus and 11 % against E. coli after 6 h of bacterial exposure. Furthermore, the fibers did not show a cytotoxic effect on the bone marrow ST-2 cell line, allowing cell adhesion and proliferation in the RPMI medium. The PLA/n-CaO with 20 wt% of nanoparticles showed a higher capacity to promote osteogenic differentiation, significantly increasing the alkaline phosphatase (ALP) expression after seven days compared to PLA and cell control. The in vivo analysis corroborated the biocompatibility of the prepared scaffolds; the presence of n-CaO in PLA reduced the formation of fibrous encapsulation of the material, improving the healing process. These results validated using n-CaO to enhance the functionality of polymer matrices as a PLA, bringing bioactive, biocide, and biocompatible properties, opening a new and interesting route to develop new biomaterials as a scaffold for bone tissue engineering.
CRIS-Team Scopus Importer:2023-08-18
Keywords: CaO nanoparticles; Electrospun fiber; Functional biomaterials; PLA-based nanocomposites; Tissue engineering

Preparation and characterization of PHBV microsphere/45S5 bioactive glass composite scaffolds with vancomycin releasing function - Li, Wei; Ding, Yaping; Rai, Ranjana; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (Materials Science and Engineering C, 2014)
PHBV microsphere/45S5 bioactive glass (BG) composite scaffolds with drug release function were developed for bone tissue engineering. BG-based glass-ceramic scaffolds with high porosity (94%) and interconnected pore structure prepared by foam replication method were coated with PHBV microspheres (nominal diameter = 3.5 μm) produced by water-in-oil-in-water double emulsion solvent evaporation method. A homogeneous microsphere coating throughout the porous structure of scaffolds was obtained by a simple dip coating method, using the slurry of PHBV microspheres in hexane. Compressive strength tests showed that the microsphere coating slightly improved the mechanical properties of the scaffolds. It was confirmed that the microsphere coating did not inhibit the bioactivity of the scaffolds in SBF. Hydroxyapatite crystals homogeneously grew not only on the struts of the scaffolds but also on the surface of microspheres within 7 days of immersion in SBF. Vancomycin was successfully encapsulated into the PHBV microspheres. The encapsulated vancomycin was released with a dual release profile involving a relatively low initial burst release (21%) and a sustained release (1 month), which is favorable compared to the high initial burst release (77%) and short release period (4 days) measured on uncoated scaffolds. The developed bioactive composite scaffold with drug delivery function has thus the potential to be used advantageously in bone tissue engineerin
Keywords: tissue engineering; vancomycin; PHBV; scaffold; drug delivery; Bioglass

Preparation and characterization of PHBV microsphere/45S5 bioactive glass composite scaffolds with vancomycin releasing function - Li, Wei; Ding, Yaping; Rai, Ranjana; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (Materials Science and Engineering C, 2014)
PHBV microsphere/45S5 bioactive glass (BG) composite scaffolds with drug release function were developed for bone tissue engineering. BG-based glass-ceramic scaffolds with high porosity (94%) and interconnected pore structure prepared by foam replication method were coated with PHBV microspheres (nominal diameter = 3.5 μm) produced by water-in-oil-in-water double emulsion solvent evaporation method. A homogeneous microsphere coating throughout the porous structure of scaffolds was obtained by a simple dip coating method, using the slurry of PHBV microspheres in hexane. Compressive strength tests showed that the microsphere coating slightly improved the mechanical properties of the scaffolds. It was confirmed that the microsphere coating did not inhibit the bioactivity of the scaffolds in SBF. Hydroxyapatite crystals homogeneously grew not only on the struts of the scaffolds but also on the surface of microspheres within 7 days of immersion in SBF. Vancomycin was successfully encapsulated into the PHBV microspheres. The encapsulated vancomycin was released with a dual release profile involving a relatively low initial burst release (21%) and a sustained release (1 month), which is favorable compared to the high initial burst release (77%) and short release period (4 days) measured on uncoated scaffolds. The developed bioactive composite scaffold with drug delivery function has thus the potential to be used advantageously in bone tissue engineering. © 2014 Elsevier B.V. All rights reserved.
Keywords: Bioglass; drug delivery; PHBV; scaffold; tissue engineering; vancomycin

Preparation and characterization of sintered bioactive borate glass tape - Sengupta, Susanta; Michalek, Martin; Liverani, Liliana; Švančárek, Peter; Boccaccini, Aldo R.; Galusek, Dušan (Materials Letters, 2021)
Non-aqueous tape casting was used to prepare flexible green tapes from borate glass (1393B3) particles. The tapes were sintered at 550, 575, 600 °C: dense tapes were prepared at 600 °C. In-vitro bioactivity in simulated body fluid (SBF) of tapes sintered at different temperatures was evaluated. SEM, FTIR and XRD results showed slow degradation of dense borate glass tape in SBF compared to the non-dense tapes sintered at different temperatures. Formation of HCA (hydroxy carbonated apatite) on sample surfaces was confirmed after 7D in SBF.
CRIS-Team Scopus Importer:2020-10-30
Keywords: Bioactivity; Borate bioactive glass; Densification; Tape casting

Preparation and characterization of vancomycin releasing PHBV coated 45S5 Bioglass®-based glassceramic scaffolds for bone tissue engineering - Li, Wei; Nooeaid, Patcharakamon; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2014)
Porous 45S5 Bioglass®-based glass-ceramic scaffolds with high porosity (96%) and interconnected pore structure (average pore size 300μm) were prepared by foam replication method. In order to improve the mechanical properties and to incorporate a drug release function, the scaffolds were coated with a drug loaded solution, consisting of PHBV and vancomycin. The mechanical properties of the scaffolds were significantly improved by the PHBV coating. The bioactivity of scaffolds upon immersion in SBF was maintained in PHBV coated scaffolds although the formation of hydroxyapatite was slightly retarded by the presence of the coating. The encapsulated drug in coated scaffolds was released in a sustained manner (99.9% in 6 days) as compared to the rapid release (99.5% in 3 days) of drug directly adsorbed on the uncoated scaffolds. The obtained drug loaded and bioactive composite scaffolds represent promising candidates for bone tissue engineering applications. © 2013 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2014.tech.IW.LM.prepar
Keywords: 45S5 Bioglass; Drug release; Mechanical properties; PHBV; Scaffold

Preparation and characterization of vancomycin releasing PHBV coated 45S5 Bioglass®-based glass-ceramic scaffolds for bone tissue engineering - Li, Wei; Nooeaid, Patcharakamon; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2014)
Porous 45S5 Bioglass®-based glass–ceramic scaffolds with high porosity (96%) and interconnected pore structure (average pore size 300 μm) were prepared by foam replication method. In order to improve the mechanical properties and to incorporate a drug release function, the scaffolds were coated with a drug loaded solution, consisting of PHBV and vancomycin. The mechanical properties of the scaffolds were significantly improved by the PHBV coating. The bioactivity of scaffolds upon immersion in SBF was maintained in PHBV coated scaffolds although the formation of hydroxyapatite was slightly retarded by the presence of the coating. The encapsulated drug in coated scaffolds was released in a sustained manner (99.9% in 6 days) as compared to the rapid release (99.5% in 3 days) of drug directly adsorbed on the uncoated scaffolds. The obtained drug loaded and bioactive composite scaffolds represent promising candidates for bone tissue engineering applications.
Keywords: Drug release; 45S5 Bioglass®; PHBV; Mechanical properties; Scaffold

Preparation and in vitro characterization of silver-doped bioactive glass nanoparticles fabricated using a sol-gel process and modified Stöber method - El-Rashidy, Aiah A.; Waly, Gihan; Gad, Ahmed; Hashem, Azza A.; Balasubramanian, Preethi; Kaya, Seray; Boccaccini, Aldo R.; Sami, Inas (Journal of Non-Crystalline Solids, 2018)
The study aimed at preparing Ag-doped bioactive glass (BG) nanoparticles containing 5 wt% Ag2O using a new modified Stöber method (Ag-BGm) and the conventional sol-gel method (Ag-BGsg). The aim of employing the new Ag-doping mechanism is to implement a relatively short process to incorporate higher concentration of silver (Ag+) ions in an attempt to combine the antibacterial activity of silver with the bioactivity of BG. SEM and TEM micrographs showed that Ag-BGm nanoparticles were mondispersed, and spherical, while Ag-BGsg nanoparticles were formed of highly porous irregular agglomerated particles. A significantly higher silicon, calcium and silver ions release from the Ag-BGsg was evident, as compared to Ag-BGm, in deionized water (DIW). In vitro bioactivity test showed rapid bioactive properties of Ag-BGsg in simulated body fluid (SBF), as compared to Ag-BGm. Both BGs showed antibacterial effect against E. coli O157: H7 wild type strain 93111 and S. aureus ATCC 25923 as evident by the disc diffusion assay, but Ag-BGsg showed significantly higher mean inhibition zone compared to Ag-BGm. It may be concluded that both Ag-BGsg and Ag-BGm has the potential to be used as bone substitute materials with the Ag-BGsg being more promising due to its high bioactivity and antibacterial effect.
CRIS-Team Scopus Importer:2022-08-05
Keywords: Antibacterial; Bioactive glass; Bioactivity; In vitro; Modified Stöber; Silver

Preparation of BaTiO3 nanotube arrays, CoFe2O4 nanoparticles and their composites - Tan, W. K.; Oura, K.; Kawamura, Go; Boccaccini, Aldo R.; Matsuda, Atsunori (ECS Transactions, 2018)
Multiferroic nanocomposites which possess both ferroelectric and ferromagnetic properties are attracting much attention because of their scientific interest and significant technological promise in novel multifunctional devices. In this work, multiferroic nanocomposites are targeted by anodization of Ti sheets to get TiO2 nanotubes followed by hydrothermal treatment to form BaTiO3 nanotube arrays, which were then used as a component to fabricate multiferroic nanocomposites through electrophoretic deposition (EPD) of CoFe2O4 nanoparticles into the tubular pores. Successful formation of BaTiO3 nanotube arrays and CoFe2O4 nanoparticles were achieved. The morphologies and crystal structure of BaTiO3 nanotube arrays were analyzed by a scanning electron microscope (SEM) and an X-ray diffractometer (XRD). Simulation of EPD of CoFe2O4 nanoparticles into BaTiO3 nanotube arrays was also performed in order to predict and improve the susceptibility of forming a desired composite layer.
CRIS-Team Scopus Importer:2022-08-05

Preparation of compact alginate films for 2D in vitro studies: Challenges and strategies for improvement - Schöbel, Lisa; Karakaya, Emine; Detsch, Rainer; Boccaccini, Aldo R. (Materials Letters, 2023)
Alginate-based hydrogels show high biocompatibility and therefore are broadly used for cell cultivation and tissue engineering approaches in general. When hydrogel films for cell seeding were prepared by following published protocols, attached but inhomogeneously distributed cells were observed, which was attributed to the fact that casted hydrogel films were uneven and irregularly shaped. The causes of these irregularities resulting in an inhomogeneous cell distribution, e.g., due to accumulation of cells in cracks, were investigated. This study established a universal protocol for preparing planar hydrogel films that allow a homogenous cell distribution by varying several parameters such as alginate type, freezing, and crosslinking conditions. This finding can be applied to investigations of two-dimensional cell-material interactions of advanced alginate-based materials, e.g., when coupled with peptides.
CRIS-Team Scopus Importer:2023-03-17
Keywords: Crosslinking; Fibroblasts; Hydrogels; In vitro cell culture; Sodium alginate

Preparation of low melting temperature glass-ceramics from municipal waste incineration fly ash - Yang, Jiakuan; Xiao, Bo; Boccaccini, Aldo R. (Fuel, 2009)
Glass-ceramics have been prepared from air pollution control residues (fly ash) of a municipal solid waste incineration (MSWI) plant in southern China. The use of additives was investigated in order to decrease the melting temperature of the waste and thus to reduce the costs of production of glass-ceramics from the vitrified waste. Results showed that the melting temperature can be decreased significantly from 1500 to 1200 °C, which was achieved by combining the MSWI fly ash with silica sand powder and a Fe2O3-rich and CaO-rich iron slag to form a glass in the SiO2-CaO-Al2O3-Fe2O3 quaternary phase system. Sodium carbonate and borax were used as fluxing agents and TiO2 of chemical grade was added as a nucleation agent. The main crystalline phase in both high and low melting temperature glass-ceramics was found to be diopside (Fe-bearing), and the microstructure exhibited the presence of fine crystals of size in the range 100-200 nm which developed at crystallization temperatures in the range 800-900 °C for 1-2 h. The leaching behaviour of the glass-ceramic materials was tested, and it was found to be lower than that of a cement-stabilized body that was fabricated using the same waste for comparison. The results demonstrate the feasibility of reusing MSWI fly ash for glass-ceramic production at relatively low melting temperature, e.g. in a less energy-intensive process, as a viable approach for tackling the problem of hazardous MSWI residues. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.prepar
Keywords: Fly ash; Glass-ceramic; Municipal solid waste

Preparation of ZSM-5 zeolite membranes by combined hydrothermal synthesis and electrophoretic deposition - Negishi, Hideyuki; Reuß, Stephanie; Schwieger, Wilhelm; Boccaccini, Aldo R. (Key Engineering Materials, 2015)
The preparation of a ZSM-5 zeolite membrane on porous stainless steel disk by hydrothermal synthesis with electrophoretic deposition (EPD) as a seeding method was investigated. Micron size ZSM-5 crystal powder was seeded by EPD on the support disk by using ZSM-5 powder dispersed in ethanol. The seeded amounts were easily controlled by the deposition time during EPD. The membrane after secondary growth had a low amount of zeolite in comparison with the in situ seeding method and the permeance of single gas such as He, N2 and CO was also low in comparison with that of the in situ seeding method.
Keywords: Electrophoretic deposition (EPD); Permeance; Secondary growth; Seeding; Zeolite membrane

Pressure assisted flash sintering of Mn-Co based spinel coatings for solid oxide electrolysis cells (SOECs) - Javed, Hassan; Saunders, Theo; Reece, Michael John; Zanchi, Elisa; Sabato, Antonio Gianfranco; Boccaccini, Aldo R.; Smeacetto, Federico (Ceramics International, 2021)
Pressure assisted flash sintering was used to process Mn-Co-Cu based spinel coatings, electrophoretically deposited on a Crofer22APU interconnect. This method resulted in highly dense coatings, heat-treated for only a short duration (<10 min) at temperatures lower than conventional sintering temperatures. The electrophoretically deposited coatings showed no delamination or cracks after flash sintering at high heating rates (>200 °C/min). The high heating rate promoted Cu modified Mn-Co spinel and limited the formation of a Cr-oxide scale on the Crofer22APU substrate. Flash sintering was found to be a promising and time efficient sintering technique to overcome some of the issues related to low coating density and oxide scale formation in solid oxide electrolysis cell conditions.
CRIS-Team Scopus Importer:2021-03-26
Keywords: EPD; Flash sintering; Protective coatings; SOEC; SOFC

Pressureless spark plasma–sintered Bioglass® 45S5 with enhanced mechanical properties and stress–induced new phase formation - Bertolla, Luca; Dlouhy, Ivo; Tatarko, Peter; Viani, Alberto; Mahajan, Amit; Chlup, Zdenek; Reece, Michael J.; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2017)
Keywords: Bioglass; Biomaterials; Mechanical properties; Spark plasma sintering

Primary osteoblasts, osteoblast precursor cells or osteoblast-like cell lines: Which human cell types are (most) suitable for characterizing 45S5-bioactive glass? - Wilkesmann, Sebastian; Fellenberg, Joerg; Nawaz, Qaisar; Reible, Bruno; Moghaddam, Arash; Boccaccini, Aldo R.; Westhauser, Fabian (Journal of Biomedical Materials Research Part A, 2019)
The question how bioactive glasses (BGs) influence the viability and osteogenic differentiation of human osteogenic cells has already been addressed by several studies. However, a literature review revealed great differences in the type of cells used for these experiments. Primary human osteoblasts (hOBs) represent the desired standard, but possess the limitation of patient variability and time-consuming isolation protocols. Therefore, several alternative cell types have been used including primary mesenchymal stromal cells (BMSCs) and the "osteoblast-like" cell lines MG-63, Saos-2, HOS, and U2OS. The aim of our study was the identification of the cell type most suitable for tissue engineering projects involving BGs by comparative analysis of cell viability and osteogenic differentiation in response to crystallized 45S5-BG. We observed that hOBs, BMSCs, and MG-63 cells were resistant to 45S5-BG induced cytotoxicity, while the viability of Saos-2, HOS, and U2OS cells was significantly reduced. In addition, we detected alkaline phosphatase activity, except in U2OS cells, that increased upon 45S5-BG cocultivation, demonstrating the induction of osteogenic differentiation. Our data and the fact that the donor-dependent variations can be avoided when using MG-63 cells suggest that these are a promising alternative to primary cells and remain an important cell line for future BG related studies.
CRIS-Team WoS Importer:2019-12-17

Proangiogenic effects of tumor cells on endothelial progenitor cells vary with tumor type in an in vitro and in vivo rat model. - An, Ran; Schmid, Rafael; Klausing, Anne; Robering, Jan Willem; Weber, Manuel; Bäuerle, Tobias; Detsch, Rainer; Boccaccini, Aldo R.; Horch, Raymund E.; Boos, Anja; Weigand, Annika (The FASEB Journal, 2018)
Endothelial progenitor cells (EPCs) contribute to neovascularization in tumors. However, the relationship of EPCs and tumor-induced angiogenesis still remains to be clarified. The present study aimed at investigating the influence of 4 different tumor types on angiogenic properties of EPCs in an in vitro and in vivo rat model. It could be demonstrated that in vitro proliferation, migration, and angiogenic abilities and genetic modifications of EPCs are controlled in a tumor-type-dependent manner. The proangiogenic effect of mammary carcinoma, osteosarcoma, and rhabdomyosarcoma cells was more pronounced compared to colon carcinoma cells. Coinjection of encapsulated tumor cells, especially mammary carcinoma cells, and EPCs in a rat model confirmed a contributing effect of EPCs in tumor vascularization. Cytokines secreted by tumors such as monocyte chemoattractant protein 1, macrophage inflammatory protein 2, and TNF-related apoptosis-inducing ligand play a pivotal role in the tumor cell-EPC interaction, leading to enhanced migration and angiogenesis. With the present study, we were able to decipher possible underlying mechanisms by which EPCs are stimulated by tumor cells and contribute to tumor vascularization. The present study will contribute to a better understanding of tumor-induced vascularization, thus facilitating the development of therapeutic strategies targeting tumor-EPC interactions.-An, R., Schmid, R., Klausing, A., Robering, J. W., Weber, M., Bäuerle, T., Detsch, R., Boccaccini, A. R., Horch, R. E., Boos, A. M., Weigand, A. Proangiogenic effects of tumor cells on endothelial progenitor cells vary with tumor type in an in vitro and in vivo rat model.

Process- and topography-related cell viability on laser sintered polypropylene - Schlicht, Samuel; Detsch, Rainer; Nawaz, Qaisar; Boccaccini, Aldo R.; Drummer, Dietmar (8th China-Europe Symposium on Biomaterials in Regenerative Medicine, 2024)
Purpose New manufacturing techniques, such as laser sintering of polymers, enable new biomedical applications. These new processes can also change the surface properties of materials. The relationship between the material surface and specific tissue cells can be very different. The shape and structure of biomaterial surfaces affect how cells interact with them. The objective of this study is to investigate the interaction between cells and different laser- polypropylene (PP) surfaces. This enables the correlation of processing conditions in laser-based additive manufacturing and the cell-material interaction, which is a significant prerequisite to the additive manufacturing of components with optimised surface properties for enhancing cell behaviour. Methods and Results Laser sintering of semi crystalline thermoplastics with a particular focus on polyolefines represents a promising approach to the manufacturing of geometrically complex implants with targeted mechanical properties. Constituting a fundamental prerequisite to their application, the viability and proliferation of cells in contact with such implants is of significant relevance. The present study explored the influence of macroporous, open-pored structures of varying density and pore sizes that were obtained through non-isothermal laser fusion of polypropylene particles. By varying the number of consecutive exposure cycles, the coalescence of exposed particles is modified, allowing to adapt the density gradient perpendicular to the part surface while influencing the emerging pore size distribution, yielding mean porosities of 18.8% ± 4.64, and 13.9% ± 2.91, respectively. Comparable infrared spectroscopic surface characteristics prior and subsequent to sterilization were maintained regardless of the applied laser sintering process. The present study compared the influence of varying topographic properties on the viability and corresponding morphological characteristics of NIH/3T3 fibroblasts, chondrogenic ATDC-5 cells, and C2C12 myoblasts. While NIH/3T3 fibroblasts showed a comparable viability independent on the topography of manufactured specimens, chondrogenic ATDC-5 cells and C2C12 myoblasts displayed a significantly reduced viability on polypropylene specimens of reduced pore sizes and a reduced open-pored porosity of 13.9% ± 2.91. While C2C12 myoblasts were characterized by predominantly spherical shapes, a polygonal morphology of ATDC-5 cells could be observed, with both morphologies depicting a reduced viability on denser surface structures, associated with an adapted morphology expression on denser surfaces with reduced cell adhesion. These findings indicate the significance of the macro- and mesoscopic topography of polymer surfaces, potentially allowing for influencing the proliferation and the morphological structure of adhering cells. Moreover, the cell-specific interaction with process-related topographic characteristics can be identified as a crucial aspect for the development and biological optimization of additively manufactured, polymer-based implants. Conclusion Thermographic investigations have revealed that the formation of superficial porous layers is dependent on the residual temperature induced by the core layer exposure. This enables the process-induced control of emerging topologies. The vitro study demonstrates the potential of these surfaces to produce innovative applications in the areas of muscle regeneration, wound healing and cartilage repai

Process-Dependent Variations in the Proliferation of Myoblasts, Fibroblasts and Chondrocytes on Laser-Sintered Polypropylene - Detsch, Rainer; Schlicht, Samuel; Nawaz, Qaisar; Boccaccini, Aldo R.; Drummer, Dietmar (Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2025)
Additively manufactured polyolefins find broad applications in medical engineering, enabling the manufacturing of patient-specific geometries. For investigating the influence of processing conditions of laser sintered locally macroporous polypropylenesubstrates, the response of myoblasts, chondrocytes, and fibroblasts has been characterized in this study. An influence of the applied manufacturing parameters on the attachment and viability of the investigated cells is observed, showing the effect of the superficial pore topology on the attachment and the spreading of cells. The viability and attachment of fibroblasts and chondrocytescould be improved by reducing the thermal exposure during the processing step of the dense base part, associated with increasedsuperficial porosity and the corresponding increase of the surface area. The applied additive manufacturing process of macropo-rous structures influences emerging cell morphologies, leading to an extended morphological expression of chondrocytes and theovergrowth of small pores by fibroblasts. This indicates an improvement in superficial cell adhesion due to larger pores. These findings indicate the significance of the processing conditions in laser sintering of polypropylene on the cell response throughthe optimization of processing parameters and the attachment of an open-cell pore structur
Keywords: biopolymers; cell attachment; laser-sintering; macroporous polypropylene

PROCESSING AND ANTIBACTERIAL CHARACTERIZATION OF THERAPEUTIC ION-DOPED MESOPOROUS BIOACTIVE SILICATE GLASSES (MBGS) - Kaya, Seray; Cresswell, Mark; Boccaccini, Aldo R. (EUROMAT 2017 (European Congress and Exhibition on Advanced Materials and Processes), 2017)
The first bioactive silicate glass (BG) (45S5- 46.1SiO2, 24.4Na2O, 26.9CaO and 2.6P2O5 (mol%)) was invented by Larry Hench at the University of Florida in 1969 (Hench et al., 1971)and prepared by the melt-quenching method. After his invention there has been great interest to develop new BGs and in this perspective in 2004 Yan (Yan et al., 2004)produced the first MBG by combining sol-gel and surfactant templating methods. Imparting osteogenesis, antibacterial capacity, angiogenesis or cementogenesis properties to BGs can be achieved by incorporating biologically active ions (Hoppe et al., 2011). Doping MBGs with metallic ions has been also investigated (e.g. Wu and Chang, 2012). In this study, a new family of mesoporous silicate bioactive glasses doped with varying wt% of therapeutic antibacterial ions (Ag, Cu, Ce and Zn) has been synthesized via sol-gel technique in combination with a surfactant (Pluronic P123). After successful production of the MBGs, their resistance against E. coli and S. carnosus bacteria was investigated viathe disk diffusion test. Results have shown the increase in the percentage of doping ions, the inhibition zone for the growth of bacteria. It was observed that the largest inhibition zone was obtained with copper-doped MBGs. Zinc and cerium-doped MBGs are the least bacterial resistance. The implications of these results for designing novel MBGs with antibacterial capability.

Processing and bioactivity of 45S5 Bioglass®-graphene nanoplatelets composites - Porwal, Harshit; Grasso, Salvatore; Cordero Arias, Luis Eduardo; Li, Chunchun; Boccaccini, Aldo R.; Reece, Mike J. (Journal of Materials Science: Materials in Medicine, 2014)
Well dispersed 45S5 Bioglass® (BG)-graphene nanoplatelets (GNP) composites were prepared after optimising the processing conditions. Fully dense BG nanocomposites with GNP loading of 1, 3 and 5 vol% were consolidated using Spark plasma sintering (SPS). SPS avoided any structural damage of GNP as confirmed using Raman spectroscopy. GNP increased the viscosity of BG-GNP composites resulting in an increase in the sintering temperature by ∼50°C compared to pure BG. Electrical conductivity of BG-GNP composites increased with increasing concentration of GNP. The highest conductivity of 13 S/m was observed for BG-GNP (5 vol%) composite which is ∼9 orders of magnitude higher compared to pure BG. For both BG and BG-GNP composites, in vitro bioactivity testing was done using simulated body fluid for 1 and 3 days. XRD confirmed the formation of hydroxyapatite for BG and BG-GNP composites with cauliflower structures forming on top of the nano-composites surface. GNP increased the electrical conductivity of BG-GNP composites without affecting the bioactivity thus opening the possibility to fabricate bioactive and electrically conductive scaffolds for bone tissue engineering. © 2014 Springer Science+Business Media.

Processing and characterisation of alginate-based hydrogels for the application in 3-D Bio Platting - Detsch, Rainer; Zehnder, Tobias; Sarker, Bapi; Kaschta, Joachim; Schubert, Dirk W.; Boccaccini, Aldo R. (14th BIONANO-MATERIALS, 2013)

Processing and characterization of aligned electrospun gelatin/polycaprolactone nanofiber mats incorporating borate glass (13-93B3) microparticles - Ege, Duygu; Pourshahrestani, Sara; Iorio, Francesco; Reinfelder, Heike; de Ligny, Dominique; Boccaccini, Aldo R. (Biomedical Materials (Bristol), 2023)
Aligned biodegradable fibers incorporating bioactive glass particles are being highly investigated for tissue engineering applications. In this study, 5, 7 and 10 wt% melt-derived 1393B3 borate glass (BG) microparticles (average size: 3.15 µm) were incorporated in 83 wt% polycaprolactone (PCL) and 17 wt% gelatin (GEL) (83PCL/17GEL) solutions to produce aligned electrospun composite nanofiber mats. Addition of 5 wt% BG particles significantly increased the alignment of the nanofibers. However, further incorporation of BG particles led to reduced degree of alignment, likely due to an increase of viscosity. Mechanical tests indicated a tensile modulus and tensile strength of approximately 51 MPa and 3.4 MPa, respectively, for 5 wt% addition of 1393B3 BG microparticles, values considered suitable for soft tissue engineering applications. However, with the increasing amount of 1393B3 BG, the nanofiber mats became brittle. Contact angle was reduced after the addition of 5 wt% of 1393B3 BG particles from∼45° to∼39°. Cell culture studies with normal human dermal fibroblast (NHDF) cells indicated that 5 wt% 1393B3 BG incorporated nanofiber mats were cytocompatible whereas higher doping with 1393B3 BGs reduced biocompatibility. Overall, 5 wt% 1393B3 BG doped PCL/GEL nanofiber mats were aligned with high biocompatibility exhibiting desirable mechanical properties for soft tissue engineering, which indicates their potential for applications requiring aligned nanofibers, such as peripheral neural regeneration.
CRIS-Team Scopus Importer:2023-09-08
Keywords: bioactive glasses; borate glasses; electrospinning; nanofiber; peripheral nerve tissue regeneration; soft tissue engineering

Processing and Characterization of Mesoporous Bioactive Silicate Glasses Doped with Biologically Active Ions - Kaya, Seray; Cresswell, Mark; Boccaccini, Aldo R. (The International Workshop on Advanced Ceramics (IWAC 07), 2016)
There is a general research interest in upgrading the properties of mesoporous bioactive glasses (MBGs) by incorporating biologically active ions which can be released in a dose dependent manner [1-3]. By taking advantage of the silicate network of MBGs, small amounts of metallic ions can be substituted into the network which will have an impact on the biological response, including osteogenesis, antibacterial capacity, angiogenesis or cementogenesis [4-6]. In this study, a new family of mesoporous silicate bioactive glasses doped with several biologically active ions has been synthesized. The methodology to produce these glasses was the sol-gel technique in combination with surfactant-templating and evaporation-induced self-assembly (EISA) processes. After successful production of the mesoporous glasses, several techniques were performed to characterize them, in terms of their mesostructure, porosity, and degradation behavior in biological fluids. Finally, undoped and doped mesoporous silicate bioactive glasses were compared in terms of their antibacterial and bioactivity response and conclusions about the synergetic effect of doping with metallic ions were obtained, with a specific focus on their potential application in the treatment of critical bone defects.

Processing and cytocompatibility of Cu-doped and undoped fluoride-containing bioactive glasses - Nawaz, Qaisar; Blaeß, C.; Müller, R.; Boccaccini, Aldo R. (Open Ceramics, 2024)
Sintered or additive-manufactured bioactive glass (BG) scaffolds are highly interesting for bone replacement applications. However, crystallization often limits the high-temperature processability of bioactive glasses (BGs). Thus, the BG composition must combine high bioactivity and processability. In this study, three BGs with nominal molar (%) compositions 54.6SiO2-1.7P2O3-22.1CaO-6.0Na2O-7.9K2O-7.7MgO (13–93), 44.8SiO2-2.5P2O3-36.5CaO-6.6Na2O-6.6K2O-3.0CaF2 (F3) and 44.8SiO2-2.5P2O3-35.5CaO-6.6Na2O-6.6K2O-3.0CaF2-1.0CuO (F3–Cu) were investigated. The dissolution and ion release kinetics were investigated on milled glass powder and crystallized particles (500–600 μm). All glasses showed the precipitation of hydroxyapatite (HAp) crystals after 7 days of immersion in simulated body fluid. No significant differences in ion release from glass and crystalline samples were detected. The influence of surface roughness on cytocompatibility and growth of pre-osteoblast cells (MC3T3-E1) was investigated on sintered and polished BG pellets. Results showed that sintered BG pellets were cytocompatible, and cells were seen to be well attached and spread on the surface after 5 days of incubation. The results showed an inverse relation of cell viability with the surface roughness of pellets, and cells were seen to attach and spread along the direction of scratches.
CRIS-Team Scopus Importer:2024-04-12
Keywords: Bioactive glass; Crystallization; Cytocompatibility; Solubility; Surface roughness

Processing and strengthening of 58S bioactive glass-infiltrated titania scaffolds - Mesquita-Guimaraes, Joana; Leite, M. A.; Souza, J. C. M.; Henriques, Bruno; Silva, F. S.; Hotza, Dachamir; Boccaccini, Aldo R.; Fredel, M. C. (Journal of Biomedical Materials Research Part A, 2017)
Keywords: bioactive glass; hybrid scaffolds; mechanical properties; titanium dioxide; zeta potential

Processing of 45S5 Bioglass by lithography-based additive manufacturing - Tesavibul, Passakorn; Felzmann, Ruth; Gruber, Simon; Liska, Robert; Thompson, Ian; Boccaccini, Aldo R.; Stampfl, Juergen (Materials Letters, 2012)
Lithography-based Additive Manufacturing Technologies (AMTs) were used for fabricating cellular structures made of 45S5 Bioglass®. Using AMTs it is possible to design and fabricate cellular structures with a resolution of around 40 μm and wall thicknesses down to 200 μm. The presented process relies on selectively polymerizing a photosensitive, ceramic-filled resin with a dynamic mask. The dynamic mask is based on a digital mirror array which projects blue light (light emitting diodes with a wavelength of 460 nm) onto the resin. The mechanical properties of sintered bulk samples (biaxial strength) and cylindrical cellular structures (compressive strength) were determined. The biaxial strength of the manufactured samples was 40 MPa, and the compressive strength of the cellular structure was 0.33 MPa, which is slightly lower than the strength of porous Bioglass® structures made by the foam replica method. Lithography-based AMT offers an excellent alternative to existing bone implant and scaffold fabrication methods providing accurate control of 3D morphology and pore architecture. © 2012 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.proces
Keywords: Biomaterials; Biomimetic; Porous materials; Structural

Processing of porous glass ceramics from highly crystallisable industrial wastes - Chinnam, Rama Krishna Satish; Bernardo, Enrico; Will, Julia; Boccaccini, Aldo R. (Advances in Applied Ceramics, 2015)
This study was carried out to gain understanding about the sintering behaviour of highly crystallisable industrial waste derived silicate mixtures under direct heating and rapid cooling conditions. The materials used in this study were plasma vitrified air pollution control waste and rejected pharmaceutical borosilicate glass. Powder compacts sintered under direct heating conditions were highly porous; compacts with particle size <38 mu m reached a maximum density of 2.74 g cm(-3) at 850 degrees C, whereas compacts with particles of size <100 and <250 mu m reached maximum densities of 2.69 and 2.72 g cm(-3) at 875 and 900 degrees C respectively. Further increase in sintering temperature resulted in a rapid decrease in density of the glass ceramics. Image analysis results were used to link the sudden drop in density to the increase in volume of microsized pores formed in the samples during sintering. In particular, compacts made from <38 mu m particles sintered at 950 degrees C resulted in 65 vol.-% porosity with a pore size of similar to 20 mu m. Such materials can be used for sound and thermal insulation purposes.
Keywords: Porosity; Glass ceramics; Industrial waste; Silicates; Sintering; Recycling

Processing, physico-chemical characterisation and in vitro evaluation of silicon containing β-tricalcium phosphate ceramics - Detsch, Rainer; et al. (Materials Science and Engineering C, 2011)
For bone grafting applications, the elaboration of silicon containing beta-tricalcium phosphate (β-TCP) was studied. The synthesis was performed using a wet precipitation method according to the hypothetical theoretical formula Ca(PO)(SiO ). Two silicon loaded materials (0.46 wt.% and 0.95 wt.%) were investigated and compared to a pure β-TCP. The maturation time of the synthesis required in order to obtain β-TCP decreased with the amount of silicon. Only restrictive synthesis conditions allow preparing silicon containing β-TCP with controlled composition. To obtain dense ceramics, the sintering behaviour of the powders was evaluated. The addition of silicon slowed the densification process and decreased the grain size of the dense ceramics. Rietveld refinement may indicate a partial incorporation of silicon in the β-TCP lattice. X-ray photoelectron spectroscopy and transmission electron microscopy analyses revealed that the remaining silicon formed amorphous clusters of silicon rich phase. The in vitro biological behaviour was investigated with MC3T3-E1 osteoblast-like cells. After the addition of silicon, the ceramics remained cytocompatible, highlighting the high potential of silicon containing β-TCP as optimised bone graft material. © 2010 Elsevier B.V. All rights reserved.
Keywords: In vitro evaluation; Powder synthesis; Silicon; Sintering; Tricalcium phosphate

Processing Technologies for 3D Nanostructured Tissue Engineering Scaffolds - Meng, Decheng; Erol, Melek; Boccaccini, Aldo R. (Advanced Engineering Materials, 2010)
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.proces

Production of a novel poly(ɛ-caprolactone)-methylcellulose electrospun wound dressing by incorporating bioactive glass and Manuka honey - Schuhladen, Katharina; Vakamulla Raghu, Swathi Naidu; Liverani, Liliana; Neščáková, Zuzana; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2020)
Wound dressings produced by electrospinning exhibit a fibrous structure close to the one of the extracellular matrix of the skin. In this article, electrospinning was used to fabricate fiber mats based on the well-known biopolymers poly(ɛ-caprolactone) (PCL) and methylcellulose (MC) using benign solvents. The blend fiber mats were cross-linked using Manuka honey and additionally used as a biodegradable platform to deliver bioactive glass particles. It was hypothesized that a dual therapeutic effect can be achieved by combining Manuka honey and bioactive glass. Morphological and chemical examinations confirmed the successful production of submicrometric PCL-MC fiber mats containing Manuka honey and bioactive glass particles. The multifunctional fiber mats exhibited improved wettability and suitable mechanical properties (ultimate tensile strength of 3–5 MPa). By performing dissolution tests using simulated body fluid, the improved bioactivity of the fiber mats by the addition of bioactive glass was confirmed. Additionally, cell biology tests using human dermal fibroblasts and human keratinocytes-like HaCaT cells showed the potential of the fabricated composite fiber mats to be used as wound dressing, specially due to the ability to support wound closure influenced by the presence of bioactive glass. Moreover, based on the results of the antibacterial tests, it is apparent that an optimization of the electrospun fiber mats is required to develop suitable wound dressing for the treatment of infected wounds.
CRIS-Team Scopus Importer:2020-07-31
Keywords: bioactive glass; electrospinning; Manuka honey; methylcellulose; wound healing

Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues - Kourti, Ioanna; Rani, D. Amutha; Deegan, D.; Boccaccini, Aldo R.; Cheeseman, Christopher R. (Journal of Hazardous Materials, 2010)
Air pollution control (APC) residues are the hazardous waste produced from cleaning gaseous emissions at energy-from-waste (EfW) facilities processing municipal solid waste (MSW). APC residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium alumino-silicate glass. This research has investigated the optimisation and properties of geopolymers prepared from this glass. Work has shown that high strength geopolymers can be formed and that the NaOH concentration of the activating solution significantly affects the properties. The broad particle size distribution of the APC residue glass used in these experiments results in a microstructure that contains unreacted glass particles included within a geopolymer binder phase. The high calcium content of APC residues may cause the formation of some amorphous calcium silicate hydrate (C-S-H) gel. A mix prepared with S/L = 3.4, Si/Al = 2.6 and [NaOH] = 6 M in the activating solution, produced high strength geopolymers with compressive strengths of ∼130 MPa. This material had high density (2070 kg/m3) and low porosity. The research demonstrates for the first time that glass derived from DC plasma treatment of APC residues can be used to form high strength geopolymer-glass composites that have potential for use in a range of applications. © 2009 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.produc
Keywords: Energy; Geopolymers; Incineration; Plasma; Waste

Production of nepheline/quartz ceramics from geopolymer mortars - Kuenzel, C.; Grover, L. M.; Vandeperre, Luc; Boccaccini, Aldo R.; Cheeseman, C. R. (Journal of the European Ceramic Society, 2013)
This research has investigated the mechanical properties and microstructure of metakaolin derived geopolymer mortars containing 50% by weight of silica sand, after exposure to temperatures up to 1200°C. The compressive strength, porosity and microstructure of the geopolymer mortar samples were not significantly affected by temperatures up to 800°C. Nepheline (NaAlSiO 4) and carnegieite (NaAlSiO 4) form at 900°C in the geopolymer phase and after exposure to 1000°C the mortar samples were transformed into polycrystalline nepheline/quartz ceramics with relatively high compressive strength (∼275MPa) and high Vickers hardness (∼350 HV). Between 1000 and 1200°C the samples soften with gas evolution causing the formation of closed porosity that reduced sample density and limited the mechanical properties. © 2012 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.produc
Keywords: A. Sintering; C. Mechanical properties; Ceramic; Final microstructure; Geopolymer

Production of novel ceramic materials from coal fly ash and metal finishing wastes - Little, M. R.; Adell, V.; Boccaccini, Aldo R.; Cheeseman, C. R. (Resources Conservation and Recycling, 2008)
Fly ash from coal fired power stations is a potential raw material for the production of ceramic tiles, bricks and blocks. Previous work has demonstrated that the addition of metals can significantly alter fly ash sintering. Metal finishing produces problematic waste filter cakes and sludges that are increasingly difficult to dispose of to landfill. The objective of this research was to investigate the effect of selected metal finishing wastes on the properties of sintered fly ash. A 10 wt.% addition of dried metal finishing sludge obtained from the phosphate bath at a tri-cationic phosphating operation significantly reduced the sintering temperature for maximum density by approximately 75 °C. The addition of the phosphate bath sludge also reduced leaching of As, to the extent that fly ash ceramics containing this waste would be classified as inert. Potential industrial applications for these novel waste-derived ceramic materials are discussed. © 2008 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.produc
Keywords: Ceramics; Fly ash; Metal finishing wastes; Pressing; Sintering; Waste reuse

Production of pulverised fuel ash tiles using conventional ceramic production processes - Bou, E.; Quereda, M. F.; Lever, D.; Boccaccini, Aldo R.; Cheeseman, C. R. (Advances in Applied Ceramics, 2009)
The feasibility of manufacturing sintered ceramic tiles containing a high proportion of pulverised fuel ash (PFA) using conventional ceramic tile processing methods has been investigated at pilot plant scale. From earlier laboratory experiments, a composition containing 92.0 wt-%PFA, 5.0 wt-% sodium bentonite and 3.0 wt-% talc produced good quality small disc samples. The scale-up trials reported here used this same composition and involved deflocculant addition, wet milling, spray drying, pressing and firing, with the behaviour during each processing stage being characterised. Although there were no substantial technical problems associated with forming green tiles, the composition selected needed high levels of deflocculant and produced pressed samples with low green densities, resulting in high shrinkage during firing. The high dependence of shrinkage on temperature caused excessive tile distortion. In addition, sintered samples with less than 2% water absorption exhibited a bloating effect, resulting in poor surface quality. Possible solutions to the problems encountered during the pilot scale trials are considered and the potential commercial viability of high PFA content ceramic products is discussed. © 2009 Institute of Materials, Minerals and Mining Published by Maney on behalf of the Institute.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.produc
Keywords: Ceramics; Fly ash; Pulverised fuel ash; Reuse; Sintering; Waste

Production of sintered materials from air pollution control residues from waste incineration - Dimech, C.; Cheeseman, C. R.; Cook, S.; Simon, J.; Boccaccini, Aldo R. (Journal of Materials Science, 2008)
Air pollution control residues from waste incineration have been washed to remove excess chloride and other soluble salts and blended with combinations of soda lime glass and waste electrostatic precipitator dust containing boric oxide from the fibre-glass industry. Homogenous fine powder mixes have been pressed and sintered at temperatures between 900 and 1000 °C. The physical properties and microstuctural characteristics of the glass-ceramics formed have been assessed. The results show that it is possible to produce a dense glass-ceramic material containing wollastonite and gehlenite crystalline phases with a hardness of 4.5 GPa. The high density and hardness means that the glass-ceramic may have a potential use in high value construction products. © 2008 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.produc_9

Progress on Electrospun Composite Fibers Incorporating Bioactive Glass: An Overview - Ghorbani, Farnaz; Reiter, Theresa; Liverani, Liliana; Schubert, Dirk W.; Boccaccini, Aldo R.; Roether, Judith (Advanced Engineering Materials, 2023)
Electrospinning is a promising approach for the development of fibrous tissue engineering (TE) scaffolds suitable for hard and soft tissues. Apart from physicomechanical properties, electrospun fibers are required to incorporate bioactive cues to control cellular functions, including facilitating biomineralization and osteogenic differentiation in case of bone TE, as well as vascularization, to support successful tissue regeneration. In recent years, bioactive glass (BG) addition to electrospun biopolymer fibers has shown promising results in enhancing the properties of fibers, including the improvement of biological performance. In this article, a comprehensive overview of BG-containing electrospun polymer composite fibers is presented, identifying the parameters that affect the mechanical properties as well as the biological response in vivo and in vitro. Subsequently, the effects of BG addition on the properties of the scaffolds are discussed. Recent developments in the fields of bone regeneration, wound healing, and drug delivery using BG-containing electrospun fibrous scaffolds are described in detail. Essential aspects related to BG-polymer composite fibers for translational research in TE are highlighted for future research in this field.
CRIS-Team WoS Importer:2023-02-03

Propagation-Based Phase Contrast Computed Tomography as a Suitable Tool for the Characterization of Spatial 3D Cell Distribution in Biomaterials - Wieland, D. C.Florian; Krueger, Simone; Moosmann, Julian; Distler, Thomas; Weizel, Alina; Boccaccini, Aldo R.; Seitz, Hermann; Jonitz-Heincke, Anika; Bader, Rainer (Advanced Engineering Materials, 2021)
The 3D structural investigation of soft tissue samples under near physiological conditions is challenging as most established techniques require embedding, staining, or cutting samples. Such manipulations can induce artifacts or result in a tremendous workload by, e.g., the preparation of multiple 2D images to retrieve the volume information. A non-invasive technique allowing to image the soft tissue in a 3D fashion is propagation-based phase contrast computed tomography. We explore the methods' unique properties to assess the 3D distribution and size of human chondrocytes within collagen scaffolds in a liquid environment without embedding. To seek if the identification of differences in cell distribution is possible, we have seeded cartilage cells on collagen scaffolds that were unstimulated or stimulated by alternating electric fields for 7 days. Analysis of the 3D cell distributions reveals that the migration depth of the chondrocytes into the scaffold is nearly doubled along with the total number of cells due to the applied electric field. Further analysis shows no specific size distribution of the chondrogenic cells. Our results indicate that propagation-based phase contrast computed tomography is a suitable tool to determine the 3D distribution of cells within a biomaterial investigated under aqueous conditions.
CRIS-Team Scopus Importer:2021-04-30
Keywords: biomaterials; histology; multimodal analysis; phase contrast tomography

Properties of sintered glass-ceramics prepared from plasma vitrified air pollution control residues - Roether, Judith; Daniel, D. J.; Rani, D. Amutha; Deegan, D. E.; Cheeseman, Christopher R.; Boccaccini, Aldo R. (Journal of Hazardous Materials, 2010)
Air pollution control (APC) residues, obtained from a major UK energy from waste (EfW) plant, processing municipal solid waste, have been blended with silica and alumina and melted using DC plasma arc technology. The glass produced was crushed, milled, uni-axially pressed and sintered at temperatures between 750 and 1150 °C, and the glass-ceramics formed were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties assessed included Vickers's hardness, flexural strength, Young's modulus and thermal shock resistance. The optimum sintering temperature was found to be 950 °C. This produced a glass-ceramic with high density (∼2.58 g/cm3), minimum water absorption (∼2%) and relatively high mechanical strength (∼81 ± 4 MPa). Thermal shock testing showed that 950 °C sintered samples could withstand a 700 °C quench in water without micro-cracking. The research demonstrates that glass-ceramics can be readily formed from DC plasma treated APC residues and that these have comparable properties to marble and porcelain. This novel approach represents a technically and commercially viable treatment option for APC residues that allow the beneficial reuse of this problematic waste. © 2009 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.proper
Keywords: Air pollution control residues; Energy from waste; Glass-ceramics; Hazardous waste treatment; Plasma vitrification

Protective coatings for carbon bonded carbon fibre composites - Smeacetto, F.; Ferraris, M.; Saivo, M.; Ellacott, S. D.; Ahmed, A.; Rawlings, R. D.; Boccaccini, Aldo R. (Ceramics International, 2008)
Carbon bonded carbon fibre composites (CBCF) were modified by direct reaction with molten silicon in order to obtain a silicon carbide layer on the composite surface. Subsequently, the Si-infiltrated CBCF material was coated with a silica-based glass containing yttria and alumina by means of a slurry-dipping technique. On heat treatment the glass yielded a glass-ceramic layer thus giving a multi-layered oxidation and erosion protection system. The microstructural characterisation of the coating was conducted by standard microscopy techniques and by X-ray diffraction. The controlled crystallization of the glass-produced cristobalite, yttrium silicate (Y2Si2O7, keiviite, β-form) and mullite as main crystalline phases. These are excellent ceramic materials for oxidation and erosion protection of SiC-coated carbon-based composites since their coefficients of thermal expansion (CTE) closely match that of SiC. The possibility of healing (closure) of micro cracks by a thermal treatment at 1375 °C, thus exploiting the viscous flow of the residual glass in the glass-ceramic, was explored in order to extend the service life of the protection system. © 2007 Elsevier Ltd and Techna Group S.r.l.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.protec
Keywords: Carbon matrix composites; D. Glass ceramics; Oxidation protection; Slurry infiltration

Protein-adsorption and Ca-phosphate formation on chitosan-bioactive glass composite coatings - Wagener, Victoria; Boccaccini, Aldo R.; Virtanen, Sannakaisa (Applied Surface Science, 2017)
Keywords: Bioactive glass; Chitosan; EPD; Protein adsorption; ToF-SIMS; XPS calcium-phosphate precipitation

Protein adsorption on magnesium and its alloys: A review - Höhn, Sarah; Virtanen, Sannakaisa; Boccaccini, Aldo R. (Applied Surface Science, 2019)
Keywords: Corrosion; Adsorption; Magnesium; Interface; Proteins

Protein adsorption on sio2-cao bioactive glass nanoparticles with controllable ca content - Kapp, Martin; Li, Chunde; Xu, Zeqian; Boccaccini, Aldo R.; Zheng, Kai (Nanomaterials, 2021)
Bioactive glass nanoparticles (BGNs) are emerging multifunctional building blocks for various biomedical applications. In this study, the primary aim was to develop monodispersed bi-nary SiO2-CaO BGNs with controllable Ca content. We successfully synthesized such spherical BGNs (size 110 nm) using a modified Stöber method. Our results showed that the incorporated Ca did not significantly affect particle size, specific surface area, and structure of BGNs. Concentrations of CaO in BGN compositions ranging from 0 to 10 mol% could be obtained without the gap between actual and nominal compositions. For this type of BGNs (specific surface area 30 m2/g), the maximum concentration of incorporated CaO appeared to be 12 mol%. The influence of Ca content on protein adsorption was investigated using bovine serum albumin (BSA) and lysozyme as model proteins. The amount of adsorbed proteins increased over time at the early stage of adsorption (<2 h), regardless of glass composition and protein type. Further incubation of BGNs with protein-con-taining solutions seemed to induce a reduced amount of adsorbed proteins, which was more signif-icant in BGNs with higher Ca content. The results indicate that the Ca content in BGNs is related to their protein adsorption behavior.
CRIS-Team Scopus Importer:2021-03-05
Keywords: Bioactive glass nanoparticles; Calcium; Protein adsorption

Protein-Based Hydrogels: Promising Materials for Tissue Engineering - Davari, Niyousha; Bakhtiary, Negar; Khajehmohammadi, Mehran; Sarkari, Soulmaz; Tolabi, Hamidreza; Ghorbani, Farnaz; Ghalandari, Behafarid (Polymers, 2022)
The successful design of a hydrogel for tissue engineering requires a profound understanding of its constituents' structural and molecular properties, as well as the proper selection of components. If the engineered processes are in line with the procedures that natural materials undergo to achieve the best network structure necessary for the formation of the hydrogel with desired properties, the failure rate of tissue engineering projects will be significantly reduced. In this review, we examine the behavior of proteins as an essential and effective component of hydrogels, and describe the factors that can enhance the protein-based hydrogels' structure. Furthermore, we outline the fabrication route of protein-based hydrogels from protein microstructure and the selection of appropriate materials according to recent research to growth factors, crucial members of the protein family, and their delivery approaches. Finally, the unmet needs and current challenges in developing the ideal biomaterials for protein-based hydrogels are discussed, and emerging strategies in this area are highlighted.
CRIS-Team WoS Importer:2022-03-18

Protein interactions with bioactive glass surfaces: A review - Zheng, Kai; Kapp, Martin; Boccaccini, Aldo R. (Applied Materials Today, 2019)
Bioactive glasses (BGs) are an important class of biomaterials being proposed for several biomedical applications including bone/soft tissue regeneration, bone substitute materials, bioactive orthopedic coatings, wound healing, cancer treatment, and drug delivery. Adsorption of proteins onto bioactive glass (BG) surfaces is the initial interaction between BGs and the biological medium, e.g., blood plasma, interstitial fluids. Protein adsorption plays an essential role in determining biocompatibility, cell adhesion and proliferation as well as influencing a series of cellular pathways after cell-material contact. Understanding the adsorption of proteins on BGs is thus necessary for accelerating the development and applications of next-generation BG-based healthcare materials and devices. In this review, we comprehensively cover previous literature regarding protein adsorption on BG surfaces. The factors impacting protein adsorption on these bioreactive materials are summarized and discussed. In particular, the influence of BG surface properties (e.g., surface topography, composition) on protein adsorption is highlighted. The effects of adsorbed proteins on the surface properties of BGs, in terms of biological response, biomineralization (hydroxyapatite formation in contact with biological fluids), and BG dissolution, are also covered in this review. The paper discusses the methods suitable to analyze the protein adsorption process and to characterize possible changes in the structure of adsorbed proteins, and also presents approaches to control the protein adsorption phenomenon. A discussion on applications of protein adsorbed BGs is also included. The review also highlights the current challenges and uncertainties in this field and discusses future research directions.
CRIS-Team Scopus Importer:2019-06-07
Keywords: Applications; Bioreactive materials; Cellular response; Protein adsorption; Solid surfaces

Proving the role of boron in the structure of fly-ash/borosilicate glass based geopolymers - Taveri, Gianmarco; Toušek, Jaromír; Bernardo, Enrico; Toniolo, Nicoletta; Boccaccini, Aldo R.; Dlouhy⁠, Ivo (Materials Letters, 2017)
A spectroscopic investigation was carried out in order to determine the boron evolution into the structure of fly-ash based geopolymers, integrated with borosilicate glass coming from pharmaceutical waste. Fourier transformed infra-red (FTIR) spectroscopy was used to define the type of bonds after geopolymerization. Various solid-state nuclear magnetic resonance (MAS-NMR) measurements were instrumental to evaluate the extent of network formation in the structure and to compare the type of environments among the geopolymerization products and the source materials. ⁠11B NMR conducted firstly on a pure borosilicate glass sample and then on a geopolymeric sample evidenced a variation of the chemical shifts of the pattern, proving that boron oxide (B⁠2O⁠3) initially dissolved and then took part in polycondensation reactions. FTIR spectroscopy showed the characteristic peaks of a geopolymeric product, also proving that the effectiveness of the reaction was not affected by incorporation of boron.
Keywords: Fly-ash Borosilicate Geopolymerization Spectroscopy NMR FTIR

Pseudotachylyte in muscovite-bearing quartzite: Coseismic friction-induced melting and plastic deformation of quartz - Bestmann, Michel; Pennacchioni, Giorgio; Frank, Gerhard; Göken, Mathias; de Wall, Helga (Journal of Structural Geology, 2011)
Thin (0.5–2 mm thick) pseudotachylyte veins occur within muscovite-bearing ( 10% volume), amphibolite-facies quartzites of the Schneeberg Normal Fault Zone (Austroalpine, Southern Tyrol, Italy). Pseudotachylytes are associated with precursor localized plastic microshear zones (50–150 extgreekmm thick) developed sub-parallel to the host-rock foliation and with conjugate sets oriented at a high angle to the foliation. Such microshear zones are characterized by recrystallization to ultrafine-grained (1–2 extgreekmm grain size) mosaic aggregates of quartz showing a transition from a host-controlled to a random crystallographic preferred orientation towards the shear zone interior. Subsequent coseismic slip mainly exploited these microshear zones. Microstructural analysis provides evidence of extensive friction-induced melting of the muscovite-bearing quartzite, producing a bimodal melt composition. First, the host-rock muscovite was completely melted and subsequently crystallized, mainly as K-feldspar. Then, about 60% volume of the ultrafine-grained quartz underwent melting and crystallized as spherulitic rims (mostly consisting of quartz ± Ti ± Fe) around melt-corroded quartz clasts. The two melts show immiscibility structures in the major injection veins exploiting microshear zones at high angles to the quartzite foliation. In contrast, they were mechanically mixed during flow along the main fault veins.
WW1::896

Pulse electrodeposition and characterization of non-continuous, multi-element-doped hydroxyapatite bioceramic coatings - Furko, Monika; May, Zoltan; Havasi, Viktor; Konya, Zoltan; Grünewald, Alina; Detsch, Rainer; Boccaccini, Aldo R.; Balazsi, Csaba (Journal of Solid State Electrochemistry, 2017)
Keywords: Bioceramic layer; Biocompatibility; Corrosion; Hydroxyapatite; Implant materials

PVA-gelatine based hydrogel loaded with astaxanthin and mesoporous bioactive glass nanoparticles for wound healing - Hernandez Rivera, Gabriela; Valdez, Hugo A.; Arango Ospina, Marcela; Delgado, Juan Francisco; Aguilar-Rabiela, Arturo E.; Gorgojo, Juan Pablo; Zhang, Huijun; Beltrán, Ana M.; Boccaccini, Aldo R.; Sanchez, Mirna (Journal of Drug Delivery Science and Technology, 2024)
Astaxanthin (AST) is a potent antioxidant phytochemical used in wound healing with promising results in-vitro. However, AST incorporation into clinical practice still faces challenges related to the susceptibility of AST to instability. One of the most innovative solutions proposed is the encapsulation of AST into hydrogels. This study focuses on innovating the wound healing potential of AST-containing hydrogels by introducing silicate mesoporous bioactive glass nanoparticles (MBGNs). These nanoparticles release biologically active ions that accelerate cell proliferation and migration. The results showcase an innovative synergistic effect between 1 μg/mL of AST with 100 μg/mL of MBGNs, outperforming the individual proliferation effect of AST or MBGNs alone. Separately, these compounds were encapsulated in physical and chemical cross-linked hydrogel for the compound protection and delivery, finding that PVA-gelatine hydrogels are a suitable matrix for the delivery of AST and MBGNs. Physically crosslinked hydrogels showed particularly convenient characteristics for potential clinical implementation while maintaining the synergetic effect of AST and MBGNs. Although chemically crosslinked hydrogels exhibited suitable characteristics as a vehicle for AST in biological assays, cell proliferation was reduced by 57 %. The results of this research open avenues for exploring the development of new composite matrices for the co-delivery of phytochemicals and MBGNs for cutting-edge biomedical applications.
CRIS-Team Scopus Importer:2024-10-11
Keywords: Astaxanthin; Bioactive glass; Hydrogels; Wound healing

Quantifying migration and polarization of murine mesenchymal stem cells on different bone substitutes by confocal laser scanning microscopy - Detsch, Rainer; et al. (Journal of Cranio-Maxillofacial Surgery, 2010)
Introduction: Cell migration is preceded by cell polarization. The aim of the present study was to evaluate the impact of the geometry of different bone substitutes on cell morphology and chemical responses in vitro. Materials and methods: Cell polarization and migration were monitored temporally by using confocal laser scanning microscopy (CLSM) to follow green fluorescent protein (GFP) ± mesenchymal stem cells (MSCs) on anorganic cancellous bovine bone (Bio-Oss), β-tricalcium phosphate (β-TCP) (chronOS) and highly porous calcium phosphate ceramics (Friedrich-Baur-Research-Institute for Biomaterials, Germany). Differentiation GFP ± MSCs was observed using pro-angiogenic and pro-osteogenic biomarkers. Results: At the third day of culture polarized vs. non-polarized cellular sub-populations were clearly established. Biomaterials that showed more than 40% of polarized cells at the 3rd day of culture, subsequently showed an enhanced cell migration compared to biomaterials, where non-polarized cells predominated (p < 0.003). This trend continued untill the 7th day of culture (p < 0.003). The expression of vascular endothelial growth factor was enhanced in biomaterials where cell polarization predominated at the 7th day of culture (p = 0.001). Conclusions: This model opens an interesting approach to understand osteoconductivity at a cellular level. MSCs are promising in bone tissue engineering considering the strong angiogenic effect before differentiation occurs. © 2010 European Association for Cranio-Maxillo-Facial Surgery.
Keywords: bone substitutes; cell migration; cell polarity; confocal scanning laser microscopy; green fluorescent protein; mesenchymal stem cells

Quantitative evaluation of electrophoretic deposition kinetics of graphene oxide - Diba, Mani; Garcia-Gallastegui, Ainara; Klupp Taylor, Robin; Pishbin, Fatemeh; Ryan, Mary P.; Shaffer, Milo S. P.; Boccaccini, Aldo R. (Carbon, 2014)
The electrophoretic deposition (EPD) technique is an attractive approach for development of graphene and graphene oxide (GO) films for a variety of applications. However, in order to establish the influence of the EPD parameters on the properties of the deposited films, a deeper investigation of the fundamental GO-EPD kinetics is required. Previous studies have reported a simultaneous anodic reduction of GO flakes during EPD, complicating the kinetics and process control. Therefore, in this study, low voltages were used to prevent significant GO reduction during EPD, as confirmed by XPS and FTIR. Accordingly, the GO-EPD kinetics was established as a function of deposition time and voltage, accompanied by microscopic characterization of the deposited films. The experimental results show that the deposition follows a linear growth law, in good agreement with the predictions of Hamaker's law. Comparisons of optical absorbance and profilometry provide estimates of (reduced) GO deposition rate, extinction coefficient, and density. © 2013 Elsevier Ltd. All rights reserved.

Quantitative Macromolecular Modeling Assay of Biopolymer-Based Hydrogels - Abroug, Nada; Schöbel, Lisa; Boccaccini, Aldo R.; Seitz, Hermann (Gels, 2024)
The rubber elasticity theory has been lengthily applied to several polymeric hydrogel substances and upgraded from idealistic models to consider imperfections in the polymer network. The theory relies solely on hyperelastic material models in order to provide a description of the elastic polymer network. While this is also applicable to polymer gels, such hydrogels are rather characterized by their water content and visco-elastic mechanical properties. In this work, we applied rubber elasticity constitutive models through hyperelastic parameter identification of hydrogels based on their stress–strain response to compression. We further performed swelling experiments and determined the intrinsic properties, i.e., density, of the specimens and their components. Additionally, we estimated their equilibrium swelling and employed it in the swelling-equilibrium theory in order to determine the polymer–solvent interaction parameter of each hydrogel with regard to cross-linking. Our results show that the average mesh size obtained from the rubber elasticity theory can be regarded as a concentration-dependent characteristic length of the hydrogel’s network and couples the non-linear elastic response to the specimens’ inherent visco-elasticity through hysteresis as a quantifier of energy dissipation under large deformation.
CRIS-Team Scopus Importer:2024-12-06
Keywords: biopolymer network structure; bound water; rubber elasticity; swelling; visco-elasticity

Quaternary and pentanar mesoporous bioactive glass nanoparticles as novel nanocarriers for gallic acid: Characterisation, drug release and antibacterial activity - Damian-Buda, Andrada-Ioana; Nawaz, Qaisar; Ünalan, Irem; Beltrán, Ana M.; Boccaccini, Aldo R. (Ceramics International, 2023)
Mesoporous bioactive glass nanoparticles (MBGNs) have gained considerable attention as multifunctional platforms for simultaneously releasing ions and phytotherapeutic compounds. Thus, in the first part of this study, MBGNs based on the 53SiO2–4P2O5–20CaO–23Na2O (wt %) (S53P4) composition were synthesized by a microemulsion assisted sol-gel method. More precisely, P2O5 was substituted with B2O3 and Na2O with MgO and/or ZnO. For B containing MBGNs all ions were successfully incorporated into the borosilicate structure without inducing crystallisation. In contrast, for S53P4 a poorly crystalline hydroxyapatite phase was identified. All MBGNs had a typical spherical shape with an internal radial network of mesopores. Additionally, for S53P4 a second fraction of particles with a smaller size and compact core was observed. Secondly, the feasibility of MBGNs as nanocarriers for gallic acid (GA) was evaluated. All drug-loaded samples showed a similar in vitro release profile which can be divided into three main phases: burst release, slow release and sustained release. Among the different compositions, S53P4 exhibited the highest cumulative release, whereas B and Mg containing particles exhibited the opposite. The presence of Zn in the MBGN compositions improved their antibacterial effect against both E. coli and S. aureus. Moreover, it was shown that depending on the MBGNs’ composition, the antibacterial activity of GA loaded MBGNs can be enhanced. Thus, the results proved that MBGNs can be used as controlled drug delivery system and, by tailoring the composition, a synergistic antibacterial effect can be achieved, considering that GA and biologically active ions are simultaneously released.
CRIS-Team Scopus Importer:2023-07-21
Keywords: Antibacterial effect; Control release; Gallic acid; Mesoporous bioactive glass nanoparticles

Quaternary bioactive glass-derived powders presenting submicrometric particles and antimicrobial activity - Novak, Sara; Orives, Juliane Resges; Nalin, Marcelo; Ünalan, Irem; Boccaccini, Aldo R.; de Camargo, Emerson R. (Ceramics International, 2022)
The biomedical engineering advances in the last years have been rising demand for multifunctional biomaterials. Bioactive glass (BG) submicron particles are potential candidates for the formulation of composites with improved dispersion and homogeneity between the constituents. This work presents the preparation of SiO2–Na2O–CaO–P2O5 glass-derived powders composed of particles with homogenous shapes and sizes between 300 and 500 nm. Two types of synthesis were employed for the preparation of the BG powders, the melt-quenching method, and a citric acid-assisted sol-gel route at a low citric acid concentration (0.005 mol L−1). The morphology of the particles was achieved by a low-energy process using a ball mill. These powders were characterized for their structure and surface area and evaluated for in vitro mineralization and antibacterial behavior. X-ray diffraction (XRD) analysis revealed different crystalline silicate phases in the sol-gel-derived powder and confirmed the amorphous structure of the melt-quenching-derived one. The surface of the particles was covered by hydroxycarbonate-apatite (HCA) after five days in simulated body fluid (SBF). The antibacterial activity against Staphylococcus aureus was higher for the sol-gel-derived powder, showing inhibition >99% of the bacteria growth in 24 h for all concentrations studied. These BG-based powders present a set of characteristics useful for the formulation of multifunctional composites for orthopedic applications.
CRIS-Team Scopus Importer:2022-07-22
Keywords: Antimicrobial glass; Bioactive glass-ceramic particles; Ion release; Mineralization

Random and aligned electrospun poly(ε-caprolactone) (PCL)/poly(1,8-octanediol-co-citrate) (POC) fiber mats for cardiac tissue engineering using benign solvents - Vogt, Lena; Boccaccini, Aldo R. (European Polymer Journal, 2021)
Cardiac tissue engineering (CTE) is a rising field of research aiming to provide strategies to repair or regenerate damaged heart tissue after events like myocardial infarction. Here, poly(1,8-octanediol-co-citrate) (POC) has been blended with poly(ε-caprolactone) (PCL) and the blend polymer was electrospun using the benign solvents acetic acid and formic acid to develop cardiac patches for CTE. The fiber mats were thermally crosslinked under mild conditions. Random and aligned PCL/POC fiber mats were investigated with regard to their morphological and physico-chemical properties, their degradation behavior, and their cytocompatibility in vitro. Homogenous and defect-free fibrous structures with average fiber diameters of 0.61 and 1.11 µm were observed for 2:1 and 1:1 ratios of PCL/POC blends. The wettability as well as mechanical properties of the PCL/POC fiber mats were dependent on blend composition, crosslinking treatment, and fiber orientation. While the wettability of the fiber mats was in a suitable range, the mechanical properties even exceeded necessary values for CTE after 14 days of incubation in Dulbecco's phosphate buffered saline (DPBS). The post-crosslinking of the fiber mats also increased the degradation resistance resulting in less acidic leaching and more stable fibers after 28 days in DPBS. Cytocompatibility tests with C2C12 cells demonstrated an excellent cytocompatibility of PCL/POC blends with a PCL/POC ratio of 2:1. Based on the obtained data, PCL/POC fiber mats made from benign solvents showed promising properties for applications in CTE as cardiac patches and should be subjected to further research to elucidate their in vitro and in vivo potential.
CRIS-Team Scopus Importer:2021-10-08
Keywords: Benign solvents; Cardiac tissue engineering (CTE); Electrospinning; Poly(1; 8-octanediol-co-citrate) (POC); Poly(ε-caprolactone) (PCL)

Rational design of a triple-layered coaxial extruder system: In silico and in vitro evaluations directed toward optimizing cell viability - Silva, Christian; Cortés-Rodriguez, Carlos J.; Hazur, Jonas; Reakasame, Supachai; Boccaccini, Aldo R. (International Journal of Bioprinting, 2020)
Biofabrication is a rapidly evolving field whose main goal is the manufacturing of three-dimensional (3D) cell-laden constructs that closely mimic tissues and organs. Despite recent advances on materials and techniques directed toward the achievement of this goal, several aspects such as tissue vascularization and prolonged cell functionality are limiting bench-to-bedside translation. Extrusion-based 3D bioprinting has been devised as a promising biofabrication technology to overcome these limitations, due to its versatility and wide availability. Here, we report the development of a triple-layered coaxial nozzle for use in the biomanufacturing of vascular networks and vessels. The design of the coaxial nozzle was first optimized toward guaranteeing high cell viability upon extrusion. This was done with the aid of in silico evaluations and their subsequent experimental validation by investigating the bioprinting of an alginate-based bioink. Results confirmed that the values for pressure distribution predicted by in silico experiments resulted in cell viabilities above 70% and further demonstrated the effect of layer thickness and extrusion pressure on cell viability. Our work paves the way for the rational design of multi-layered coaxial extrusion systems to be used in biofabrication approaches to replicate the very complex structures found in native organs and tissues.
CRIS-Team Scopus Importer:2020-08-28
Keywords: Biomaterials; Coaxial nozzle; Three-dimensional bioprinting; Tissue-engineered vessels; Vascularized tissues

Ready-to-print alginate inks: The effect of different divalent cations on physico-chemical properties of 3D printable alginate hydrogels - Falcone, Giovanni; Schrüfer, Stefan; Kuth, Sonja; Mazzei, Pierluigi; De Pasquale, Salvatore; Del Gaudio, Pasquale; Aquino, Rita P.; Boccaccini, Aldo R.; Russo, Paola (Carbohydrate Polymer Technologies and Applications, 2024)
Studies about the use of different divalent cations to produce 3D printed scaffolds are almost limited to their application as secondary crosslinking agents after the printing of alginate. For this reason, this research aims to demonstrate the possibility to develop alginate hydrogel-inks for 3D-printing application, exploiting the ionotropic gelation in a preprint step, by paying attention to the role of divalent cations on hydrogel-inks properties. The investigation of transversal relaxation time highlighted differences among inks (barium-ink 90.04 ms, calcium-ink 84.33 ms, and zinc-ink 75.05 ms) suggesting a potential influence of different cations. If all the inks showed a shear thinning behaviour with similar flowability index (0.153±0.018), they were characterised by different consistency index (from 2420 to 574 Pa•s), extrudability and homogeneity, parameters that influence the printing setup. In fact, to reach the same flowability and thus low deviation in the layer width for all inks, a variation in printing pressure and speed was necessary. Overall, it can be deduced that alginate inks preparation following a preprint crosslinking approach could be a valid method to overcome the alginate printability issues underlining the possibility to select the crosslinking cation according to the technological properties wanted for the final matrix.
CRIS-Team Scopus Importer:2024-06-14
Keywords: 3D printing; Alginate; Hydrogel-inks; Ionic crosslinking

Recent advances on spinel-based protective coatings for solid oxide cell metallic interconnects produced by electrophoretic deposition - Zanchi, E.; Sabato, A. G.; Molin, S.; Cempura, G.; Boccaccini, Aldo R.; Smeacetto, F. (Materials Letters, 2021)
The application of ceramic protective coatings to the metallic interconnects in solid oxide cells (SOCs) is a viable and effective method to limit interconnect degradation issues. This featured letter provides a critical overview of the main outcomes of current research on the use of the electrophoretic deposition (EPD) technique to produce protective coatings for SOC metallic interconnects, specifically focusing on different approaches to stabilise spinel-based suspensions, as well as the possible sintering procedures. The protective properties of EPD coatings are reviewed and discussed in terms of oxidation kinetics and area specific resistance evaluation. (C) 2020 Elsevier B.V. All rights reserved.
CRIS-Team WoS Importer:2021-03-05

Recent developments in electrophoretic deposition (EPD) of antibacterial coatings for biomedical applications- A review - Hadzhieva, Zoya; Boccaccini, Aldo R. (Current Opinion in Biomedical Engineering, 2022)
Bacterial infections are one of the leading causes for long-term failure of medical implants, associated with hospitalization, costly revision surgeries, increased morbidity and even mortality. Electrophoretic deposition (EPD) appears as a suitable coating technology to confer antibacterial efficacy to implant surfaces without changing the properties of the constituent (or base) material. Typical antibacterial coatings by EPD rely on bactericidal (release-killing, contact-killing and stimuli responsive-killing) and bacteriostatic (anti-adhesive) approaches. The current review paper presents novel strategies to prevent bacterial infections by means of EPD focusing on relevant published studies in the last two years and provides a critical reflection on future prospects of EPD-based biomedical coatings.
CRIS-Team WoS Importer:2022-04-29

Recent progress in inorganic and composite coatings with bactericidal capability for orthopaedic applications - Simchi, Abdolreza; Tamjid, E.; Pishbin, F.; Boccaccini, Aldo R. (Nanomedicine, 2011)
This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some disadvantages. These disadvantages include limited chemical stability, local inflammatory reactions, uncontrolled drug-release kinetics, late thrombosis and restenosis. As a result, embedding of bioactive compounds and biomolecules within inorganic coatings (bioceramics, bioactive glasses) is attracting significant attention. Recently nanoceramics have attracted interest because surface nanostructuring allows for improved cellular adhesion, enhances osteoblast proliferation and differentiation, and increases biomineralization. Organic-inorganic composite coatings, which combine biopolymers and bioactive ceramics that mimick bone structure to induce biomineralization, with the addition of biomolecules, represent alternative systems and ideal materials for "smart" implants. In this review, emphasis is placed on materials and processing techniques developed to advance the therapeutic use of biomolecules-eluting coatings, based on nanostructured ceramics. One part of this report is dedicated to inorganic and composite coatings with antibacterial functionality. From the Clinical Editor: Inorganic and composite nanotechnology-based coating methods have recently been developed for orthopedic applications, with the main goal to provide bactericide and other enhanced properties, which may result in reduced need for pharmaceutical interventions and overall more cost effective orthopedic procedures. This review discusses key aspects of the above developments. © 2011 Elsevier Inc.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.recent
Keywords: Antimicrobial; Ceramics; Coatings; Composites; Drug-eluting implants; Nanostructures

Recovery of Gallium from Bauxite Residue Using Combined Oxalic Acid Leaching with Adsorption onto Zeolite HY - Ujaczki, Éva; Courtney, Ronan; Cusack, Patricia; Chinnam, Rama Krishna Satish; Clifford, Seamus; Curtin, Teresa; O’Donoghue, Lisa (Journal of Sustainable Metallurgy, 2019)
Bauxite residue, the byproduct of alumina production, may potentially be a valuable source of strategically important metals, e.g. Gallium. Ga is considered critical element for the EU. To ensure adequate supply of Ga for the future, secondary sources such as bauxite residue should be exploited with efficient extraction methods. Therefore, in this study, mineral acids (H2SO4, HCl, and HNO3) and an organic acid (H2C2O4—oxalic acid), were evaluated for their efficiencies to extract Ga from bauxite residue. Using H2C2O4, the highest Ga leaching efficiencies were achieved, compared to other acids. The achieved leaching experimental results were considered for the construction of a design of experiment (DOE) model to achieve optimal conditions for Ga extraction using H2C2O4. These values were validated by experiments which resulted in 94% accuracy. In the second part of the study, using pure Ga solution, the adsorption of Ga onto zeolite HY was studied. The effects of adsorbent dosage, temperature, and contact time on the adsorption of Ga from solution by zeolite HY were studied. The obtained adsorption experimental results were used to construct a DOE model to achieve optimal conditions for Ga adsorption on to zeolite HY. The DOE-achieved optimal conditions were evaluated by experiments in pure Ga solution, which resulted in an efficiency of 99.4 %. In the third stage, the bauxite residue was leached in H2C2O4 under the optimal DOE conditions which resulted in 71% efficiency; thus the resulting bauxite residue solution was subjected to adsorption using zeolite HY under the optimal DOE conditions achieved. The Ga adsorption onto the zeolite was only 16% compared to the Ga adsorption of 99.4 % under the pure Ga solution, thus, representing the influences of the other leachates in the solution, which are minimizing the Ga adsorption onto the zeolite HY and providing an opportunity for future studies on the different mechanisms involved.
CRIS-Team Scopus Importer:2019-06-21
Keywords: Adsorption; Bauxite residue; Critical raw materials; Design of experiments; Extraction; Oxalic acid; Zeolite

Recycling of pre-stabilized municipal waste incinerator fly ash and soda-lime glass into sintered glass-ceramics - Ponsot, Ines; Bernardo, Enrico; Bontempi, Elza; Depero, Laura; Detsch, Rainer; Chinnam, Rama Krishna Satish; Boccaccini, Aldo R. (Journal of Cleaner Production, 2015)
A recent method, based on the use of amorphous silica, allows for the inertization of MSWI fly ash, avoiding expensive vitrification. The present paper demonstrates that glass-ceramics, i.e the most established products from waste-derived glasses, are feasible by direct, inexpensive viscous flow sintering of pre-stabilized fly ash mixed with clay and recycled soda-lime glass. The sintering treatment did not compromise the chemical stabilization of fly ash, as confirmed by leaching test and by cell culture studies (with mouse embryonic fibroblasts used to assess possible cytotoxicity), applied on sintered glass-ceramics. Optimized glass-ceramic tiles, processed at 1050 °C for 30 min, not only featured attractive aesthetic appearance and low water absorption (<2%), but also exhibited a remarkable specific strength (∼3.6 MPa cm/g).
Keywords: Cytotoxicity; Glass ceramics; MSWI fly ash

Re-engineering Artificial Neoplastic Milieus: Taking Lessons from Mechano- and Topobiology - Leal-Egaña, Aldo; Balland, Martial; Boccaccini, Aldo R. (Trends in Biotechnology, 2019)
Traditionally, cancer-like scaffolds have been developed with tissue regeneration in mind and therefore designed to mimic the regenerative environment of otherwise healthy tissues. However, the tumoral niche exhibits specific biophysical cues far from being ‘cell friendly’, suggesting that a different approach should be taken to design these artificial neoplastic niches. From bare 2D surfaces to 3D and 1D microstructured platforms, this opinion article focuses on evolving approaches used to mimic in vitro the neoplastic niche, discussing why this pathology cannot be assessed with tissue engineering (TE) approaches (i.e., using scaffolds facilitating cell growth, migration, and matrix degradation in the absence of diffusional restrictions, among others), and suggests how to improve them with recent lessons learned from mechanobiology and topobiology.
CRIS-Team Scopus Importer:2019-10-15
Keywords: artificial neoplastic architecture; biomaterials for cancer research; cancer-like scaffolds; mechanobiology; topobiology; tumor-like scaffold

Reepithelialization in focus: Non-invasive monitoring of epidermal wound healing in vitro - Kiesewetter, Lisa; Littau, Laura; Walles, Heike; Boccaccini, Aldo R.; Groeber-Becker, Florian (Biosensors and Bioelectronics, 2019)
Up to today, in vivo studies are the gold standard for testing of new therapeutics for cutaneous wound healing. Alternative in vitro studies are mostly limited to two-dimensional cell cultures and thus only poorly reflect the complex physiological wound situation. Here we present a new three-dimensional wound model based on a reconstructed human epidermis (RHE). We introduce impedance spectroscopy as a time-resolved test method to determine the efficacy of wound healing non-destructively by focusing on the barrier function of the RHE as a main feature of intact skin. We assessed the skin barrier quantitatively and qualitatively by calculating the transepithelial electrical resistance (TEER), by fitting an equivalent circuit and by analyzing the single characteristic frequency. Upon wounding using a 2 mm biopsy punch, the impedance dropped significantly to 3.5% of the initial value. Impedance spectroscopy thereby proved to be a sensitive tool to distinguish between wounds of different sizes. The glucose and lactate concentration in the medium revealed an acute stress reaction of the wounded RHE (wRHE) in the first days after wounding. During monitoring of reepithelialization over fourteen days, the barrier fully recovered. Microscopy and histology images correlate well with these findings, revealing an active wound closure mostly completed by day seven after wounding. These wounded epidermal models can now be applied in therapeutic screenings and with the help of rapid screening by impedance spectroscopy, expensive and time-consuming imaging and histological methods as well as the use of animal models can be reduced.
CRIS-Team Scopus Importer:2019-08-16
Keywords: Epidermal wound healing; Impedance spectroscopy; Reconstructed human epidermis; Reepithelialization; Transepithelial electrical resistance

REEPITHELIALIZATION IN FOCUS: RAPID SCREENING OF WOUND CLOSURE USING ORGANOTYPIC SKIN MODELS - Kiesewetter, Lisa; Littau, Laura; Boccaccini, Aldo R.; Walles, Heike; Groeber-Becker, Florian (WOUND REPAIR AND REGENERATION, 2019)
CRIS-Team WoS Importer:2019-04-18

Regenerating bone with bioactive glass scaffolds: A review of in vivo studies in bone defect models - El-Rashidy, Aiah A.; Roether, Judith; Harhaus, Leila; Kneser, Ulrich; Boccaccini, Aldo R. (Acta Biomaterialia, 2017)
Keywords: 3D scaffolds; Animal model; Bioactive glass; Bone defects; Bone regeneration; In vivo

Regenerative Medicine and Tissue Engineering: How Far Are We? - Horch, Raymund E.; Boccaccini, Aldo R.; Arkudas, Andreas (Journal of Tissue Science & Engineering, 2013)

Regional Chitosan and Melaleuca armillaris Essential Oil with Mesoporous Glass Particles for Enhancing Bioactive and Antibacterial Behaviour of Ti6Al4V Implants - Buldain, Daniel; Diaz, Florencia; Ünalan, Irem; Mestorino, Nora; Boccaccini, Aldo R.; Ballarre, Josefina (Arabian Journal for Science and Engineering, 2025)
Metal implants have long been studied and used for applications related to bone tissue engineering, thanks to their outstanding mechanical properties and appropriate biocompatibility. However, due to their lack of bioactivity, many implants struggle with osteointegration and attachment, and can be vulnerable to the development of infections. In this work, we have developed a composite coating via electrophoretic deposition which is both bioactive and antibacterial. We have loaded a combination of Melaleuca armillaris essential oil and gentamicin into mesoporous bioactive glass particles, and incorporated the nanoparticles into a chitosan solution electrophoretically deposited onto the titanium substrate. This coating significantly improves the antibacterial activity against both gram-positive and negative strains of bacteria compared to the bare substrate. The coating is biocompatible, as MG63 cells seeded on the coated materials exhibit their typical spindle-like morphology and can grow into a smooth layer on the surface after 7 days.
CRIS-Team Scopus Importer:2025-05-30
Keywords: Antibacterial effect; Bone regeneration; Chitosan; Electrophoretic deposition; Essential oils; Gentamicin; Mesoporous bioactive particles

Reinforced Hyaluronic Acid-Based Matrices Promote 3D Neuronal Network Formation - Janzen, Dieter; Bakirci, Ezgi; Faber, Jessica; Mier, Mateo Andrade; Hauptstein, Julia; Pal, Arindam; Forster, Leonard; Hazur, Jonas; Boccaccini, Aldo R.; Detsch, Rainer; Tessmar, Joerg; Budday, Silvia; et al. (Advanced Healthcare Materials, 2022)
3D neuronal cultures attempt to better replicate the in vivo environment to study neurological/neurodegenerative diseases compared to 2D models. A challenge to establish 3D neuron culture models is the low elastic modulus (30-500 Pa) of the native brain. Here, an ultra-soft matrix based on thiolated hyaluronic acid (HA-SH) reinforced with a microfiber frame is formulated and used. Hyaluronic acid represents an essential component of the brain extracellular matrix (ECM). Box-shaped frames with a microfiber spacing of 200 mu m composed of 10-layers of poly(e-caprolactone) (PCL) microfibers (9.7 +/- 0.2 mu m) made via melt electrowriting (MEW) are used to reinforce the HA-SH matrix which has an elastic modulus of 95 Pa. The neuronal viability is low in pure HA-SH matrix, however, when astrocytes are pre-seeded below this reinforced construct, they significantly support neuronal survival, network formation quantified by neurite length, and neuronal firing shown by Ca2+ imaging. The astrocyte-seeded HA-SH matrix is able to match the neuronal viability to the level of Matrigel, a gold standard matrix for neuronal culture for over two decades. Thus, this 3D MEW frame reinforced HA-SH composite with neurons and astrocytes constitutes a reliable and reproducible system to further study brain diseases.
CRIS-Team WoS Importer:2022-09-09

Reinforcement of calcium phosphate cement with multi-walled carbon nanotubes and bovine serum albumin for injectable bone substitute applications - Chew, Kean-Khoon; Low, Kah-Ling; Zein, Sharif Hussein Sharif; Mcphail, David S.; Gerhardt, Lutz-Christian; Roether, Judith A.; Boccaccini, Aldo R. (Journal of the Mechanical Behavior of Biomedical Materials, 2011)
This paper presents the development of novel alternative injectable calcium phosphate cement (CPC) composites for orthopaedic applications. The new CPC composites comprise β-tri-calcium phosphate (β-TCP) and di-calcium phosphate anhydrous (DCPA) mixed with bovine serum albumin (BSA) and incorporated with multi-walled carbon nanotubes (MWCNTs) or functionalized MWCNTs (MWCNTs-OH and MWCNTs-COOH). Scanning electron microscopy (SEM), compressive strength tests, injectability tests, Fourier transform infrared spectroscopy and X-ray diffraction were used to evaluate the properties of the final products. Compressive strength tests and SEM observations demonstrated particularly that the concomitant admixture of BSA and MWCNT improved the mechanical properties, resulting in stronger CPC composites. The presence of MWCNTs and BSA influenced the morphology of the hydroxyapatite (HA) crystals in the CPC matrix. BSA was found to act as a promoter of HA growth when bounded to the surface of CPC grains. MWCNT-OH-containing composites exhibited the highest compressive strengths (16.3 MPa), being in the range of values for trabecular bone (2-12 MPa). © 2010 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.reinfo
Keywords: Bovine serum albumin (BSA); Calcium phosphate cement (CPC); Carbon nanotubes (CNTs); Compressive strength; Injectability

Reinforcing Tissue-Engineered Cartilage: Nanofibrillated Cellulose Enhances Mechanical Properties of Alginate Dialdehyde–Gelatin Hydrogel - Chayanun, Slila; Ahmadi Soufivand, Anahita; Faber, Jessica; Budday, Silvia; Lohwongwatana, Boonrat; Boccaccini, Aldo R. (Advanced Engineering Materials, 2023)
Cartilage tissue engineering offers a promising option for treating osteochondral defects. Alginate dialdehyde–gelatin (ADA–GEL) hydrogel has been explored as promising material for soft tissue scaffolds; however, its low stiffness has posed a constraint to load bearing applications. Herein, this limitation is addressed by introducing nanofibrillated cellulose (NFC) into the ADA–GEL matrix. The effect of NFC on the physicochemical properties of hydrogels is evaluated. Fourier transform infrared spectra demonstrate no chemical interaction between NFC and ADA–GEL, while scanning electron microscopy pictures reveal NFC fibers embedded in the hydrogel matrix, thus confirming the fiber-reinforced composite hypothesis. NFC-reinforced ADA–GEL (AG-N) composite hydrogels exhibit increased stiffness, with a maximum compressive effective modulus of 19.6 ± 3.0 kPa at 25% w/w NFC content. ATDC5 cell viability and proliferation as well as chondrogenic differentiation are assessed using immunohistochemical staining for sulfated glycosaminoglycans and collagen type II. A possible application of AG-N hydrogels as an osteochondral plug is also proposed, with polyetheretherketone as the subchondral bone anchor part. The mechanical properties of the resulting osteochondral device highlight its potential as a promising biomaterial for treatment of osteochondral defects. These findings provide valuable insights into the development of AG-N hydrogels for load-bearing tissue engineering applications.
CRIS-Team Scopus Importer:2023-09-22
Keywords: alginate; alginate dialdehyde–gelatin; cartilage tissue engineering; nanofibrillated cellulose; osteochondral plugs

Relation between chemical composition, morphology, and microstructure of poly(ether ether ketone)/reduced graphene oxide nanocomposite coatings obtained by electrophoretic deposition - González Castillo, Eduin Ivan; Žitňan, Michal; Torres, Yadir; Shuttleworth, Peter S.; Galusek, Dušan; Ellis, Gary; Boccaccini, Aldo R. (Journal of Materials Science, 2022)
The effect of the chemical composition on the morphology and microstructure of poly(ether ether ketone) (PEEK)/reduced graphene oxide (RGO) nanocomposite coatings is analyzed. RGO induced three main morphological features in the nanocomposites: (i) a large-scale co-continuous morphology related to nanosheets whose basal planes were mainly aligned with the coating surface, (ii) a dendritic morphology of PEEK domains, and (iii) irregular domains related to the deposition of PEEK particles wrapped by the nanosheets. The development of these morphological features was influenced by the RGO content, allowing the modification of the surface roughness. RGO also induced changes in the melting and non-isothermal crystallization of the polymeric matrix and promoted transcrystallinity in PEEK that, in turn, was a key factor in the development of the final microstructure. In addition, polymer chain mobility was observed to be hindered at high nanofiller concentrations, increasing the glass transition temperature, and diminishing the recrystallization of the polymeric matrix.
CRIS-Team Scopus Importer:2022-03-11

Reply to the comment to: Bioactive layers based on black glasses on titanium substrates - 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)
CRIS-Team Scopus Importer:2022-08-05
Keywords: bioceramics; biocompatibility; coatings; silicon oxycarbide; sol-gel

Response of 45S5 Bioglass® foams to tensile loading - Rehorek, L.; Chlup, Zdenek; Meng, D.; Yunos, D. M.; Boccaccini, Aldo R.; Dlouhy, Ivo (Ceramics International, 2013)
The tensile strength test of highly porous ceramic foams has been developed and first results have been obtained on bioactive glass foams. The tested material was a 45S5 Bioglass® derived foam-like scaffold intended for use in bone tissue engineering which was manufactured by Bioglass® slurry coating of polyurethane foam and subsequent sintering. The Bioglass® foam structure was investigated in two states: uncoated (as fabricated) and with a PDLLA polymer coating. The tensile testing procedure is based on fixation of the foam into aluminium pots by a suitable adhesive. Tensile test samples having cross-section of 10×10 mm2 and a length of 30 mm were used for the experiments. Basic fractographic analysis was applied to get relevant information about specimens' behaviour during tensile loading. In Bioglass® based scaffolds, the presence of PDLLA coating led to a significant increase of the fracture strength, which is attributed to the interaction of the polymer phase with propagating cracks, e.g. enabling a crack bridging mechanism to take place. © 2013 Elsevier Ltd and Techna Group S.r.l.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.respon
Keywords: 45S5 Bioglass®; Foams; Open porosity; Scaffolds; Tensile strength

Reticulated bioactive scaffolds with improved textural properties for bone tissue engineering: Nanostructured surfaces and porosity - Ramiro-Gutiérrez, M. Lourdes; Will, Julia; Boccaccini, Aldo R.; Díaz-Cuenca, Aránzazu (Journal of Biomedical Materials Research Part A, 2013)
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.reticu

Review. Functional glasses and glass-ceramics derived from iron rich waste and combination of industrial residues - Chinnam, Rama Krishna Satish; Francis, A. A.; Will, Julia; Bernardo, Enrico; Boccaccini, Aldo R. (Journal of Non-Crystalline Solids, 2013)
Wastes from industrial processes and energy generation facilities pose environmental and health issues. Diversion of waste from landfill to favour reuse or recycling options and towards the fabrication of marketable products is of high economic and ecologic interest. Moreover safe recycling of industrial wastes is necessary and even vital to our society because of the increasing volume being generated. Glasses and glass-ceramics attract particular interest in waste recycling concepts. Novel and/or improved glass-based products from wastes should meet a variety of demands, among which the functional requirements are paramount. The investigations reviewed in this paper focusing on iron rich waste materials demonstrate the potential of turning these silicate based wastes into functional glass-based products. By properly selecting iron oxide containing residues and processing parameters, functional glass-based products with suitable catalytic activity, magnetic, optical and electrical properties can be obtained. The possibility of fabricating highly porous materials using different types of wastes for sound and thermal insulating as well as catalytic support applications is also discussed based on literature results. Thus, porosity can be considered to achieve particular properties in waste derived products. © 2012 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.review
Keywords: Functional properties; Glass-ceramics; Porous materials; Silicate waste

Review: Silicon oxycarbide based materials for biomedical applications - Arango Ospina, Marcela; Xie, Fangtong; Gonzalo-Juan, Isabel; Riedel, Ralf; Ionescu, Emanuel; Boccaccini, Aldo R. (Applied Materials Today, 2019)
Silicon oxycarbide (SiOC) based materials are of interest due to their unique properties, including high-temperature resistance, mechanical strength, chemical durability and corrosion resistance. The versatility of the silicon oxycarbide chemistry allows the modification of properties for different fields. In the last decade, attention has been paid to the potential use of SiOC materials in biomedical applications. Surface functionalization of SiOC is a promising approach to create efficient and controllable drug delivery systems with adequate molecule adsorption and release kinetics. The analysis of the literature reveals that silicon oxycarbides have also potential applications as protective biocompatible coatings, for example in blood-contact devices. Additionally, by incorporating metallic ions (i.e. Ca2+, Mg2+, Ag+) in the material network structure, promising antibacterial properties and bioactive behavior have been observed despite the high network connectivity values compared to silicate bioactive glasses. This review covers studies which have reported the use of silicon oxycarbide based materials for biomedical applications. Advances in the evaluation of biocompatibility, bioactivity, surface functionalization and antibacterial effects are discussed in detail, highlighting advantages and limitations of SiOC systems in the biomedical field.
CRIS-Team Scopus Importer:2019-11-05
Keywords: Bioactive glass; Biocompatibility; Coating; Cytotoxicity; Polymer-derived ceramic; Silicon oxycarbide

Rheological examination and 3D bioprinting of pre-gelled alginate hydrogels - Hazur, Jonas; Kaschta, Joachim; Bednarzig, Vera; Boccaccini, Aldo R.; Schubert, Dirk W.; Detsch, Rainer (Nordic Polymer Days 2018, 2018)
lginate hydrogels are from special interest in wound healing, drug delivery and tissue engineering applications, due to their biocompatibility and similarity to the extracellular matrices in tissues [1]. In this project, bioprinting of pre-crosslinked medical grade alginate gels via an internal gelation method using D-(+)-Gluconic acid-lactone in combination with CaCO3 was implemented and the rheological characteristics of the gels were examined. By parameter optimization, it was possible to print 3D porous structures with a height of 5 mm and a pore size of 1.1 mm with those gels. Surprisingly, the stirring process during cross-linking turned out to play a major role for the absolute value of complex viscosity (|η*|), as well as for the homogeneity of the gels. A significant increase of |η*| as well as of the storage modulus was obtained, when the gels were not stirred, leading to gels without viscous flow and therefore to less defined printed structures. Apart from that, the temperature during pre-crosslinking plays an important role on the homogeneity. At lower temperatures than room temperature, the gels showed a more uniform gelation process, compared to those at 20 °C. Furthermore, the concentration and temperature dependence of the alginate solutions were rheologically characterized. The shear dependent viscosities were superposable for both temperature and concentration and appropriate fitting functions in the investigated regions were derive

Robust graphene membranes in a silicon carbide frame - Waldmann, Daniel; Butz, Benjamin; Bauer, Sebastian; Englert, Jan; Jobst, Johannes; Ullmann, Konrad; Fromm, Felix; Ammon, Maximilian Michael; Enzelberger-Heim, Michael; Hirsch, Andreas; Maier, Sabine; Schmuki, Patrik; et al. (ACS nano, 2013)
We present a fabrication process for freely suspended membranes consisting of bi- and trilayer graphene grown on silicon carbide. The procedure, involving photoelectrochemical etching, enables the simultaneous fabrication of hundreds of arbitrarily shaped membranes with an area up to 500 μm(2) and a yield of around 90%. Micro-Raman and atomic force microscopy measurements confirm that the graphene layer withstands the electrochemical etching and show that the membranes are virtually unstrained. The process delivers membranes with a cleanliness suited for high-resolution transmission electron microscopy (HRTEM) at atomic scale. The membrane, and its frame, is very robust with respect to thermal cycling above 1000 °C as well as harsh acidic or alkaline treatment.

Role of ZnO additions on the β/α phase relation in TCP based materials: Phase stability, properties, dissolution and biological response - Carbajal, L.; Serena, S.; Caballero, A.; Sainz, M. A.; Detsch, Rainer; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2014)
Guided by the need to manufacture smart biomaterials, capable to replace and regenerate the mineral component of the bone, with optimized mechanical performance and bioresoption rate under physiological conditions, modified synthetic Zinc doped monophasic and/or biphasic β/α-tricalcium phosphate, Znc-Ca3-x(PO4)2 (Zn-TCP), dense bioceramics with different phase proportions and microstructures were synthesized by solid state sintering process.The compositions studied, ranging from 0.125 to 1.000wt% ZnO were formulated in the Ca3(PO4)2-Zn3(PO4)2 subsystem of the ternary ZnO-CaO-P2O5 system. The design and control of compositions and processing conditions, enabled to fulfill the requirement in which Zn2+ was incorporated in solid solution in the TCP structure. Consequently, biomaterials with controlled porosity, density, phase proportion and microstructural distribution of α/β-TCP polymorphs were developed.The effect of ZnO content on the final properties was discussed and an improvement in relation to pure TCP samples was obtained. The influence of the surface physico-chemical characteristics on the mechanical performance and "in vitro" solubility in SBF was also studied. In addition "in vitro" biocompatibility was evaluated using MG-63 human osteoblast cells, obtaining synthetic Zn-TCP based biomaterials with improved cell-material interaction. © 2013 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2014.tech.IW.LM.roleof
Keywords: Bioactivity; Biological response; Mechanical properties; Raman spectroscopy; Tricalcium phosphate; ZnO

Scaffold-Mediated Immunoengineering as Innovative Strategy for Tendon Regeneration - Russo, Valentina; El Khatib, Mohammad; Prencipe, Giuseppe; Cervero-Varona, Adrian; Citeroni, Maria Rita; Mauro, Annunziata; Berardinelli, Paolo; Faydaver, Melisa; Haidar-Montes, Arlette A.; Turriani, Maura; Di Giacinto, Oriana; Raspa, Marcello; et al. (Cells, 2022)
Tendon injuries are at the frontier of innovative approaches to public health concerns and sectoral policy objectives. Indeed, these injuries remain difficult to manage due to tendon's poor healing ability ascribable to a hypo-cellularity and low vascularity, leading to the formation of a fibrotic tissue affecting its functionality. Tissue engineering represents a promising solution for the regeneration of damaged tendons with the aim to stimulate tissue regeneration or to produce functional implantable biomaterials. However, any technological advancement must take into consideration the role of the immune system in tissue regeneration and the potential of biomaterial scaffolds to control the immune signaling, creating a pro-regenerative environment. In this context, immunoengineering has emerged as a new discipline, developing innovative strategies for tendon injuries. It aims at designing scaffolds, in combination with engineered bioactive molecules and/or stem cells, able to modulate the interaction between the transplanted biomaterial-scaffold and the host tissue allowing a pro-regenerative immune response, therefore hindering fibrosis occurrence at the injury site and guiding tendon regeneration. Thus, this review is aimed at giving an overview on the role exerted from different tissue engineering actors in leading immunoregeneration by crosstalking with stem and immune cells to generate new paradigms in designing regenerative medicine approaches for tendon injuries.
CRIS-Team WoS Importer:2022-02-04

Scaffolds for vascularized bone regeneration: Advances and challenges - Boccaccini, Aldo R.; Kneser, Ulrich; Arkudas, Andreas (Expert Review of Medical Devices, 2012)

Scavenging of bacteria or bacterial products by magnetic particles functionalized with a broad-spectrum pathogen recognition receptor motif offers diagnostic and therapeutic applications - Friedrich, Bernhard; Lyer, Stefan; Janko, Christina; Unterweger, Harald; Brox, Regine; Cunningham, Sarah; Dutz, Silvio; Taccardi, Nicola; Bikker, Floris J.; Hurle, Katrin; Sebald, Heidi; Lenz, Malte; et al. (Acta Biomaterialia, 2022)
Sepsis is a dysregulated host response of severe bloodstream infections, and given its frequency of occurrence and high mortality rate, therapeutic improvements are imperative. A reliable biomimetic strategy for the targeting and separation of bacterial pathogens in bloodstream infections involves the use of the broad-spectrum binding motif of human GP-340, a pattern-recognition receptor of the scavenger receptor cysteine rich (SRCR) superfamily that is expressed on epithelial surfaces but not found in blood. Here we show that these peptides, when conjugated to superparamagnetic iron oxide nanoparticles (SPIONs), can separate various bacterial endotoxins and intact microbes (E. coli, S. aureus, P. aeruginosa and S. marcescens) with high efficiency, especially at low and thus clinically relevant concentrations. This is accompanied by a subsequent strong depletion in cytokine release (TNF, IL-6, IL-1β, Il-10 and IFN-γ), which could have a direct therapeutic impact since escalating immune responses complicates severe bloodstream infections and sepsis courses. SPIONs are coated with aminoalkylsilane and capture peptides are orthogonally ligated to this surface. The particles behave fully cyto- and hemocompatible and do not interfere with host structures. Thus, this approach additionally aims to dramatically reduce diagnostic times for patients with suspected bloodstream infections and accelerate targeted antibiotic therapy. Statement of significance: Sepsis is often associated with excessive release of cytokines. This aspect and slow diagnostic procedures are the major therapeutic obstacles. The use of magnetic particles conjugated with small peptides derived from the binding motif of a broad-spectrum mucosal pathogen recognition protein GP-340 provides a highly efficient scavenging platform. These peptides are not found in blood and therefore are not subject to inhibitory mechanisms like in other concepts (mannose binding lectine, aptamers, antibodies). In this work, data are shown on the broad bacterial binding spectrum, highly efficient toxin depletion, which directly reduces the release of cytokines. Host cells are not affected and antibiotics not adsorbed. The particle bound microbes can be recultured without restriction and thus be used directly for diagnostics.
CRIS-Team Scopus Importer:2022-03-11
Keywords: GP-340; Magnetic nanoparticles; Pathogen binding; Sepsis; SRCR domain

Screening of Azo-Dye-Degrading Bacteria from Textile Industry Wastewater-Activated Sludge - de Vasconcelos, Grazielly Maria Didier; Della-Flora, Isabela; Kelbert, Maikon; de Andrade, Lidiane Maria; Oliveira, Débora de; Guelli Ulson de Souza, Selene Maria de Arruda; Ulson de Souza, Antônio Augusto; Andrade, Cristiano José de (Eng, 2024)
This study investigates the biodegradation of Reactive Red 141 (RR 141), an azo dye prevalent in the textile industry, by bacteria isolated from activated sludge in a textile effluent treatment plant. RR 141, characterized by nitrogen–nitrogen double bonds (-N=N-), contributes to environmental issues when improperly disposed of in textile effluents, leading to reduced oxygen levels in water bodies, diminished sunlight penetration, and the formation of potentially carcinogenic and mutagenic aromatic amines. This research focuses on identifying bacteria from activated sludge with the potential to decolorize RR 141. Microbiological identification employs MALDI-TOF-MS, known for its precision and rapid identification of environmental bacteria, enhancing treatment efficiency. Results highlight Bacillus thuringiensis and Kosakonia radicincitans as the most promising strains for RR 141 decolorization. Analysis of micro-organisms in activated sludge and database exploration suggests a correlation between these strains and the decolorization process. It is worth noting that this is the first report on the potential use of K. radicincitans for azo dye decolorization. Three distinct culture media—BHI, MSG, and MS—were assessed to investigate their impact on RR 141 decolorization. Notably, BHI and MSG media, incorporating a carbon source, facilitated the bacterial growth of both tested species (B. thuringiensis and K. radicincitans), a phenomenon absent in the MS medium. This observation suggests that the bacteria exhibit limited capability to utilize RR 141 dye as a carbon source, pointing towards the influence of the culture medium on the discoloration process. The study evaluates performance kinetics, decolorization capacity through UV-VIS spectrophotometry, potential degradation pathways via HPLC-MS analysis, phytotoxicity, and enzymatic activity identification. B. thuringiensis and K. radicincitans exhibit potential in decolorizing RR141, with 38% and 26% removal individually in 120 h. As a consortium, they achieved 36% removal in 12 h, primarily through biosorption rather than biodegradation, as indicated by HPLC-MS analyses. In conclusion, the research emphasizes the importance of exploring bacteria from activated sludge to optimize azo dye degradation in textile effluents. B. thuringiensis and K. radicincitans emerge as promising candidates for bioremediation, and the application of MALDI-TOF-MS proves invaluable for rapid and precise bacteria identification.
CRIS-Team Scopus Importer:2024-04-05
Keywords: Bacillus thuringiensis; biodegradation; Kosakonia radicincitans; MALDI-TOF MS; Reactive Red 141; toxicity

Selective and caspase-independent cytotoxicity of bioactive glasses towards giant cell tumor of bone derived neoplastic stromal cells but not to bone marrow derived stromal cells. - Westhauser, Fabian; Arango Ospina, Marcela; Losch, Sarina; Wilkesmann, Sebastian; Lehner, Burkhard; Ali, Muhammad Saad; Peukert, Wolfgang; Boccaccini, Aldo R.; Fellenberg, Jörg (Biomaterials, 2021)
Semi-malignant giant cell tumors of bone (GCTB) are associated with large osteolytic defects and significant bone destructions. Surgical resection remains the standard therapy that is, however, associated with very high recurrence rates. Bioactive glasses (BGs) that are osteogenic but under certain conditions also cytotoxic might be suitable to achieve biological reconstruction with simultaneous reduction of tumor recurrence in GCTB. In this study, a concentration and time dependent cytotoxic effect of five different BG compositions towards neoplastic GCTB cells was identified while bone marrow derived mesenchymal stromal cells were mostly unaffected. Time course and extent of the cytotoxic effect were dependent on the BG composition and were not associated with caspases activation, indicating that apoptotic mechanisms are not involved. Rather, detection of BG-induced disruption of the cell membranes and a rapid drop of intracellular HMG1 (High Mobility Group Box 1 protein) levels suggest a necrotic cell death. Notably, the cytotoxic effects were dependent on a direct contact of cells and BGs and could not be observed using indirect cultivation settings. Our data suggest that BGs might represent promising materials for the treatment of GCTB in order to reduce tumor recurrence with simultaneous enhancement of bone regeneration.
Keywords: Apoptosis; Bioactive glass; Caspases; Cytotoxicity; Giant cell tumor of bone; Mesenchymal stromal cells; Necrosis

Self-adhesive resin cements: pH-neutralization, hydrophilicity, and hygroscopic expansion stress - Rödel, Lena; Bednarzig, Vera; Belli, Renan; Petschelt, Anselm; Lohbauer, Ulrich; Zorzin, José Ignacio (Clinical Oral Investigations, 2016)
The objective of the study was to investigate the relationship between pH-neutralization, hydrophilicity, and free hygroscopic expansion stress of self-adhesive resin cements (SARCs) after storage in artificial saliva.The SARCs RelyX Unicem Automix 2 (RX2, 3 M ESPE), iCEM (iCEM, Heraeus) and Maxcem Elite (MCE, Kerr) were under investigation in this study. Cylinders (height × diameter, 6 × 4mm) were prepared from each material and stored in artificial saliva (7d at 37 °C). Cylinder height was measured at baseline and after 7 days. After storage, the compression modulus was measured to calculate the free hygroscopic expansion stress. For pH-neutralization and hydrophilicity assessment, disks (height × diameter, 1 × 1.5 mm) were prepared, covered with electrolyte, and monitored over 24 h at 37 °C. Hydrophilicity was assessed using the static sessile drop technique at baseline and at different time intervals up to 24 h. Data were analyzed using one-way ANOVA and post hoc Student-Newman-Keuls test (S-N-K, ? = 0.05).After 24 h, RX2 (pH24h 4.68) had a significantly higher (p < 0.05) pH-value than MCE (pH24h 4.2) and iCEM (pH24h 3.23). iCEM showed the significantly highest hydrophilicity (p < 0.05) after 24 h (?24h 85.02°), while MCE resulted lower (?24h 113.01°) in comparison with RX2 (?24h 108.11°). The resulting hygroscopic expansion stress of iCEM (29.15 MPa) was significantly higher (p < 0.05) compared to RX2 (14.5 MPa) and MCE (21.02 MPa).The material with lowest pH-neutralization capacity displayed higher hydrophilicity after 24 h and higher hygroscopic expansion stress after 7 days compared to those with high pH-neutralization.Remnant hydrophilicity due to low pH-neutralization of SARCs could lead to cement interface stress build-up and long-term failure of silicate ceramic restorations.
EVALuna2:24695

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Ultrasonic pulse velocity testing and image analysis were used to predict the thermal stability of cordierite-mullite refractories. Two compositions used as substrates in fast firing of porcelain whiteware, characterized by different microstructure and crack propagation behavior, were investigated. Fracture strength and fracture toughness values were obtained from three point bending test and chevron notched specimen technique, respectively. The measurement of the ultrasonic velocity was used to assess the material degradation with increasing number of thermal-shock cycles and specimen damage was monitored using image analysis to obtain further evidence of material degradation. The correlation between thermo-mechanical properties, ultrasonic velocity, microstructure, crack-propagation behavior and thermal-shock resistance was discussed. A remarkable similarity was found between the variation of ultrasonic velocity (when measured through the length of the refractory plates) and fracture strength with number of thermal shock cycles. On the other hand, the development of surface microcracking, as monitored by image analysis, is in good agreement with the variation of K IC with the number of thermal-shock cycles. The variation of the fracdσrmdE rm dyn

Setting behavior and bioactivity assessment of calcium carbonate cements - Rodríguez-Sánchez, Jesús; Myszka, Barbara; Boccaccini, Aldo R.; Dysthe, Dag Kristian (Journal of the American Ceramic Society, 2019)
Calcium carbonate cements have emerged in the last few years as an attractive candidate for biomedical applications. They can be easily prepared by mixing water with two metastable calcium carbonate phases––amorphous calcium carbonate (ACC) and vaterite––which (re)crystallize into calcite during setting reaction. The transformation kinetics (and therefore the final surface cement composition) strongly depends on the initial mixture design and is controlled by the dissolution of ACC, whereas calcite nucleation typically controls their recrystallization in fluid batch experiments. Novel compositions are presented in this paper by incorporating organic molecules as a proxy to test their capability to carry on other biomolecules like proteins or antibiotics. The hardened samples are microporous and show excellent bioactivity rates, although their mechanical properties still remain poor. However, this would not be a handicap for in-vivo applications such as bone filling, especially in low mechanical stress locations.
CRIS-Team Scopus Importer:2019-09-17
Keywords: (re)crystallization kinetics; apatite-like precipitation; bioactivity; CaCO; compressive strength

Shape Matters: Crystal Morphology and Surface Topography Alter Bioactivity of Bioceramics in Simulated Body Fluid - Myszka, Barbara; Schodder, Philipp; Leupold, Simon; Barr, Maissa; Hurle, Katrin; Schüßler, Martina; Demmert, Benedikt; Biggemann, Jonas; Fey, Tobias; Boccaccini, Aldo R.; Wolf, Stephan (Advanced Engineering Materials, 2020)
For bioactive biomaterials such as bioceramics and bioglass, it is generally accepted that, apart from acting as heterogeneous nucleators, it is their solubility and the resulting release of relevant ions such as calcium or basic anions which mainly governs the biomaterial's bioactivity. This contribution reveals that this bioactivity, as assessed by simulated body fluid (SBF), can also be considerably modified by the bioceramic's morphology, i.e., bioactivity is also governed by microstructure and surface morphology. When crystals are forced to adopt out-of-equilibrium crystal habit, this simple change in morphology converts an essentially bioinert material, here calcite, into a bioceramic which shows bioactivity in SBF. On larger length scales, already simple morphological changes, such as scratches, can have inverse effects. Limited mass transport into grooves and pits on a bioceramic surface can lead to local ion depletion which, in turn, causes reduced bioactivity of bioceramics which, otherwise, show distinct bioactivity in SBF. This contribution emblematically illustrates the unforeseen importance of even minor morphology changes on different length scales when assessing and designing a biomaterial's bioactivity through SBF assays.
CRIS-Team Scopus Importer:2020-06-05
Keywords: bioactivity; bioceramics; biomaterials; calcium carbonate; crystallization

Silibinin releasing mesoporous bioactive glass nanoparticles with potential for breast cancer therapy - Nawaz, Qaisar; Fuentes-Chandía, Miguel; Tharmalingam, Varun; Ur Rehman, Muhammad Atiq; Leal-Egaña, Aldo; Boccaccini, Aldo R. (Ceramics International, 2020)
Mesoporous materials have attracted extensive consideration in the field of drug delivery. The targeted release of anti-neoplastic agents depends on the carrier used to transport such drugs in the body. In this study, mesoporous bioactive glass nanoparticles (MBGN) of an average size of 120 ± 10 nm were used to load and release silibinin, which is a natural flavonolignan used as anticancer agent and tumor suppressor. Mesoporous bioactive glass nanoparticles were characterized in terms of morphology and release potential after being loaded with silibinin. The loading and release amounts of silibinin were quantified using UV-VIS spectrophotometer at λmax = 280 nm in PBS buffer solution (pH 7.4). It was found that MBGN have a maximum loading efficiency of 61% against optimal silibinin concentration (i.e. 40 μg/ml silibinin in PBS buffer solution (pH 7.4)). The drug was released in a sustained manner from loaded mesoporous bioactive glass nanoparticles and a release of 18 μg/ml silibinin was measured during the first 24 h post-drug loading. Further, the chemotherapeutic effect of silibinin was tested on metastatic MDA-MB-231 breast cells and the non-metastatic breast cell line MCF-10A at two different concentrations (9.0 μg/ml and 18 μg/ml). As our results show, silibinin exhibits a chemotherapeutic potential towards MDA-MB-231 cell line, which is a much lower concentration compared to values reported in literature. According to our knowledge, this is the first study elucidating the use of MBGN as a carrier for silibinin, as well as testing its lethal effect in contact with breast neoplastic cells. Taken collectively, the results of the present study suggest that silibinin-loaded MBGN can be applied as an effective drug delivery system to cause a chemo preventive response which has the potential to be beneficial for the treatment of breast cancer.
CRIS-Team Scopus Importer:2020-09-11
Keywords: Antineoplastic drug carrier; Bioactive glass; Biomaterials for cancer research; Drug delivery system; Mesoporous nanoparticles; Silibinin

Silicate-based nanoceramics in regenerative medicine - Arango Ospina, Marcela; Nawaz, Qaisar; Boccaccini, Aldo R. (Nanostructured Biomaterials for Regenerative Medicine, 2020)
Silicate-based bioactive nanoceramics, such as bioactive glasses, glass-ceramics, and mesoporous systems play an important role in biomedical applications, tissue engineering, bioimaging, and drug delivery systems. The structure and chemistry of these inorganic materials can be tailored to achieve controlled degradation rate that mimics the new tissue growth rate. Furthermore, these materials are combined with different polymeric systems to form nanocomposites with enhanced mechanical properties and improved biological performance. This chapter provides an overview of the processing and application of different silicate-based nanoceramics and bioactive glasses. It also addresses the interaction of silicate-based systems with the biological environment, giving a brief overview on the applications of bioactive silicate nanoparticles in bone regeneration, soft tissue repair, and as targeted drug delivery carriers.<br
CRIS-Team WoS Importer:2020-05-26
Keywords: Silicate-based nanoceramics; Silicate-based bioactive glasses; Tissue engineering; Mesoporous systems; Drug delivery

Silver-containing bioactive glasses for tissue engineering applications - Boccaccini, Aldo R.; Diba, Mani (Elsevier Ltd, 2014)
Bioactive glasses have shown promising results for tissue engineering applications. Specific metallic ions can be used for doping these materials to induce enhanced biological performance. Silver is an element well-known for its antibacterial properties. This chapter present an overview of Ag-doped bioactive glasses including their synthesis, properties and applications in tissue engineering. Moreover, the reported effects of Ag-doping on the properties of bioactive glasses are discussed. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Antibacterial materials; Bioactive glass; Biodegradable materials; Silver; Tissue engineering

Simple fabrication technique for multilayered stratified composite scaffolds suitable for interface tissue engineering - Liverani, Liliana; Roether, Judith; Nooeaid, Patcharakamon; Trombetta, Marcella; Schubert, Dirk W.; Boccaccini, Aldo R. (Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2012)
A straightforward method for manufacturing stratified scaffolds with potential application in osteochondral tissue engineering is reported. The method integrates three different techniques widely used for scaffold fabrication: sponge replica method, freeze-drying and electrospinning. 45S5 Bioglass® was used for the fabrication of the rigid bioactive substrate intended to be in contact with bone tissue, chitosan and alginate based solutions were used for building the interface between the Bioglass®-based scaffold and the soft cartilage side of the construct. Finally a chitosan-based electrospun nanofibrous membrane was selected for the upper layer of the scaffold. In this design, the intermediate layer has multiple functions providing adherence between the other scaffold components, preventing delamination and acting as a soft coating for the rigid Bioglass® substrate. Morphological analysis, bioactivity tests in simulated body fluid (SBF), as well as mechanical and wettability tests were performed on all samples to assess the optimal stratified scaffold combination. The best results, in terms of resistance to layer delamination, preservation of the bioactivity and improvement of the mechanical properties, were obtained using a chitosan solution and the freeze gelation technique for fabrication of the intermediate layer. Key results are discussed in the context of the potential application of these novel scaffolds in osteochondral tissue engineering.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.simple
Keywords: Composites; Tissue engineering; Scaffolds; Electrospinning; Chitosan; Bioactive glass

Simple methods to fabricate Bioglass (R)-derived glass-ceramic scaffolds exhibiting porosity gradient - Bretcanu, Oana; Samaille, Claire; Boccaccini, Aldo R. (Journal of Materials Science, 2008)
The present paper discusses different processing technologies for fabrication of novel 45S5 Bioglass®-derived glass-ceramic scaffolds with tailored porosity gradient for potential application in bone tissue engineering. Different types of scaffolds with continuous or stepwise gradient of porosity were produced by the foam replication technique, using preformed polyurethane (PU) foams as sacrificial templates. After preforming the PU foams in metallic moulds, they were dipped in a 45S5 Bioglass ®-based slurry and subsequently heat treated in a chamber furnace up to 1100 °C. During heating, the organic phase is burned out and the glass sinters and partially crystallises. By using this new approach, Bioglass®-derived glass-ceramic scaffolds with different shapes and porosity profiles were designed. Scanning electron microscopy (SEM) showed that all samples have highly interconnected porous structure, with specific porosity gradients. By modifying the shape and dimensions of the metallic mould, bioactive glass-ceramic scaffolds with complex shapes and different degrees of porosity gradient could be obtained. © 2008 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.simple

Single-step electrochemical deposition of antimicrobial orthopaedic coatings based on a bioactive glass/chitosan/nano-silver composite system - Pishbin, F.; Mourino, V.; Gilchrist, J. B.; Mccomb, D. W.; Kreppel, S.; Salih, V.; Ryan, M. P.; Boccaccini, Aldo R. (Acta Biomaterialia, 2013)
Composite orthopaedic coatings with antibacterial capability containing chitosan, Bioglass® particles (9.8 μm) and silver nanoparticles (Ag-np) were fabricated using a single-step electrophoretic deposition (EPD) technique, and their structural and preliminary in vitro bactericidal and cellular properties were investigated. Stainless steel 316 was used as a standard metallic orthopaedic substrate. The coatings were compared with EPD coatings of chitosan and chitosan/Bioglass®. The ability of chitosan as both a complexing and stabilizing agent was utilized to form uniformly deposited Ag-np. Due to the presence of Bioglass® particles, the coatings were bioactive in terms of forming carbonated hydroxyapatite in simulated body fluid (SBF). Less than 7 wt.% of the incorporated silver was released over the course of 28 days in SBF and the possibility of manipulating the release rate by varying the deposition order of coating layers was shown. The low released concentration of Ag ions (<2.5 ppm) was efficiently antibacterial against Staphyloccocus aureus up to 10 days. Although chitosan and chitosan/Bioglass® coating supported proliferation of MG-63 osteoblast-like cells up to 7 days of culture, chitosan/Bioglass®/Ag-np coatings containing 342 μg of Ag-np showed cytotoxic effects. This was attributed to the relatively high concentration of Ag-np incorporated in the coatings. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.single
Keywords: Bioglass®; Chitosan; Composite coatings; Electrophoretic deposition; Silver nanoparticles

Sintering and crystallisation of 45S5 Bioglass (R) powder - Bretcanu, Oana; Chatzistavrou, Xanthippi; Paraskevopoulos, Konstantinos; Conradt, Reinhard; Thompson, Ian; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2009)
The sintering process of 45S5 Bioglass® powder (mean particle size < 5 μm) was investigated by using different thermal analysis methods. Heating microscopy and conventional dilatometry techniques showed that bioactive glass sinters in two major steps: a short stage in the temperature range 500-600 °C and a longer stage in the range 850-1100 °C. The optimal sintering temperature and time were found to be 1050 °C and 140 min, respectively. Differential thermal analysis (DTA) showed that Bioglass® crystallises at temperatures between 600 and 750 °C. The characteristic crystalline phases were identified by Fourier Transformed Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). The crystallisation kinetics was studied by DTA, using a non-isothermal method. The Kissinger plot for Bioglass® powder heated at different heating rates between 5 and 30 °C/min yielded an activation energy of 316 kJ/mol. The average value of Avrami parameter determined using the Augis-Bennett method was 0.95 ± 0.10, confirming a surface crystallisation mechanism. After sintering at 1050 °C for 140 min, the main crystalline phase was found to be Na2Ca2Si3O9. The results of this work are useful for the design of the sintering/crystallisation heat treatment of Bioglass® powder which is used for fabricating tissue engineering scaffolds with varying degree of bioactivity. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.sinter
Keywords: A. Sintering; B. Microstructure-final; Bioglass; C. Thermal properties; E. Structural applications

Sintering and crystallization kinetics of bioactive glass 13–93 - Blaeß, C.; Müller, R.; Boccaccini, Aldo R. (Journal of Non-Crystalline Solids, 2024)
This study investigates the sintering and crystallization behavior and kinetic of the bioactive glass (BG) 13–93 with nominal composition (in mol%): 54.6 SiO2 - 1.7 P2O3 - 22.1 CaO - 6.0 Na2O - 7.9 K2O - 7.7 MgO. Sintering and crystallization were investigated non-isothermally for various particle size fractions smaller than 315 µm as well as for bulk samples. Densification was not hindered by the presence of crystalline phases across all particle size fractions. Afterwards, wollastonite was found as the dominant crystal phase at higher temperature which resorb primary surface precipitation-like quartz crystallites. The growth direction shifts into volume when the sample surface is nearly covered. The crystal growth rate of wollastonite was calculated from the crystalline surface layer thickness measured during heating. The findings of this study are relevant for the high temperature processing of BG 13–93.
CRIS-Team Scopus Importer:2024-01-19
Keywords: Bioactive glass; Crystallization; Sintering