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

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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

Sintering densification curve - a practical approach for its construction from dilatometric shrinkage data - Maca, K.; Pouchly, V.; Boccaccini, Aldo R. (Science of Sintering, 2008)
This article summarizes the usage of high-temperature dilatometry in ceramic processing and powder technology with special attention on the description of the sintering process. A practical method for transformation of dilatometric shrinkage data into densification curves (the dependence of the sample density on sintering temperature or time) is described in detail. A new automatic procedure to recalculate sintering shrinkage data allowing the plot of the densification curve has been developed, which is presented here.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.sinter
Keywords: Densification curve; High-temperature dilatometry; Sintering shrinkage

SiO2–CaO rod-like particles in chitosan matrix as bioactive coatings for stainless steel implants - Katunar, María Rosa; Diaz, Florencia; Boccaccini, Aldo R.; Ballarre, Josefina (Ceramics International, 2023)
Metals have outstanding mechanical properties, being capable of supporting the combined stresses applied to biomaterials (e.g. orthopaedic implants) by the human body. Metals can be biocompatible (such as Ti or stainless steel) but they are bioinert, they generally do not generate a natural bonding with bone tissue, and it is then necessary to produce a kind of anchor or external fixation to improve the implant-bone interface. The surface chemistry and morphology of stainless steel, a material widely used for orthopaedic implants, can affect the interaction of the implant with the surrounding medium and cell attachment and growth, thus affecting the compatibility between the host tissue and the material. The aim of this work is to enhance the bioactivity of stainless steel implants by the application of a combined coating of chitosan and bioactive silica-calcia (SiCa) rod-shaped particles. Stainless steel substrates were coated in two different concentrations of SiCa particles produced by the Stöber method, immersed in a chitosan matrix via electrophoretic deposition. Thick and homogeneous coatings were achieved following the optimization of the deposition parameters, with average thicknesses between 12 and 19 μm. Although the coating exhibited fast rates of dissolution, the formation of carbonated calcium phosphate could be observed after immersion for 10 days in simulated body fluid (SBF), in microscopic images, which was confirmed via spectroscopic analysis. Murine stromal ST-2 cell proliferation was found after 4 and 10 days of seeding, indicating that the coating was not toxic and able to sustain the adhesion and growth of ST-2 cells.
CRIS-Team Scopus Importer:2023-10-06
Keywords: Biopolymers; Cell attachment; Electrophoretic deposition; Functional coatings; Silica-calcia particles

Soft bioactive coatings based on electrophoretically deposited bioactive glass nanoparticles and polycaprolactone - Graubmann, Julia; Seuß, Sigrid; Boccaccini, Aldo R. (10th IASTED International Conference on Biomedical Engineering, BioMed 2013, 2013)
In this study composite coatings of polycaprolactone (PCL) and nanosized bioactive glass were produced on stainless steel by electrophoretic deposition (EPD) for biomedical applications. PCL was dissolved in dimethylcarbonate and bioactive glass nanoparticles were dispersed in ethanol for the deposition. The EPD parameters were varied in terms of voltage, deposition time, concentration of PCL and bioactive glass (BG) and pH. SEM showed that homogeneous composite coatings of about 5LIHI thickness were produced. Contact angle measurements indicated that the contact angle and hence the hydrophobicity of the coatings decreases with increasing BG content. The bioactivity of the coatings was investigated by assessing the formation of hydroxyapatite on coating surfaces in simulated body fluid for up to 15 days and investigating the samples by Raman spectroscopy and SEM. EPD was confirmed to be a suitable technique to produce composite coatings based on nanosized bioactive glass and PCL, which are of interest as soft (deformable) bioactive coating in orthopedic applications.
Keywords: Biomedical coatings; Electrophoretic deposition; Nanoscale bioactive glass; Polycaprolactone

Soft–matrices based on Fibrous Proteins for Biofabrication - Silva Lourenco, Rauqel; Sarker, Bapi; Singh, Raminder; Cicha, Iwona; Roether, Judith; Kaschta, Joachim; Detsch, Rainer; Garlichs, Christoph; Schubert, Dirk W.; Boccaccini, Aldo R. (14th BIONANO-MATERIALS, 2013)

Soft-matrices based on silk fibroin and alginate for tissue engineering - Silva, Raquel; Singh, Raminder; Sarker, Bapi; Papageorgiou, Dimitrios G.; Juhasz, Judith A.; Roether, Judith; Cicha, Iwona; Kaschta, Joachim; Schubert, Dirk W.; Chrissafis, Konstantinos; Detsch, Rainer; Boccaccini, Aldo R. (International Journal of Biological Macromolecules, 2016)
Keywords: Alginate; Endothelial cells; Silk fibroin; Soft-matrix; Tissue engineering

Sol-gel based fabrication and characterization of new bioactive glass-ceramic composites for dental applications - Chatzistavrou, Xanthippi; Tsigkou, Olga; Amin, Harsh D.; Paraskevopoulos, Konstantinos M.; Salih, Vehid; Boccaccini, Aldo R. (Journal of the European Ceramic Society, 2012)
The fabrication of a new composite glass-ceramic with potential application in dental restoration was investigated. The developed material aims to modify the surface of dental ceramics creating bioactive surfaces able to improve material-cell interaction enhancing the bonding of the marginal gap between restoration and tooth. The application of the sol-gel method led to a microporous homogeneous glass-ceramic which can be applied as coating on commercial dental ceramic substrates. The microstructural, thermal, mechanical and biological properties of the fabricated coatings were studied and compared to the respective results of a previously investigated glass-ceramic composite. The material-cell interaction on these two sol-gel dental composites was studied in detail. The attachment and proliferation of both periodontal ligament and gingival fibroblast cells confirmed the bioactive behavior of the new materials and their ability to be potentially applied in dental restorations for soft tissue regeneration and sealing of the marginal gap. © 2012 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.solgel
Keywords: Biomedical applications; Composites; Dental ceramics; Glass-ceramics; Sol-gel processes

Sol-gel based fabrication of novel glass-ceramics and composites for dental applications - Chatzistavrou, X.; Esteve, D.; Hatzistavrou, E.; Kontonasaki, E.; Paraskevopoulos, K. M.; Boccaccini, Aldo R. (Materials Science and Engineering C, 2010)
The aim of this study is the fabrication of dental glass-ceramics able to elicit bioactive behaviour around the margins of fixed restorations and to provide a bioactive surface which can lead to periodontal tissue attachment, providing complete sealing of the marginal gap between tooth and fixed prosthesis. Sol-gel technique is applied for the fabrication of a new glass-ceramic in the system SiO260%-P2O 53%-Al2O314%-CaO6%-Na2O7%-K 2O10% (wt.%) and a related composite material combining this phase with the bioactive glass 58S. This composite material aims to create a bioactive surface which could lead to periodontal tissue attachment, providing complete sealing of the marginal gap between tooth and fixed prosthesis. The microstructural and thermal properties and the bioactive behaviour of the new materials were determined and were observed to be similar in respect to a commercial leucite based fluorapatite dental glass-ceramic. The feasibility of the new composite material to be applied as coating on the base porcelain as well as the bioactive behaviour of the fabricated coated specimes were confirmed. © 2010 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.solgel
Keywords: Bioactive glass-ceramics; Coating; Dental application; Simulated Body Fluid; Sol-gel method

Sol-gel bioactive glass containing biomaterials for restorative dentistry: A review - Simila, Hazel; Boccaccini, Aldo R. (Dental Materials, 2022)
Objective: Bioactive glasses (BAGs) have been researched extensively for dentistry due to their favourable biocompatibility and hard tissue bonding ability. However, the specific application of BAGs produced through sol-gel synthesis in restorative dentistry has not been reviewed previously. This review provides a comprehensive account of the principles behind sol-gel derived BAGs and their investigation for dental tissue restoration materials. Methods: A search for in vitro and in vivo studies was performed using the databases Web of Science®, Medline®, Scopus® and Google Scholar®. Articles published over the past 20 years were selected and data on the BAG composition and morphology was extracted. Analysis of the effect of specific BAG additives on the properties of experimental dental materials was also performed. Results: A majority of BAG particles investigated were spheres ranging in size from 5 nm to 650 µm. Sol-gel BAGs are mainly applied in the treatment of hypersensitive dentine and for pulp-dentine tissue engineering, while a handful have been used in target drug delivery. BAG fillers are promising additives that result in improved biological properties, antibacterial effects, hardness, acid buffering and remineralization. Unfortunately, some detrimental effects on optical properties have been observed with BAG addition. Additionally, in vivo data, investigations into radiopacity and standardization of test protocols are identified as areas for improvement and further studies. Significance: Future work should consider the pertinent issues raised in order to improve the quality of available data and expand knowledge in this area of dental biomaterials research and development.
CRIS-Team Scopus Importer:2022-03-25
Keywords: Antibacterial; Bioactivity; Cytotoxicity; Dental material; Ion release; pH; Properties; Restorative dentistry; Sol-gel synthesis

Sol-gel coatings incorporating borosilicate bioactive glass enhance anti corrosive and surface performance of stainless steel implants - Balestriere, M. A.; Schuhladen, Katharina; Herrera Seitz, K.; Boccaccini, Aldo R.; Cere, S. M.; Ballarre, J. (Journal of Electroanalytical Chemistry, 2020)
Metals are the most used materials as orthopaedic or dental implants due to their excellent mechanical properties. Stainless steel is one of the most commonly used materials based on its excellent mechanical properties and low costs compared with other metals, e.g. titanium alloys. In developing countries it is still one of the most used materials for temporary devices like bone plates and fixation screws and for permanent orthopaedic implants. However, stainless steel does not have good anticorrosive and bioactive surface properties in physiological media in comparison to other metals: stainless steel is not able to create a natural bonding with bone and might release corrosion products that could finally end in the removal of the implant. A promising approach to avoid those effects is to protect the implant with a functional coating, which additionally may have antibacterial properties. In this work, three kinds of bioactive glass particles (silicate, borosilicate and copper-doped borosilicate) were added as a second phase to a hybrid organic-inorganic silica based sol-gel made coating, with the aim of improving the surface properties of stainless steel as implant material. Chemical composition of the particles and coatings as well as the bioactive and anti-corrosive behaviour of the generated coating systems were analysed by Fourier Transformed Infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and by electrochemical tests. After 14 days of immersion in simulated body fluid solution, the particles contained in the coatings presented a slow dissolution, generating phosphate-rich deposits (first insight of bioactivity) and enhancing the electrochemical response.
CRIS-Team Scopus Importer:2020-10-23
Keywords: Bioactivity; Corrosion protection; Cu-borosilicate bioactive glass; Sol-gel; Stainless steel

Sol-gel derived B2O3-CaO borate bioactive glasses with hemostatic, antibacterial and pro-angiogenic activities - Zheng, Kai; Bider, Faina; Monavari, Mahshid; Xu, Zhiyan; Janko, Christina; Alexiou, Christoph; Beltrán, Ana M.; Boccaccini, Aldo R. (Regenerative Biomaterials, 2024)
Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.
CRIS-Team Scopus Importer:2024-02-02
Keywords: borate glasses; glass composition; sol-gel processing; wound healing

Sol-gel derived bioactive glass ceramics for dental applications - Boccaccini, Aldo R.; et al. (Woodhead Publishing, 2012)
Sol-gel derived silica-based bioactive glasses and ceramics attain many advantages owing to silicon which has a beneficial role in bone formation in vivo. They exhibit mesoporous architecture with interconnected pore structure and a high specific surface area that positively affects their bioactivity. Their compositions of up to 100mol% SiO in binary, ternary or quaternary systems, the potential for varying the microstructure in the same composition by controlling the chemical reactions and their ability to form scaffolds are some of the unique properties that distinguish them from their melt-derived counterparts. In the field of dental restoration and regeneration, sol-gel silica-based bioactive composites have started to emerge in various applications including coatings, scaffolds and dental tissue regeneration. © 2013 Woodhead Publishing Limited All rights reserved.
Keywords: Bioactivity; Silica-based ceramics; Silica-based glasses; Sol-gel coatings; Sol-gel dental composites; Sol-gel synthesis

Sol-Gel Fabrication of Glass-Ceramic Composite Materials for Dental Application - Chatzistavrou, Xanthipi; Esteve, D.; Hatzistavrou, E.; Kontonasaki, Eleana; Paraskevopoulos, Konstantinos; Boccaccini, Aldo R. (Bioceramics Development and Applications, 2011)
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.solgel

Sol-gel processing and characterization of binary P2O5-CaO and ternary P2O5-CaO-Li2O mesoporous phosphate bioactive glasses - Li, Chunde; Wang, Chen; Boccaccini, Aldo R.; Zheng, Kai (Journal of Non-Crystalline Solids: X, 2023)
Mesoporous phosphate bioactive glasses (MPBGs) are novel and attractive biomaterials for biomedical applications. Here we report the sol-gel processing of P2O5-CaO and P2O5-CaO-Li2O MPBGs using Pluronic P123 as the surfactant. Our results showed that P123 could act as a crystallization inhibitor, thus extending the composition range of MPBGs. The concentration of CaO from 40 to 55 mol% in P2O5-CaO MPBGs did not affect the phosphate chain structure and mesoporous morphology. However, the specific surface area and pore volume were slightly enhanced with the increased CaO concentration. In ternary P2O5-CaO-Li2O MPBGs, the increase in Li2O concentration (from 5 to 20 mol%) did not alter the phosphate chain structure and mesoporous morphology. However, 20 mol% Li2O incorporation induced crystallization. Binary and ternary MPBGs showed relatively low acellular bioactivity as indicated by the slow formation of hydroxyapatite in physiological fluids. Sol-gel processing is a feasible strategy for synthesizing P2O5-CaO and P2O5-CaO-Li2O MPBGs.
CRIS-Team Scopus Importer:2023-02-10
Keywords: Bioactive glasses; lithium; Mesoporous materials; Phosphate glasses; Sol-gel processing

Sol-gel processing of bioactive glass nanoparticles: A review - Zheng, Kai; Boccaccini, Aldo R. (Advances in Colloid and Interface Science, 2017)
Keywords: Bioactive glasses; Biomedical applications; Fabrication strategies; Nanoparticles; Sol-gel processing

Sol-gel processing of novel bioactive Mg-containing silicate scaffolds for alveolar bone regeneration - Goudouri, Ourania Menti; Vogel, Caroline; Grünewald, Alina; Detsch, Rainer; Kontonasaki, Eleana; Boccaccini, Aldo R. (Journal of Biomaterials Applications, 2016)
Periodontal tissue regeneration is an important application area of biomaterials, given the large proportion of the population affected by periodontal diseases like periodontitis. The aim of this study was the synthesis of a novel porous bioceramic scaffold in the SiO-CaO-MgO system with specific properties targeted for alveolar bone tissue regeneration using a modification of the traditional foam replica technique. Since bioceramic scaffolds are considered brittle, scaffolds were also coated with gelatin in order to increase their mechanical stability. Gelatin was chosen for its biocompatibility, biodegradability, low-cost, and low immunogenicity. However, gelatin degrades very fast in water solutions. For this reason, two different cross-linking agents were evaluated. Genipin, a non-toxic gardenia extract and the chemical compound 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in combination with N-hydroxysuccinimide (NHS), which is also considered non-toxic. The results of the investigation indicated that all scaffolds presented an open, interconnected porosity and pores' sizes in the range of 300-600 1/4m, fast apatite-forming ability, biocompatibility, and suitable mechanical stability.
Keywords: alveolar bone regeneration; biocompatibility; gelatin; Mg-containing silicate scaffolds; sol-gel

Sol-gel route to carbon nanotube borosilicate glass composites - Thomas, Boris J. C.; Shaffer, Milo S. P.; Boccaccini, Aldo R. (Composites Part A-Applied Science and Manufacturing, 2009)
Dense borosilicate glass matrix composites containing up to 3 wt% of multiwalled carbon nanotubes were produced by a sol-gel process. The three different silicate precursors employed (tetramethylsilane (TMOS), methyltriethoxysilane (MTES) and methyltrimethoxysilane (MTMS)) yielded transparent xerogels which were subsequently crushed and densified by hot pressing at 800 °C. The dispersion of the carbon nanotubes was aided by using an organic-inorganic binder (3-aminopropyl triethoxysilane) which limited flocculation of the CNTs in the silica sol. After densification, the borosilicate glass composites containing up to 2 wt% CNTs showed significant improvements in hardness and compression strength, as well as thermal conductivity, whilst percolation effects lead to a dramatic increase in electrical conductivity above 1 wt%. This simple approach to disperse CNTs into a technical silicate glass matrix via the sol-gel process focusses specifically on the borosilicate system, but the procedure can be applied to produce other inorganic matrix composites containing CNTs. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.solgel
Keywords: A. Ceramic-matrix composites (CMCs); A. Glasses; B. Mechanical properties; D. Thermal analysis

Sol-gel synthesis of lithium doped mesoporous bioactive glass nanoparticles and tricalcium silicate for restorative dentistry: Comparative investigation of physico-chemical structure, antibacterial susceptibility and biocompatibility - Simila, Hazel; Boccaccini, Aldo R. (Frontiers in Bioengineering and Biotechnology, 2023)
Introduction: The sol-gel method for production of mesoporous bioactive glass nanoparticles (MBGNs) has been adapted to synthesize tricalcium silicate (TCS) particles which, when formulated with other additives, form the gold standard for dentine-pulp complex regeneration. Comparison of TCS and MBGNs obtained by sol-gel method is critical considering the results of the first ever clinical trials of sol-gel BAG as pulpotomy materials in children. Moreover, although lithium (Li) based glass ceramics have been long used as dental prostheses materials, doping of Li ion into MBGNs for targeted dental applications is yet to be investigated. The fact that lithium chloride benefits pulp regeneration in vitro also makes this a worthwhile undertaking. Therefore, this study aimed to synthesize TCS and MBGNs doped with Li by sol-gel method, and perform comparative characterizations of the obtained particles. Methods: TCS particles and MBGNs containing 0%, 5%, 10% and 20% Li were synthesized and particle morphology and chemical structure determined. Powder concentrations of 15mg/10 mL were incubated in artificial saliva (AS), Hank’s balanced saline solution (HBSS) and simulated body fluid (SBF), at 37°C for 28 days and pH evolution and apatite formation, monitored. Bactericidal effects against S. aureus and E. coli, as well as possible cytotoxicity against MG63 cells were also evaluated through turbidity measurements. Results: MBGNs were confirmed to be mesoporous spheres ranging in size from 123 nm to 194 nm, while TCS formed irregular nano-structured agglomerates whose size was generally larger and variable. From ICP-OES data, extremely low Li ion incorporation into MBGNs was detected. All particles had an alkalinizing effect on all immersion media, but TCS elevated pH the most. SBF resulted in apatite formation for all particle types as early as 3 days, but TCS appears to be the only particle to form apatite in AS at a similar period. Although all particles had an effect on both bacteria, this was pronounced for undoped MBGNs. Whereas all particles are biocompatible, MBGNs showed better antimicrobial properties while TCS particles were associated with greater bioactivity. Conclusion: Synergizing these effects in dental biomaterials may be a worthwhile undertaking and realistic data on bioactive compounds targeting dental application may be obtained by varying the immersion media.
CRIS-Team Scopus Importer:2023-05-05
Keywords: bioactive glass nanoparticles; lithium; property evaluation; restorative dental biomaterial; sol-gel; tricalcium silicate

Sol-gel template synthesis of BaTiO3 films with nano-periodic structures - Kawamura, Go; Ohara, Kazuhiro; Tan, Wai Kian; Muto, Hiroyuki; Yamaguchi, Kazuhiro; Boccaccini, Aldo R.; Matsuda, Atsunori (Materials Letters, 2018)
Keywords: Anodic aluminum oxide; Nanotube arrays; Sol-gel preparation; Ceramics; Nanopillar arrays

Solution Precursor Plasma Spraying (SPPS): A novel and simple process to obtain bioactive glass coatings - Canas, E.; Orts, M. J.; Boccaccini, Aldo R.; Sanchez, E. (Materials Letters, 2018)
Keywords: Simulated Body Fluid; Solution feedstock; Bioceramics; Microstructure; Solution Precursor Plasma Spraying; Bioactive glass coating

Sonochemical processing and characterization of composite materials based on soy protein and alginate containing micron-sized bioactive glass particles - Silva Lourenco, Rauqel; Bulut, Buse; Roether, Judith; Kaschta, Joachim; Schubert, Dirk W.; Boccaccini, Aldo R. (Journal of Molecular Structure, 2014)
Novel composite hydrogels based on the combination of natural polymers; namely alginate and soy protein isolate, and bioactive glass (BC) particles (mean size: 2 pm) were developed. For this purpose a sono-chemical approach was used and homogeneous composite hydrogels, incorporating two concentrations of BC particles, were successfully obtained. Further physico-chemical characterization was performed in order to evaluate the influence of each component on hydrogel properties. The water uptake ability, weight loss, protein release, as well as FTIR, SEM and DMTA characterization were carried out. The bio-mineralization process in simulated body fluid (SBF) was followed over time and the results demonstrated that the composite materials have the ability to form a surface apatite layer after 7 days in SBF. The design of novel composite hydrogels based on soy protein, alginate and BC can be a suitable approach for bone regeneration applications. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Alginate; Soy isolate protein; Bioactive glass; Hydrogel; Tissue engineering

Sonosynthesis of Vaterite-Type Calcium Carbonate - Juhasz-Bortuzzo, Judith; Myszka, Barbara; Silva, Raquel; Boccaccini, Aldo R. (Crystal Growth & Design, 2017)

Soy Protein-based composite hydrogels: Physico-chemical characterization and in vitro cytocompatibility - Tansaz, Samira; Singh, Raminder; Cicha, Iwona; Boccaccini, Aldo R. (Polymers, 2018)
Keywords: Tissue engineering; Bioactive glass nanoparticles; Composite hydrogels; Biocompatibility; Soy protein isolate; Human cells

Soy protein isolate/bioactive glass composite membranes: Processing and properties - Tansaz, Samira; Schulte, M.; Kneser, U.; Mohn, D.; Stark, W.; Roether, Judith; Cicha, Iwona; Boccaccini, Aldo R. (European Polymer Journal, 2018)
Keywords: Clotting assay; Cytocompatibility; Bioactive glass; Soy protein isolate; Wound dressing

Soy protein meets bioactive glass: Electrospun composite fibers for tissue engineering applications - Tansaz, Samira; Liverani, Liliana; Vester, Lars; Boccaccini, Aldo R. (Materials Letters, 2017)
Soy protein isolate (SPI) was used to produce electrospun nanofibers, intended for tissue engineering (TE) applications. For the first time electrospun composite fibers have been successfully fabricated by the addition of nano and micron-sized 45S5 bioactive glass (BG) powders to SPI solution. The influence of BG particles on electrospun fiber morphology and mechanical properties was investigated. Optimization of electrospun parameters with focus on environmental factors indicated the need to control humidity for SPI fibers fabrication.
Keywords: Soy protein isolate Electrospinning Bioactive glass Nanofibers Tissue engineering

Special Issue: Electrophoretic deposition of ceramics - Boccaccini, Aldo R.; Ferrari, Begona; Dickerson, James H.; Galassi, Carmen (Journal of the European Ceramic Society, 2016)

Special issue: ICCM-17: Composites in Biomedical Applications - Boccaccini, Aldo R.; Mano, J. F. (Composites Science and Technology, 2010)
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.specia

Spherical Calcium Phosphate Nanoparticle Fillers Allow Polymer Processing of Bone Fixation Devices with High Bioactivity - Mohn, Dirk; Ege, Duygu; Feldman, Kirill; Schneider, Oliver D.; Imfeld, Thomas; Boccaccini, Aldo R.; Stark, Wendelin J. (Polymer Engineering and Science, 2010)
Treatment of bone defects generally requires a fixation device. Biodegradable implants can often prevent second operations in contrast to metallic implants that are surgically removed after healing. In this study, we investigate the preparation of a bone fixation device with additional bioactivity by adding nanoparticulate amorphous tricalcium phosphate (ATCP) to improve bonding to bone. Medically approved poly(lactideco-glycolide) (PLGA) and spherical (ATCP) nanoparticles were blended directly or through a two-step approach, where ATCP was first dispersed in PLGA by solvent casting, extruded and hot pressed producing blocks and bone screws. The latter route yielded good particle dispersion while blending alone led to inhomogeneous mixtures. Samples were immersed in simulated body fluid and showed rapid formation of surface hydroxyapatite layers (examined by X-ray diffraction and scanning electron microscopy) already after 3 days, thus confirming very high bioactivity. Polymer degradation during processing and upon simulated implantation conditions was followed by gel permeation chromatography. The elevated temperature during extrusion was the strongest single factor contributing to PLGA degradation. Screws could be machined out of extruded cylinders and demonstrated the ability to process PLGA/ATCP 90/10 composites with regular workshop tools. These properties suggest the use of such composites as improved, bioactive, and degradable bone fixation systems particularly in oral and maxillofacial surgery. © 2009 Society of Plastics Engineers.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.spheri

SPIONs functionalized with small peptides for binding of lipopolysaccharide, a pathophysiologically relevant microbial product. - Karawacka, Weronika; Janko, Christina; Unterweger, Harald; Mühlberger, Marina; Lyer, Stefan; Taccardi, Nicola; Mokhir, Andriy; Jira, Wolfgang; Peukert, Wolfgang; Boccaccini, Aldo R.; Kolot, Mikhail; Strauss, Richard; et al. (Colloids and Surfaces B-Biointerfaces, 2018)
Systemic inflammation such as sepsis represents an acute life-threatening condition, to which often no timely remedy can be found. A promising strategy may be to functionalize magnetic nanoparticles with specific peptides, derived from the binding motives of agglutinating salivary proteins, that allow immobilization of pathogens. In this work, superparamagnetic iron oxide nanoparticles with stable polycondensed aminoalkylsilane layer were developed, to which the heterobifunctional linkers N-succinimidyl 3-(2-pyridyldithio)-propanoate (SDPD) and N-succinimidyl bromoacetate (SBA) were bound. These linkers were further chemoselectively reacted with the thiol group of singularly present cysteines of selected peptides. The resulting functional nanoparticles underwent a detailed physicochemical characterization. The biocompatibility of the primarily coated aminoalkylsilane particles was also investigated. To test the pathogen-binding efficacy of the particles, the lipopolysaccharide-immobilization capacity of the peptide-coated particles was compared with free peptides. Here, one particle-bound peptide species succeeded in capturing 90% of the toxin, whereas the degree of immobilization of the toxin with a system that varied in the sequence of the peptide dropped to 35%. With these promising results, we hope to develop extracorporeal magnetic clearance systems for removing pathogens from the human body in order to accelerate diagnosis and alleviate acute disease conditions such as sepsis.

Sponge-derived natural bioactive glass microspheres with self-assembled surface channel arrays opening into a hollow core for bone tissue and controlled drug release applications - Kaya, Murat; Bilican, Ismail; Mujtaba, Muhammad; Sargin, Idris; Erginer Haskoylu, Merve; Toksoy Oner, Ebru; Zheng, Kai; Boccaccini, Aldo R.; Cansaran-Duman, Demet; Onses, M. Serdar; Torun, Ilker; Akyuz, Lalehan; et al. (Chemical Engineering Journal, 2020)
Porous, bioactive microspheres have always been a dream material to biomedical scientists for bone regeneration and drug delivery applications due to their interconnectivity, unique pore geometry, encapsulation ability and porosity spanning macroscopic, microscopic and nanoscopic length scales. Extensive efforts have been made to produce such materials synthetically at a great cost of money, time and labor. Herein, naturally-assembled multifunctional, open-channeled and hollow bioactive micro silica spheres (diameter 209.4 ± 38.5 µm) were discovered in a marine sponge (Geodia macandrewii), by peeling the outer surface of the sterrasters using hydrogen fluoride. The obtained micro silica spheres exhibited valuable characteristics such as homogeneously distributed pores, a cavity in the center of the sphere, and channels (approx. 3000) opening from each pore into the central cavity. Simulated body fluid analysis demonstrated the bioactivity of the micro silica spheres; whereas, no bioactivity was recorded for the original untreated sterrasters. The non-cytotoxicity and osteogenic ability of the isolated microspheres were confirmed through osteoblast cell culture. Finally, these silica based porous microspheres were tested for controlled drug release capacity. The spheres showed excellent loading and release abilities for an anti-cancer drug, carboplatin, in simulated solutions and in human cancer cell culture, HeLa, through a real time cell analyzer system. The drug loading capacity of the porous beads was determined as 10.59%. Considering the unique biological and physicochemical properties, these novel bioactive silica spheres, which we name as giant macroporous silica (GMS), are promising materials for a range of applications including bone tissue engineering and drug delivery.
CRIS-Team Scopus Importer:2020-11-20
Keywords: Biosilica; Bone tissue; Drug release; Geodia; Macroporous silica; Porifera; Porous beads; Sterrasters

Stereolithographic Ceramic Manufacturing of High Strength Bioactive Glass - Gmeiner, Robert; Mitteramskogler, Gerald; Stampfl, Jürgen; Boccaccini, Aldo R. (International Journal of Applied Ceramic Technology, 2015)
Bioactive glasses and glass ceramics like the 45S5 formulation have been studied toward biocompatibility and biodegradability for years. Nevertheless, clinical applications as bone substitute or scaffold material are highly limited because of the often poor mechanical behavior of bioactive glasses. In this study, we are able to provide a new production alternative for 45S5 bioactive glass structures resulting in parts with high density and strength. Using the stereolithographic ceramic manufacturing (SLCM) process, it is possible to additively produce solid bulk glass ceramics as well as delicate scaffold structures. Recent developments in SLCM slurry preparation together with an appropriate selection of raw materials led to 3D parts with a very homogeneous microstructure and a density of about 2.7 g/cm(3). Due to the low number and small size of defects, a high biaxial bending strength of 124 MPa was achieved. Weibull distribution also underlines good process control showing a Weibull modulus of 8.6 and a characteristic strength of 131 MPa for the samples tested here. By reaching bending strength values of natural cortical bone, bioactive glasses processed with SLCM could eventually advance to be an interesting bone substitute material even in load-bearing applications, valuing the huge efforts undertaken to understand their bioactive behavior.

Sterilization effects on the physical properties and cytotoxicity of poly (glycerol sebacate) - Rai, Ranjana; Tallawi, Marwa; Roether, Judith; Detsch, Rainer; Barbani, Niccoletta; Rosellini, Elisabeth; Kaschta, Joachim; Schubert, Dirk W.; Boccaccini, Aldo R. (Materials Letters, 2013)
The influence of conventional sterilization methods such as gamma irradiation, ethylene oxide treatment and steam exposure on the physical properties of poly(glycerol sebacate) (PGS) was investigated. Scanning electron microscope (SEM) observations, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and Raman spectra demonstrated that the applied sterilization methods do not induce adverse surface modifications. The sterilized samples also maintained their thermal and mechanical properties post-sterilization. In addition, gamma sterilized PGS films did not induce any toxicity when films were in contact with murine fibroblast 313 cells. PGS is compatible for all the sterilization methods used in this study, which is of relevance for the wider application of PGS in medical devices. (C) 2013 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.steril
Keywords: Biocompatibility; Biopolymers; Gamma irradiation; Poly(glycerol sebacate); Sterilization

Stiffness Improvement of 45S5 Bioglass®-Based Scaffolds Through Natural and Synthetic Biopolymer Coatings: An Ultrasonic Study - Hum, Jasmin; Luczynski, K. W.; Nooeaid, Patcharakamon; Newby, P.; Lahayne, O.; Hellmich, C.; Boccaccini, Aldo R. (Strain, 2013)
Due to its excellent bioactivity, 45S5 Bioglass® is being highly considered in tissue engineering scaffold development. In order to enhance vascularization promoting tissue growth, these scaffolds typically have a highly interconnected porous structure with a porosity between 80 and >90%. Often, Bioglass®-based scaffolds of such a high porosity have insufficient stiffness. In order to increase the stiffness of Bioglass®-based scaffolds fabricated by the foam replica method, the herein investigated scaffolds were coated with a number of different biopolymers, including: collagen, gelatin, polycaprolactone (PCL), alginate and poly(l-lactic acid). The resulting stiffness gain was quantified by means of ultrasonic measurements. Accordingly, PCL and collagen coatings increased the scaffold stiffness, as compared to uncoated scaffolds, by 58 and 38%, respectively; while no remarkable stiffness increase was recorded for the other coatings. Additionally, scanning electron microscopy images of polymer coated scaffolds revealed that PCL coatings had not clogged the scaffold's micropores, which is deemed essential for cell seeding and to enable in-growth of bone tissue. Thus, the application of PCL coatings represents a promising strategy for mechanical competence enhancement of Bioglass®-based scaffolds for bone tissue engineering. © 2013 Wiley Publishing Ltd.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.stiffn
Keywords: Bioglass®; elasticity; polymer coating; tissue engineering scaffold; ultrasound

Stiffness improvement of 45s5 bioglass®-based scaffolds through pcl and collagen coatings: An ultrasonic study - Hum, Jasmin; Luczynski, Krzysztof W.; Nooeaid, Patcharakamon; Newby, Pippa; Lahayne, Olaf; Hellmich, Christian; Boccaccini, Aldo R. (30th DANUBlA-ADRIA Symposium on Advances in Experimental Mechanics, DAS 2013 - Proceedings, 2013)
CRIS-Team Scopus Importer:2022-08-05

Strategies for the chemical and biological functionalization of scaffolds for cardiac tissue engineering: A review - Tallawi, Marwa; Rosellini, Elisabetta; Barbani, Niccoletta; Cascone, Maria Grazia; Rai, Ranjana; Saint-Pierre, Guillaume; Boccaccini, Aldo R. (Journal of the Royal Society Interface, 2015)
The development of biomaterials for cardiac tissue engineering (CTE) is challenging, primarily owing to the requirement of achieving a surface with favourable characteristics that enhances cell attachment and maturation. The biomaterial surface plays a crucial role as it forms the interface between the scaffold (or cardiac patch) and the cells. In the field of CTE, synthetic polymers (polyglycerol sebacate, polyethylene glycol, polyglycolic acid, poly-L-lactide, polyvinyl alcohol, polycaprolactone, polyurethanes and poly(N-isopropylacrylamide)) have been proven to exhibit suitable biodegradable and mechanical properties. Despite the fact that they show the required biocompatible behaviour, most synthetic polymers exhibit poor cell attachment capability. These synthetic polymers are mostly hydrophobic and lack cell recognition sites, limiting their application. Therefore, biofunctionalization of these biomaterials to enhance cell attachment and cell material interaction is being widely investigated. There are numerous approaches for functionalizing a material, which can be classified as mechanical, physical, chemical and biological. In this review, recent studies reported in the literature to functionalize scaffolds in the context of CTE, are discussed. Surface, morphological, chemical and biological modifications are introduced and the results of novel promising strategies and techniques are discussed.
Keywords: Biofunctionalization; Biological modification; Biomimetic scaffolds; Cardiac tissue engineering; Chemical modification

Stratified scaffolds for osteochondral tissue engineering applications: Electrospun PDLLA nanofibre coated Bioglass®-derived foams - Yunos, D. M.; Ahmad, Z.; Salih, V.; Boccaccini, Aldo R. (Journal of Biomaterials Applications, 2013)
This work focuses on designing bilayered constructs by combining electrospun poly-DL-Lactide (PDLLA) fibers and Bioglass®-derived scaffolds for development of osteochondral tissue replacement materials. Electrospinning was carried out using a solution of 5 wt/v% PDLLA in dimethyl carbonate. The PDLLA layer thickness increased from 2 to 150 μm with varying electrospinning time. Bioactivity studies in simulated body fluid showed that HA mineralization decreased as the thickness of the PDLLA layer increased. A preliminary in vitro study using chondrocyte cells (ATDC5) showed that cells attached, proliferated and migrated into the fibrous network, confirming the potential applicability of the bilayered scaffolds in osteochondral defect regeneration. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.strati
Keywords: Bioactive glass; composites; osteochondral tissue engineering; scaffolds

Stratified scaffolds for osteochondral tissue engineering - Nooeaid, Patcharakamon; Schulze-Tanzil, Gundula; Boccaccini, Aldo R. (Cartilage Tissue Engineering, 2015)
Stratified scaffolds are promising devices finding application in the field of osteochondral tissue engineering. In this scaffold type, different biomaterials are chosen to fulfill specific features required to mimic the complex osteochondral tissue interface, including cartilage, interlayer tissue, and subchondral bone. Here, the biomaterials and fabrication methods currently used to manufacture stratified multilayered scaffolds as well as cell seeding techniques for their characterization are presented
Keywords: Alginate; Biomaterial; Mesenchymal stem cells; Osteochondral tissue engineering; Stratified scaffold

Strengthening mechanism of PDLLA coated titania foam - Fiedler, Thomas; Fisher, M.; Roether, Judith; Belova, I. V.; Samtleben, T.; Bernthaler, T.; Murch, G. E.; Boccaccini, Aldo R. (Mechanics of Materials, 2014)
This paper addresses the numerical analysis of the mechanical properties of titania foam intended for use in tissue engineering scaffolds. Special focus is given to a PDLLA coating that has been shown to distinctly increase the mechanical strength of the scaffold. Micro-computed tomography (μCT) data of a real scaffold are obtained and converted into numerical calculation models. Finite element simulations are performed alternately with and without the PDLLA coating. In addition, a strut model containing a single micro-crack is analysed. Numerical results indicate that filling the crack with PDLLA significantly increases the strength of the strut by attenuating stress concentrations. © 2013 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2014.tech.IW.LM.streng
Keywords: Biomaterial; Composite material; Finite element analysis; Micro-computed tomography; Micro-structure

Strengthening of dental adhesives via particle reinforcement - Belli, Renan; Kreppel, Stefan; Petschelt, Anselm; Hornberger, Helga; Boccaccini, Aldo R.; Lohbauer, Ulrich (Journal of the Mechanical Behavior of Biomedical Materials, 2014)
The bond between methacrylic polymer adhesives and dental restoratives is not perfect and may fail either in the short or in the long term. This study aims to evaluate the effects of particle incorporation in a self-etch model adhesive on mechanical and physical properties that are relevant during application and service. Filled adhesives containing 5, 10, 15 or 25. wt% glass fillers were compared to their unfilled counterpart in terms of water sorption and solubility; viscosity and dynamic viscosity during polymerization were recorded using rheological measurements and compared to FTIR analysis of the real-time degree of cure. Elastic modulus and ultimate tensile strength measurements were performed in uniaxial tension; the energy to fracture was used to calculate the fracture toughness of the adhesives. Finally, the experimental adhesives were applied on dentin substrate to test the bond strength using the microtensile test. Results showed that the incorporation of 5-10. wt% nanofiller to self-etching dental adhesives is efficient in accelerating the polymerization reaction and increasing the degree of cure without compromising the film viscosity for good wettability or water sorption and solubility. Fillers increased the elastic modulus, tensile strength and fracture toughness to a plateau between 5 and 15. wt% filler concentration, and despite the tendency to form agglomerations, active crack pinning/deflection toughening mechanisms have been observed. The bond strength between resin composite and dentin was also improved when adhesives with up to 10. wt% fillers were used, with no additional improvements with further packing. The use of fillers to reinforce dental adhesives may therefore be of great practical benefit by improving curing and mechanical properties. © 2014 Elsevier Ltd.
Keywords: Adhesives; Bond strength; Dentin; Elasticity; Nanoparticles

Stress relaxation amplitude of hydrogels determines migration, proliferation, and morphology of cells in 3-D culture - Hazur, Jonas; Endrizzi, Nadine; Schubert, Dirk W.; Boccaccini, Aldo R.; Fabry, Ben (Biomaterials Science, 2021)
The viscoelastic behavior of hydrogel matrices sensitively influences the cell behavior in 3-D culture and biofabricated tissue model systems. Previous reports have demonstrated that cells tend to adhere, spread, migrate and proliferate better in hydrogels with pronounced stress relaxation. However, it is currently unknown if cells respond more sensitively to the amplitude of stress relaxation, or to the relaxation time constant. To test this, we compare the behavior of fibroblasts cultured for up to 10 days in alginate and oxidized alginate hydrogels with similar Young's moduli but diverging stress relaxation behavior. We find that fibroblasts elongate, migrate and proliferate better in hydrogels that display a higher stress relaxation amplitude. By contrast, the cells' response to the relaxation time constant was less pronounced and less consistent. Together, these data suggest that it is foremost the stress relaxation amplitude of the matrix that determines the ability of cells to locally penetrate and structurally remodel the matrix on a molecular level, which subsequently leads to better spreading, faster migration, and higher cell proliferation. We conclude that the stress relaxation amplitude is a central design parameter for optimizing cell behavior in 3-D hydrogels.
CRIS-Team WoS Importer:2021-12-10

Structural characterization and evaluation of antibacterial and angiogenic potential of gallium-containing melt-derived and gel-derived glasses from CaO-SiO2 system - Wajda, Aleksandra; Goldmann, Wolfgang; Detsch, Rainer; Grünewald, Alina; Boccaccini, Aldo R.; Sitarz, Maciej (Ceramics International, 2018)
Keywords: Angiogenesis; Antibacterial properties; Gallium oxide; Bioactive silicate glasses; Biocompatibility

Structure optimisation and biological evaluation of bone scaffolds prepared by co-sintering of silicate and phosphate glasses - Novajra, G.; Perdika, P.; Pisano, R.; Miola, M.; Bari, A.; Jones, J. R.; Detsch, Rainer; Boccaccini, Aldo R.; Vitale-Brovarone, C. (Advances in Applied Ceramics, 2015)
A degradable phosphate glass (ICEL) and a bioactive silicate glass (CEL2) were mixed in different ratios (wt-%: 100% ICEL, 70% ICEL-30% CEL2, 30% ICEL-70% CEL2, 100% CEL2; codes 100-0, 70-30, 30-70, 0-100) and then co-sintered to obtain three-dimensional porous scaffolds by gel casting foaming. Thermal analyses were carried out on the glass mixtures and were used as a starting point for the optimisation of the scaffold sintering treatment. The microcomputed tomography and field emission scanning electron microscope analyses allowed the selection of the optimal sintering temperature to obtain an adequate structure in terms of total and open porosity. The scaffolds showed an increasing solubility with increasing ICEL glass content, and for 30-70 and 0-100, the precipitation of hydroxyapatite in simulated body fluid was observed. In vitro tests indicated that all the scaffolds showed no cytotoxic effect. The co-sintering of silicate and phosphate glasses showed to be a promising strategy to tailor the scaffold osteoconductivity, degradation and bioactivity.
Keywords: Bone scaffold; Silicate glass; Phosphate glass; Co-sintering; Gel cast foaming; Microcomputed tomography; Cell test

Studies on Cell Compatibility, Antibacterial Behavior, and Zeta Potential of Ag-Containing Polydopamine-Coated Bioactive Glass-Ceramic - Tejido Rastrilla, Rocío; Ferraris, Sara; Goldmann, Wolfgang; Grünewald, Alina; Detsch, Rainer; Baldi, Giovanni; Spriano, Silvia; Boccaccini, Aldo R. (Materials, 2019)
Dopamine is a small molecule that mimics the adhesive component (L-DOPA) of marine mussels with a catecholamine structure. Dopamine can spontaneously polymerize to form polydopamine (PDA) in a mild basic environment. PDA binds, in principle, to all types of surfaces and offers a platform for post-modification of surfaces. In this work, a novel Ag-containing polydopamine coating has been developed for the functionalization of bioactive glass-ceramics. In order to study the interactions between the surface of uncoated and coated samples and the environment, we have measured the surface zeta potential. Results confirmed that PDA can interact with the substrate through different chemical groups. A strongly negative surface zeta potential was measured, which is desirable for biocompatibility. The dual function of the material, namely the capability to exhibit bioactive behavior while being antibacterial and not harmful to mammalian cells, was assessed. The biocompatibility of the samples with MG-63 (osteoblast-like) cells was determined, as well as the antibacterial behavior against Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. During cell biology tests, uncoated and PDA-coated samples showed biocompatibility, while cell viability on Ag-containing PDA-coated samples was reduced. On the other hand, antibacterial tests confirmed the strong antimicrobial properties of Ag-containing PDA-coated samples, although tailoring of the silver release will be necessary to modulate the dual effect of PDA and silver.
CRIS-Team WoS Importer:2019-03-22

Study of the electrophoretic deposition of chitosan/halloysite nanotubes/titanium dioxide composite coatings using taguchi experimental design approach - Boccaccini, Aldo R.; Seuß, Sigrid; Raddaha, Namir (Key Engineering Materials, 2015)
This study presents experimental results on the electrophoretic deposition (EPD) of chitosan/halloysite nanotube/titanium dioxide composite coatings based on the Taguchi design of experiments (DOE) approach. Taguchi array of L18 type with mixed levels of the control factor was used to study the influence of EPD parameters, including halloysite nanotubes concentration, electric voltage and deposition time, on deposition yield. For identifying the significant factors that affected the deposition yield, multivariate analysis of variance (MANOVA) and regression analysis based on partial least-square method were used. The coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analyses, respectively. It was found that the deposition time has significantly influenced the deposition rate but the halloysite nanotube concentration and the applied voltage have the smallest effect on the deposition. The optimum condition for high yield of deposition with low standard deviation is achieved when the concentration of halloysite nanotubes is 0.3g/L and the applied voltage is 40volt with 300sec. as a deposition time. The predicted EPD conditions were verified by experiments and qualitative agreement was obtained.
Keywords: Chitosan; Electrophoretic deposition; Halloysite nanotubes; Taguchi design; Titanium dioxide

Surface engineering of mesoporous bioactive glass nanoparticles with bacteriophages for enhanced antibacterial activity - Meng, Xiangjun; Xu, Zhiyan; Wang, Chen; Patitz, Jennifer; Boccaccini, Aldo R.; Burkovski, Andreas; Zheng, Kai (Colloids and Surfaces B: Biointerfaces, 2024)
Binary SiO2-CaO mesoporous bioactive glass nanoparticles (MBGNs) are multifunctional biomaterials able to promote osteogenic, angiogenic, and immunomodulatory activities. MBGNs have been applied in a variety of tissue regeneration strategies. However, MBGNs lack strong antibacterial activity and current strategies (loading of antibacterial ions or antibiotics) toward enhanced antibacterial activity may cause cytotoxicity or antibiotic resistance. Here we engineered MBGNs using bacteriophages (phages) to enhance the antibacterial activity. Salmonella Typhimurium (S. T) phage PFPV25.1 that can infect Salmonella enterica serovar Typhimurium strain LT2 was used as a model phage to engineer MBGNs. MBGNs were first modified with amine groups to enhance the affinity between phages and MBGNs surfaces. Afterward, the physicochemical and antibacterial activity of phage-engineered MBGNs was evaluated. The results showed that S. T phage PFPV25.1 was successfully bound onto MBGNs surfaces without losing their bioactivity. A higher quantity of phages could be bounded onto amine-functionalized MBGNs than onto non-functionalized MBGNs. Phages on amine-functionalized MBGNs exhibited higher antibacterial activity. The stability test showed that phages could remain on amine-functionalized MBGNs for over 28 days. This work provides valuable information on developing phage-modified MBGNs as a new and effective antibacterial system for biomedical applications.
CRIS-Team Scopus Importer:2024-01-12
Keywords: Bacterial control; Bioactive glass; Nanoparticles; Phage; Samonella Typhimurium

Surface functionalization of bioactive glasses - Boccaccini, Aldo R.; et al. (Journal of Biomedical Materials Research Part A, 2009)
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.surfac

Surface functionalization of Bioglass((R))-derived porous scaffolds - Boccaccini, Aldo R.; et al. (Acta Biomaterialia, 2007)
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.surfac

Surface functionalization of Bioglass® with alkaline phosphatase - Verne, E.; Ferraris, S.; Cassinelli, C.; Boccaccini, Aldo R. (Surface & Coatings Technology, 2015)
The possibility to graft ALP in an active state on sintered Bioglass (R) samples both via direct grafting and silanization routes has been demonstrated in the present research. ALP enhances and fastens in vitro bioactivity of the glass-ceramic. Surface functionalization of Bioglass (R) pellets is of interest as model for sintered Bioglass (R) derived scaffolds to be used in bone engineering. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Surface modification; Bioactive glasses; Enzyme(s); Smart materials; Mineralization; Bioglass (R)

Surface microstructure and chemistry of functionalised Bioglass-derived glass-ceramics - Boccaccini, Aldo R.; et al. (Glass Technology, 2007)
Cell attachment onto Bioglass-derived glass-ceramics can be improved through surface chemical treatment, such as silanisation using aminopopyl-triethoxysilane (APTS). One concern raised by this treatment is that the alkalinity of the silane could change the surface topography such that attached cells might eventually be negatively affected by the sharp ridges formed during silanisation. It is, therefore, necessary to find out an optimal treatment condition at which a monolayer of APTS forms on the glass-ceramic surface without leading to sharp features on the surface. In this work, Bioglass-derived glass-ceramics pellets were treated in an APTS solution at 80°C for 1, 2, 3, and 4 h, immediately followed by microstructural and compositional analysis. It was found that the glass matrix dissolved and crystalline particles were leached out during the surface treatment, leaving a honeycomb-like morphology on the surface. One hour treatment was sufficient for the attachment of APTS molecules, and further treatment did not increase APTS amount considerably, while sharpening the surface topography remarkably.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.surfac_6

Surface Modification of 3D-Printed PCL/BG Composite Scaffolds via Mussel-Inspired Polydopamine and Effective Antibacterial Coatings for Biomedical Applications - Ilyas, Kanwal; Akhtar, Muhammad Asim; Ammar, Ezzeddine Ben; Boccaccini, Aldo R. (Materials, 2022)
A wide variety of composite scaffolds with unique geometry, porosity and pore size can be fabricated with versatile 3D printing techniques. In this work, we fabricated 3D-printed composite scaffolds of polycaprolactone (PCL) incorporating bioactive glass (BG) particles (13-93 and 13-93B3 compositions) by using fused deposition modeling (FDM). The scaffolds were modified with a “mussel-inspired surface coating” to regulate biological properties. The chemical and surface properties of scaffolds were analyzed by Fourier transform infrared spectroscopy (FTIR), contact angle and scanning electron microscopy (SEM). Polydopamine (PDA) surface-modified composite scaffolds exhibited attractive properties. Firstly, after the surface modification, the adhesion of a composite coating based on gelatin incorporated with strontium-doped mesoporous bioactive glass (Sr-MBGNs/gelatin) was significantly improved. In addition, cell attachment and differentiation were promoted, and the antibacterial properties of the scaffolds were increased. Moreover, the bioactivity of these scaffolds was also significantly influenced: a hydroxyapatite layer formed on the scaffold surface after 3 days of immersion in SBF. Our results suggest that the promoting effect of PDA coating on PCL-BG scaffolds leads to improved scaffolds for bone tissue engineering.
CRIS-Team Scopus Importer:2022-12-23
Keywords: 3D printing; bioactive glass; composite coating; FDM; scaffolds; surface modification

Surface Modification of SPIONs in PHBV Microspheres for Biomedical Applications - Idris, Maizlinda Izwana Binti; Zaloga, Jan; Detsch, Rainer; Roether, Judith; Unterweger, Harald; Alexiou, Christoph; Boccaccini, Aldo R. (Scientific Reports, 2018)
Surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) has been introduced with lauric acid and oleic acid via co-precipitation and thermal decomposition methods, respectively. This modification is required to increase the stability of SPIONs when incorporated in hydrophobic, biodegradable and biocompatible polymers such as poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this work, the solid-in-oil-in-water (S/O/W) emulsion-solvent extraction/evaporation method was utilized to fabricate magnetic polymer microspheres incorporating SPIONs in PHBV. The prepared magnetic PHBV microspheres exhibited particle sizes <1 mu m. The presence of functional groups of lauric acid, oleic acid and iron oxide in the PHBV microspheres was confirmed by Fourier Transform Infrared spectroscopy (FTIR). X-ray diffraction (XRD) analysis was performed to further confirm the success of the combination of modified SPIONs and PHBV. Thermogravimetric analysis (TGA) indicated that PHBV microspheres were incorporated with SPIONs(Lauric) as compared with SPIONs(Oleic). This was also proven via magnetic susceptibility measurement as a higher value of this magnetic property was detected for PHBV/SPIONs(Lauric) microspheres. It was revealed that the magnetic PHBV microspheres were non-toxic when assessed with mouse embryotic fibroblast cells (MEF) at different concentrations of microspheres. These results confirmed that the fabricated magnetic PHBV microspheres are potential candidates for use in biomedical applications.
Keywords: biomedical materials; cell culture; superparamagnetic iron oxide nanoparticles

Synthesis and characterization of a collagen-based composite material containing selenium nanoparticles - Stevanović, Magdalena M.; Filipović, Nenad; Kuzmanović, Maja; Tomić, Nina; Ušjak, Dušan; Milenković, Marina; Zheng, Kai; Stampfl, Juergen; Boccaccini, Aldo R. (Journal of Biomaterials Applications, 2022)
Multidrug-resistant bacterial strains represent an emerging global health threat and a great obstacle for bone tissue engineering. One of the major components of the extracellular matrix of the bone is a collagen protein, while selenium is an element that has antimicrobial potential, and is also important for bone metabolism and bone health. Here we represent the incorporation of selenium nanoparticles (SeNPs) synthesized by the green chemical reduction method into collagen gels to produce a composite material, collagen/SeNPs, with antimicrobial properties. The samples were comprehensively characterized by zeta potential measurements, dynamic light scattering inductively coupled plasma-mass spectrometry (ICP-MS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), optical microscopy, field-emission scanning electron microscopy (FE-SEM), and differential scanning calorimetry The cytotoxicity of the SeNPS, as well as collagen/SeNPs, was tested on the MRC-5 cells. It was revealed that collagen/SeNPS expressed a lower cytotoxic effect. Collagen/SeNPs showed significant antibacterial activity against all tested Gram-positive strains, the major causative agents of orthopedic infections as well as Candida albicans. Furthermore, three-dimensional β-tricalcium phosphate (3D-TCP) scaffolds were fabricated by a well-established 3D printing (lithography) method, and afterward preliminary coated by newly-synthesized SeNPs or collagen/SeNPs. In addition, uncoated 3D-TCP scaffolds as well as coated by collagen/SeNPs were subjected to biofilm formation. The production of Staphylococcus aureus biofilm on coated scaffolds by collagen/SeNPs was significantly reduced compared to the uncoated ones.
CRIS-Team Scopus Importer:2022-03-18
Keywords: antimicrobial activity; biomaterials; collagen; composite materials; scaffolds; selenium nanoparticles

Synthesis and characterization of citrate-stabilized gold-coated superparamagnetic iron oxide nanoparticles for biomedical applications - Stein, René; Friedrich, Bernhard; Mühlberger, Marina; Cebulla, Nadine; Schreiber, Eveline; Tietze, Rainer; Cicha, Iwona; Alexiou, Christoph; Dutz, Silvio; Boccaccini, Aldo R.; Unterweger, Harald (Molecules, 2020)
Surface-functionalized gold-coated superparamagnetic iron oxide nanoparticles (Au-SPIONs) may be a useful tool in various biomedical applications. To obtain Au-SPIONs, gold salt was precipitated onto citrate-stabilized SPIONs (Cit-SPIONs) using a simple, aqueous one-pot technique inspired by the Turkevich method of gold nanoparticle synthesis. By the further stabilization of the Au-SPION surface with additional citrate (Cit-Au-SPIONs), controllable and reproducible Z-averages enhanced long-term dispersion stability and moderate dispersion pH values were achieved. The citrate concentration of the reaction solution and the gold/iron ratio was found to have a major influence on the particle characteristics. While the gold-coating reduced the saturation magnetization to 40.7% in comparison to pure Cit-SPIONs, the superparamagnetic behavior of Cit-Au-SPIONs was maintained. The formation of nanosized gold on the SPION surface was confirmed by X-ray diffraction measurements. Cit-Au-SPION concentrations of up to 100 µg Fe/mL for 48 h had no cytotoxic effect on Jurkat cells. At a particle concentration of 100 µg Fe/mL, Jurkat cells were found to take up Cit-Au-SPIONs after 24 h of incubation. A significantly higher attachment of thiol-containing L-cysteine to the particle surface was observed for Cit-Au-SPIONs (53%) in comparison to pure Cit-SPIONs (7%).
CRIS-Team Scopus Importer:2020-10-16
Keywords: Characterization; Cytotoxicity; Gold coating; Nanoparticles; Superparamagnetic iron oxide nanoparticles (SPIONs); Surface functionalization; Thiol-binding

Synthesis and characterization of innovative resveratrol nanobelt-like particles and assessment of their bioactivity, antioxidative and antibacterial properties - Tomić, Nina; Matić, Tamara; Filipović, Nenad; Mitić Ćulafić, Dragana; Boccaccini, Aldo R.; Stevanović, Magdalena M. (Journal of Biomaterials Applications, 2023)
Recently, many studies have shown various beneficial effects of polyphenol resveratrol (Res) on human health. The most important of these effects include cardioprotective, neuroprotective, anti-cancer, anti-inflammatory, osteoinductive, and anti-microbial effects. Resveratrol has cis and trans isoforms, with the trans isoform being more stable and biologically active. Despite the results of in vitro experiments, resveratrol has limited potential for application in vivo due to its poor water solubility, sensitivity to oxygen, light, and heat, rapid metabolism, and therefore low bioavailability. The possible solution to overcome these limitations could be the synthesis of resveratrol in nanoparticle form. Accordingly, in this study, we have developed a simple, green solvent/non-solvent physicochemical method to synthesize stable, uniform, carrier-free resveratrol nanobelt-like particles (ResNPs) for applications in tissue engineering. UV–visible spectroscopy (UV-Vis) was used to identify the trans isoform of ResNPs which remained stable for at least 63 days. The additional qualitative analysis was performed by Fourier transform infrared spectroscopy (FTIR), while X-ray diffraction (XRD) determined the monoclinic structure of resveratrol with a significant difference in the intensity of diffraction peaks between commercial and nano-belt form. The morphology of ResNPs was evaluated by optical microscopy and field-emission scanning electron microscope (FE-SEM) that revealed a uniform nanobelt-like structure with an individual thickness of less than 1 μm. Bioactivity was confirmed using Artemia salina in vivo toxicity assay, while 2,2–diphenyl-1-picrylhydrazylhydrate (DPPH) reduction assay showed the good antioxidative potential of concentrations of 100 μg/ml and lower. Microdilution assay on several reference strains and clinical isolates showed promising antibacterial potential on Staphylococci, with minimal inhibitory concentration (MIC) being 800 μg/ml. Bioactive glass-based scaffolds were coated with ResNPs and characterized to confirm coating potential. All of the above make these particles a promising bioactive, easy-to-handle component in various biomaterial formulations.
CRIS-Team Scopus Importer:2023-07-07
Keywords: antibacterial activity; antioxidative activity; bioactivity assay; nanoparticles; Resveratrol

Synthesis and characterization of manganese containing mesoporous bioactive glass nanoparticles for biomedical applications - Nawaz, Qaisar; Ur Rehman, Muhammad Atiq; Burkovski, Andreas; Schmidt, Jochen; Beltran, Ana M.; Shahid, Ameen; Alber, Nina K.; Peukert, Wolfgang; Boccaccini, Aldo R. (Journal of Materials Science: Materials in Medicine, 2018)
Mesoporous bioactive glass (BG) nanoparticles based in the system: SiO2-P2O5-CaO-MnO were synthesized via a modified Stober process at various concentrations of Mn (0-7 mol %). The synthesized manganese-doped BG nanoparticles were characterized in terms of morphology, composition, in vitro bioactivity and antibacterial activity. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis confirmed that the particles had spherical morphology (mean particle size: 110 nm) with disordered mesoporous structure. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Mn, Ca, Si and P in the synthesized Mn-doped BG particles. Moreover, X-ray diffraction (XRD) analysis showed that Mn has been incorporated in the amorphous silica network (bioactive glass). Moreover, it was found that manganese-doped BG particles form apatite crystals upon immersion in simulated body fluid (SBF). Inductively coupled plasma atomic emission spectroscopy (ICP-OES) measurements confirmed that Mn is released in a sustained manner, which provided antibacterial effect against Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. The results indicate that the incorporation of Mn in the bioactive glass network is an effective strategy to develop novel multifunctional BG nanoparticles for bone tissue engineering.

Synthesis and characterization of manganese containing mesoporous bioactive glass nanoparticles for biomedical applications - Nawaz, Qaisar; Ur Rehman, Muhammad Atiq; Burkovski, Andreas; Schmidt, Jochen; Shahid, Ameen; Peukert, Wolfgang; Boccaccini, Aldo R. (Journal of Materials Science: Materials in Medicine, 2018)
Mesoporous bioactive glass (BG) nanoparticles based in the system: SiO2–P2O5-CaO-MnO were synthesized via a modified Stöber process at various concentrations of Mn (0-7 mol%). The synthesized manganese-doped BG nanoparticles were characterized in terms of morphology, composition, in vitro bioactivity and antibacterial activity. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis confirmed that the particles had spherical morphology (mean particle size: 110 nm) with disordered mesoporous structure. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of Mn, Ca, Si and P in the synthesized Mn-doped BG particles. Moreover, X-ray diffraction (XRD) analysis has shown that Mn has been incorporated into the amorphous silica network (bioactive glass). More over, it was found that manganese-doped BG particles form apatite crystals upon being immersed in simulated body fluid (SBF). Inductively coupled plasma atomic emission spectroscopy (ICP-OES) measurements confirmed that Mn is released in a sustained mannerBacillus subtilis , Pseudomonas aeruginosaaeruginosa Staphylococcus aureus . The multifunctional BG nanoparticles for bone tissue engineering. The results indicate that the incorporation of Mn into the bioactive glass network is effective. and <br

Synthesis and characterization of rubidium-containing bioactive glass nanoparticles - Ouyang, Sihui; Zheng, Kai; Huang, Qianli; Liu, Yong; Boccaccini, Aldo R. (Materials Letters, 2020)
Developing bioactive glass nanoparticles (BGNs) comprising biologically active ions is a promising strategy to enhance therapeutic performance. Given the pro-osteogenic activity of rubidium (Rb), a new type of Rb-containing BGNs was developed in this work. Here, a modified Stӧber method was employed to synthesize monodispersed spherical BGNs (particle size 100 nm) with different contents of Rb incorporation (nominal 1, 3 and 5 at.%). The results showed that Rb incorporation did not significantly affect the size, shape and amorphous characteristic of BGNs. The real Rb contents (maximum 0.62 at.%) in BGNs were much lower than the designed ones. Compared with Rb-free BGNs, Rb-BGNs exhibited enhanced hydroxyapatite-forming ability in simulated body fluid. The results suggest that Rb-BGNs are promising to be used as bioactive fillers for bone regeneration applications.
CRIS-Team Scopus Importer:2020-06-02
Keywords: Bioceramics; Bone regeneration; Nanoparticles; Rubidium; Sol-gel preparation

Synthesis and characterization of silver-doped mesoporous bioactive glass and its applications in conjunction with electrospinning - Ciraldo, Francesca; Liverani, Liliana; Gritsch, Lukas; Goldmann, Wolfgang; Boccaccini, Aldo R. (Materials, 2018)
Keywords: Bioactive glass; Antimicrobial; Ordered mesoporous glass; Electrospinning; Silver; Scaffolds

Synthesis and characterization of tissue plasminogen activator—functionalized superparamagnetic iron oxide nanoparticles for targeted fibrin clot dissolution - Heid, Susanne; Unterweger, Harald; Tietze, Rainer; Friedrich, Ralf P.; Weigel, Bianca; Cicha, Iwona; Eberbeck, Dietmar; Boccaccini, Aldo R.; Alexiou, Christoph; Lyer, Stefan (International Journal of Molecular Sciences, 2017)
Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted great attention in many biomedical fields and are used in preclinical/experimental drug delivery, hyperthermia and medical imaging. In this study, biocompatible magnetite drug carriers, stabilized by a dextran shell, were developed to carry tissue plasminogen activator (tPA) for targeted thrombolysis under an external magnetic field. Different concentrations of active tPA were immobilized on carboxylated nanoparticles through carbodiimide-mediated amide bond formation. Evidence for successful functionalization of SPIONs with carboxyl groups was shown by Fourier transform infrared spectroscopy. Surface properties after tPA immobilization were altered as demonstrated by dynamic light scattering and ζ potential measurements. The enzyme activity of SPION-bound tPA was determined by digestion of fibrin-containing agarose gels and corresponded to about 74% of free tPA activity. Particles were stored for three weeks before a slight decrease in activity was observed. tPA-loaded SPIONs were navigated into thrombus-mimicking gels by external magnets, proving effective drug targeting without losing the protein. Furthermore, all synthesized types of nanoparticles were well tolerated in cell culture experiments with human umbilical vein endothelial cells, indicating their potential utility for future therapeutic applications in thromboembolic diseases.
Keywords: Activated ester reaction; Drug targeting; Fibrinolysis; Protein binding; Superparamagnetic iron oxide nanoparticles; Tissue plasminogen activator

Synthesis and Degradation of Agar-Carbomer Based Hydrogels for Tissue Engineering Applications - Boccaccini, Aldo R.; et al. (Journal of Applied Polymer Science, 2011)
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.synthe

Synthesis and in vitro activity assessment of novel silicon oxycarbide-based bioactive glasses - Gonzalo-Juan, Isabel; Detsch, Rainer; Mathur, Sanjay; Ionescu, Emanuel; Boccaccini, Aldo R.; Riedel, Ralf (Materials, 2016)
Keywords: Bioactive glass; Bioactivity; Ca- and Mg-modified silicon oxycarbide; Cytotoxicity; Polymeric single source precursors; SiOC

Synthesis, characterization, antibacterial properties, and in vitro studies of selenium and strontium co-substituted hydroxyapatite - Maqbool, Muhammad; Nawaz, Qaisar; Ur Rehman, Muhammad Atiq; Cresswell, Mark; Jackson, Phil; Hurle, Katrin; Detsch, Rainer; Goldmann, Wolfgang; Shah, Asma Tufail; Boccaccini, Aldo R. (International Journal of Molecular Sciences, 2021)
In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO32−) in HA, strontium (Sr2+) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. Xray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.
CRIS-Team Scopus Importer:2021-04-30
Keywords: Antibacterial; Co-substituted hydroxyapatite; Cytocompatibility; Selenium; Strontium

Synthesis, Morphology and Thermal Properties of Electrospun PHB/PCL/Silica Hybrid Fibermats with and without Calcium Addition - Ding, Yaping; Roether, Judith; Schubert, Dirk W.; Boccaccini, Aldo R. (13th Bayreuth Polymer Symposium, Bayreuth, 2013)

Synthesis of copper-containing bioactive glass nanoparticles using a modified Stöber method for biomedical applications - Zheng, Kai; Dai, Xinyi; Lu, Miao; Hueser, Norbert; Taccardi, Nicola; Boccaccini, Aldo R. (Colloids and Surfaces B-Biointerfaces, 2017)
Keywords: Apatite formation; Bioactive glass nanoparticles; Copper; Ion release; Stöber method

Synthesis of monodispersed Ag-doped bioactive glass nanoparticles via surface modification - Kozon, Dominika; Zheng, Kai; Boccardi, Elena; Liu, Yufang; Liverani, Liliana; Boccaccini, Aldo R. (Materials, 2016)
Keywords: Antibacterial activity; Bioactive glass nanoparticle; Bioactivity; Silver; Surface modification

Synthesis of solgel titania bactericide coatings on adobe brick - Calabria A, Juliana; Vasconcelos, Wander L.; Daniel, Doni J.; Chater, Richard; Mcphail, David S.; Boccaccini, Aldo R. (Construction and Building Materials, 2010)
This study presents the development and characterisation of transparent sol-gel TiO2 coatings based on titanium IV isopropoxide (TIP4), formed on a sustainable clay brick material (adobe). The sol-gel layers modified the surface of adobe, which can potentially lead to new functionalities enhancing adobe performance, e.g. higher water resistance and imparting bactericidal behaviour. X-ray diffraction results on synthesised TiO2 layers based on TIP4 showed that the film has characteristic peaks of anatase phase. Static SIMS analysis was used to detect the presence of TiO2 on adobe surfaces, which were also observed by TEM confirming their thickness to be in the range 20-50 nm. Sol-gel double SiO2-TiO2 layers were also deposited on adobe substrates. These coatings did not exhibit any cracks neither signs of peeling off from the substrate. The developed surface modified adobe bricks are attractive sustainable building materials. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.synthe
Keywords: Adobe brick; Bactericide; Coatings; Sol-gel; Sustainable materials; Titania

Synthesis, properties and biomedical applications of poly(glycerol sebacate) (PGS): A review - Rai, Ranjana; Tallawi, Marwa; Grigore, Alexandra; Boccaccini, Aldo R. (Progress in Polymer Science, 2012)
Poly(glycerol sebacate) (PGS) is a biodegradable polymer increasingly used in a variety of biomedical applications. This polyester is prepared by polycondensation of glycerol and sebacic acid. PGS exhibits biocompatibility and biodegradability, both highly relevant properties in biomedical applications. PGS also involves cost effective production with the possibility of up scaling to industrial production. In addition, the mechanical properties and degradation kinetics of PGS can be tailored to match the requirements of intended applications by controlling curing time, curing temperature, reactants concentration and the degree of acrylation in acrylated PGS. Because of the flexible and elastomeric nature of PGS, its biomedical applications have mainly targeted soft tissue replacement and the engineering of soft tissues, such as cardiac muscle, blood, nerve, cartilage and retina. However, applications of PGS are being expanded to include drug delivery, tissue adhesive and hard tissue (i.e., bone) regeneration. The design and fabrication of PGS based devices for applications that mimic native physiological conditions are also being pursued. Novel designs range from accordion-like honeycomb structures for cardiac patches, gecko-like surfaces for tissue adhesives to PGS (nano) fibers for extra cellular matrix (ECM) like constructs; new design avenues are being investigated to meet the ever growing demand for replacement tissues and organs. In less than a decade PGS has become a material of great scrutiny and interest by the biomedical research community. In this review we consolidate the valuable existing knowledge in the fields of synthesis, properties and biomedical applications of PGS and PGS-related biomaterials and devices. © 2012 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.synthe
Keywords: Biocompatible; Bioresorbable polymers; PGS processing; Poly(glycerol sebacate); Tissue engineering

Systematically designed periodic electrophoretic deposition for decorating 3D carbon-based scaffolds with bioactive nanoparticles - Taale, Mohammadreza; Krüger, Diana; Ossei-Wusu, Emmanuel; Schütt, Fabian; Ur Rehman, Muhammad Atiq; Mishra, Yogendra Kumar; Marx, Janik; Stock, Norbert; Fiedler, Bodo; Boccaccini, Aldo R.; Willumeit-Römer, Regine; Adelung, Rainer; et al. (ACS Biomaterials Science and Engineering, 2019)
The coating of porous scaffolds with nanoparticles is crucial in many applications, for example to generate scaffolds for catalysis or to make scaffolds bioactive. A standard and well-established method for coating surfaces with charged nanoparticles is electrophoresis, but when used on porous scaffolds, this method often leads to a blockage of the pores so that only the outermost layers of the scaffolds are coated. In this study, the electrophoretic coating process is monitored in situ and the kinetics of nanoparticle deposition are investigated. This concept can be extended to design a periodic electrophoretic deposition (PEPD) strategy, thus avoiding the typical blockage of surface pores. In the present work we demonstrate successful and homogeneous electrophoretic deposition of hydroxyapatite nanoparticles (HAn, diameter ≤200 nm) on a fibrous graphitic 3D structure (ultralightweight aerographite) using the PEPD strategy. The microfilaments of the resulting scaffold are covered with HAn both internally and on the surface. Furthermore, protein adsorption assays and cell proliferation assays were carried out and revealed that the HAn-decorated aerographite scaffolds are biocompatible. The HAn decoration of the scaffolds also significantly increases the alkaline phosphatase activity of osteoblast cells, showing that the scaffolds are able to promote their osteoblastic activity.
CRIS-Team Scopus Importer:2019-08-23
Keywords: 3D scaffold; aerographite; electrophoretic deposition; hydroxyapatite; osteoblasts; tissue engineering

Tackling bioactive glass excessive in vitro bioreactivity: Preconditioning approaches for cell culture tests - Ciraldo, Francesca; Boccardi, Elena; Melli, Virginia; Westhauser, Fabian; Boccaccini, Aldo R. (Acta Biomaterialia, 2018)
Keywords: Cell culture; In vitro; Bioactive glasses; Bioactivity; pH

Tackling Mg alloy corrosion by natural polymer coatings - A review - Heise, Svenja; Virtanen, Sannakaisa; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2016)
The field of protective coatings for magnesium and its alloys (e.g., AZ31) using natural polymers is reviewed. Polymers utilized are broadly divided into polysaccharides and proteins. For both polymer classes examples are given focusing on coating processing and characterization. Several analysing methods reported in literature are summarized highlighting the different characterization approaches applied in different studies, which makes difficult a direct comparison of the outcomes. In most cases, the protective behavior of coatings was determined using electrochemical impedance spectroscopy or by assessing hydrogen evolution in different fluids. Mechanical tests and in vitro cell culture studies have been also carried out on selected coating systems. Overall, the results show the possibility of applying protective coat- ings based on natural polymers on magnesium and its alloys, however, in vivo investigations are scarce so that long-term results in relevant conditions are not yet available. A compar- ison with the use of synthetic polymers is presented and cur- rent challenges and areas for future research are discussed, highlighting the need for further investigations in the field, which should enable broadening the applications of Mg and Mg alloys in medicine.
Keywords: magnesium alloys; biodegradable material; natural polymers; coatings; corrosion resistance

Taguchi Design of Experiments approach to determine process parameter for the electrophoretic deposition of chitosan/bioactive glass on Mg alloy substrates - Heise, Svenja; Virtanen, Sannakaisa; Boccaccini, Aldo R. (ECS Transactions, 2018)
Bioactive glass/chitosan composite coatings were successfully deposited on a Mg alloy (WE43) by electrophoretic deposition (EPD). A Taguchi Design of Experiments approach was employed to optimize the deposition parameters (time and voltage) and the roughness of the sample, which influence the final morphology of the coating. The surface coverage was taken as target function and evaluated with a point counting method. The optimized parameters fulfil the prediction; however, a second coating layer is still needed due to the corrosive nature of the magnesium substrate. This second layer is needed to close all pores, giving a defect free coating surface.

Tailorable mechanical and degradation properties of KCl-reticulated and BDDE-crosslinked PCL/chitosan/κ-carrageenan electrospun fibers for biomedical applications: Effect of the crosslinking-reticulation synergy - Vargas-Osorio, Zulema; González Castillo, Eduin I.; Mutlu, Nurshen; Vidomanová, Eva; Michálek, Martin; Galusek, Dušan; Boccaccini, Aldo R. (International Journal of Biological Macromolecules, 2024)
The development of intricated and interconnected porous mats is desired for many applications in biomedicine and other relevant fields. The mats that comprise the use of natural, bioactive, and biodegradable polymers are the focus of current research activities. In the present work, crosslinked fibers with improved characteristics were produced by incorporating 1,4-butanediol diglycidyl ether (BDDE) into a polymer formulation containing polycaprolactone (PCL), chitosan (CS), and κappa-carrageenan (κ-C). A slight variation of formic acid (FA)/acetic acid (AA) ratio used as a solvent system, significantly affected the characteristics of the produced fiber mats. Both polysaccharides and BDDE played a major role in tailoring mechanical properties when fibrous scaffolds were reticulated under KCl-mediated basic conditions for determined periods of time at 50 °C. In vitro biological assessment of the electrospun fiber mats revealed proliferation of MC3T3-E1 cells when incubated for 1 and 7 days. After staining the cells with 4′,6-diamidino-2-phenylindole (DAPI)/rhodamine phalloidin an autofluorescence response was observed by fluorescence microscopy in the scaffold manufactured using a solvent with higher FA/AA ratio due to the formation of microfibers. The results demonstrated the potential of the BDDE-crosslinked PCL/CS/κ-C electrospun fibers as promising materials for biomedical applications that may include soft and bone tissue regeneration.
CRIS-Team Scopus Importer:2024-04-05
Keywords: BDDE crosslinking agent; Crosslinked electrospun fibers; PCL/chitosan; Reticulation with KCl; κ-Carrageenan

Tailoring elastic properties of PLGA/TiO2 biomaterials - Fiedler, Thomas; Belova, I. V.; Murch, G. E.; Roether, Judith; Boccaccini, Aldo R. (Computational Materials Science, 2012)
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.tailor

Tailoring the adhesion of electrophoretic chitosan/bioactive glass coatings by the combined surface pre-treatments of Ti substrates - Kowalczyk, Agnieszka; Sotniczuk, Agata; Kuczyńska-Zemła, Donata; Pura, Jarosław; Xu, Zhiyan; Boccaccini, Aldo R.; Garbacz, Halina (Surface & Coatings Technology, 2024)
Composite chitosan/bioactive glass coatings developed by electrophoretic deposition (EPD) attract researchers' attention owing to their advantageous effect on the biological and corrosion responses of commonly used biomedical materials. However, fabricating a uniform coating with satisfactory adhesion to the biomaterials substrate is challenging, because chitosan and bioglass particles having different mobilities during the EPD process. Typically, attempts are made to improve adhesion by manipulating the EPD parameters. This work presents an alternative approach that involves combined mechanical and chemical pre-treatments of the Ti substrate. The surface pre-treatment procedure included shot peening and the following variants of acid etching: (i) HF etching, (ii) NaOH etching, and (iii) HF and NaOH etching. Shot peening followed by etching in HF and NaOH significantly improved the adhesion of the EPD coating. It was found that this effect was due to the development of a highly hydrophilic surface with micro- and nano-scale roughness.
CRIS-Team Scopus Importer:2024-04-05
Keywords: Bioactive glass; Chitosan; Electrophoretic deposition; Surface topography; Titanium

Tailoring the surface characteristics of electrophoretically deposited chitosan-based bioactive glass composite coatings on titanium implants via grit blasting - Avcu, Egemen; Yıldıran Avcu, Yasemin; Baştan, Fatih Erdem; Ur Rehman, Muhammad Atiq; Üstel, Fatih; Boccaccini, Aldo R. (Progress in Organic Coatings, 2018)
Keywords: Electrophoretic deposition; Grit blasting; Bioactive glass; Chitosan; Surface topography; Wettability

Taking a deep look: modern microscopy technologies to optimize the design and functionality of biocompatible scaffolds for tissue engineering in regenerative medicine - Vielreicher, Martin; Schürmann, Sebastian; Detsch, Rainer; Schmidt, Miriam; Buttgereit, Andreas; Boccaccini, Aldo R.; Friedrich, Oliver (Journal of the Royal Society Interface, 2013)
This review focuses on modern nonlinear optical microscopy (NLOM) methods that are increasingly being used in the field of tissue engineering (TE) to image tissue non-invasively and without labelling in depths unreached by conventional microscopy techniques. With NLOM techniques, biomaterial matrices, cultured cells and their produced extracellular matrix may be visualized with high resolution. After introducing classical imaging methodologies such as mCT, MRI, optical coherence tomography, electron microscopy and conventional microscopy two-photon fluorescence (2-PF) and second harmonic generation (SHG) imaging are described in detail (principle, power, limitations) together with their most widely used TE applications. Besides our own cell encapsulation, cell printing and collagen scaffolding systems and their NLOM imaging the most current research articles will be reviewed. These cover imaging of autofluorescence and fluorescence-labelled tissue and biomaterial structures, SHG-based quantitative morphometry of collagen I and other proteins, imaging of vascularization and online monitoring techniques in TE. Finally, some insight is given into state-of-the-art three-photon-based imaging methods (e.g. coherent anti-Stokes Raman scattering, third harmonic generation). This review provides an overview of the powerful and constantly evolving field of multiphoton microscopy, which is a powerful and indispensable tool for the development of artificial tissues in regenerative medicine and which is likely to gain importance also as a means for general diagnostic medical imaging. © 2013 The Author(s).
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.taking
Keywords: Artificial tissues; Autofluorescence; Biomaterials; Extracellular matrix; Multiphoton imaging; Second harmonic generation

Targeted Printing of Cells: Evaluation of ADA-PEG Bioinks for Drop on Demand Approaches - Karakaya, Emine; Bider, Faina; Frank, Andreas; Teßmar, Jörg; Schöbel, Lisa; Forster, Leonard; Schrüfer, Stefan; Schmidt, Hans-Werner; Schubert, Dirk W.; Blaeser, Andreas; Boccaccini, Aldo R.; Detsch, Rainer (Gels, 2022)
A novel approach, in the context of bioprinting, is the targeted printing of a defined number of cells at desired positions in predefined locations, which thereby opens up new perspectives for life science engineering. One major challenge in this application is to realize the targeted printing of cells onto a gel substrate with high cell survival rates in advanced bioinks. For this purpose, different alginate-dialdehyde—polyethylene glycol (ADA-PEG) inks with different PEG modifications and chain lengths (1–8 kDa) were characterized to evaluate their application as bioinks for drop on demand (DoD) printing. The biochemical properties of the inks, printing process, NIH/3T3 fibroblast cell distribution within a droplet and shear forces during printing were analyzed. Finally, different hydrogels were evaluated as a printing substrate. By analysing different PEG chain lengths with covalently crosslinked and non-crosslinked ADA-PEG inks, it was shown that the influence of Schiff’s bases on the viscosity of the corresponding materials is very low. Furthermore, it was shown that longer polymer chains resulted in less stable hydrogels, leading to fast degradation rates. Several bioinks highly exhibit biocompatibility, while the calculated nozzle shear stress increased from approx. 1.3 and 2.3 kPa. Moreover, we determined the number of cells for printed droplets depending on the initial cell concentration, which is crucially needed for targeted cell printing approaches.<br
Keywords: bioprinting; drop on demand; sodium alginate; polyethylene glycol; shear stress

Technologies for Multilayered Scaffolds Suitable for Interface Tissue Engineering - Nooeaid, Patcharakamon; Roether, Judith; Weber, Eva; Schubert, Dirk W.; Boccaccini, Aldo R. (Advanced Engineering Materials, 2013)
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.techno

Tendon tissue engineering: An overview of biologics to promote tendon healing and repair - Citro, Vera; Clerici, Marta; Boccaccini, Aldo R.; Della Porta, Giovanna; Maffulli, Nicola; Forsyth, Nicholas R. (Journal of Tissue Engineering, 2023)
Tendons are dense connective tissues with a hierarchical polarized structure that respond to and adapt to the transmission of muscle contraction forces to the skeleton, enabling motion and maintaining posture. Tendon injuries, also known as tendinopathies, are becoming more common as populations age and participation in sports/leisure activities increases. The tendon has a poor ability to self-heal and regenerate given its intrinsic, constrained vascular supply and exposure to frequent, severe loading. There is a lack of understanding of the underlying pathophysiology, and it is not surprising that disorder-targeted medicines have only been partially effective at best. Recent tissue engineering approaches have emerged as a potential tool to drive tendon regeneration and healing. In this review, we investigated the physiochemical factors involved in tendon ontogeny and discussed their potential application in vitro to reproduce functional and self-renewing tendon tissue. We sought to understand whether stem cells are capable of forming tendons, how they can be directed towards the tenogenic lineage, and how their growth is regulated and monitored during the entire differentiation path. Finally, we showed recent developments in tendon tissue engineering, specifically the use of mesenchymal stem cells (MSCs), which can differentiate into tendon cells, as well as the potential role of extracellular vesicles (EVs) in tendon regeneration and their potential for use in accelerating the healing response after injury.
CRIS-Team Scopus Importer:2023-09-29
Keywords: extracellular vesicles; mesenchymal stem cells; Tendon; tissue engineering

Tetracycline-encapsulated P(3HB) microsphere-coated 45S5 Bioglass®-based scaffolds for bone tissue engineering - Meng, D.; Francis, L.; Thompson, I. D.; Mierke, Claudia; Hübner, Holger; Amtmann, A.; Roy, I.; Boccaccini, Aldo R. (Journal of Materials Science: Materials in Medicine, 2013)
Bioglass®-based scaffolds for bone tissue engineering have been developed, which can also serve as carriers for drug delivery. For this, P(3HB) microspheres (PMSs) loaded with tetracycline were fabricated and immobilised on the scaffold surfaces by a modified slurry dipping technique. The sustained drug delivery ability in simulated body fluid was confirmed by using UV-Vis absorption spectroscopy measurements. The MTT assay using mouse fibroblast cells provided evidence that the tetracycline loaded microspheres produced in this study show limited cytotoxicity. The scaffolds developed in this work provide mechanical support, adequate 3D surface roughness, bioactivity and controlled drug delivery function, and are thus interesting candidates for bone tissue engineering applications. © 2013 Springer Science+Business Media New York.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.tetrac

The 35th anniversary of Materials Letters - Boccaccini, Aldo R.; Willoughby, Arthur (Materials Letters, 2017)

The Addition of Zinc to the ICIE16-Bioactive Glass Composition Enhances Osteogenic Differentiation and Matrix Formation of Human Bone Marrow-Derived Mesenchymal Stromal Cells - Rehder, Felix; Arango Ospina, Marcela; Decker, Simon; Saur, Merve; Kunisch, Elke; Moghaddam, Arash; Renkawitz, Tobias; Boccaccini, Aldo R.; Westhauser, Fabian (Biomimetics, 2024)
An ICIE16-bioactive glass (BG) composition (in mol%: 49.5 SiO2, 6.6 Na2O, 36.3 CaO, 1.1 P2O5, and 6.6 K2O) has demonstrated excellent in vitro cytocompatibility when cultured with human bone marrow-derived mesenchymal stromal cells (BMSCs). However, its impact on the development of an osseous extracellular matrix (ECM) is limited. Since zinc (Zn) is known to enhance ECM formation and maturation, two ICIE16-BG-based Zn-supplemented BG compositions, namely 1.5 Zn-BG and 3Zn-BG (in mol%: 49.5 SiO2, 6.6 Na2O, 34.8/33.3 CaO, 1.1 P2O5, 6.6 K2O, and 1.5/3.0 ZnO) were developed, and their influence on BMSC viability, osteogenic differentiation, and ECM formation was assessed. Compared to ICIE16-BG, the Zn-doped BGs showed improved cytocompatibility and significantly enhanced osteogenic differentiation. The expression level of the osteopontin gene was significantly higher in the presence of Zn-doped BGs. A larger increase in collagen production was observed when the BMSCs were exposed to the Zn-doped BGs compared to that of the ICIE16-BG. The calcification of the ECM was increased by all the BG compositions; however, calcification was significantly enhanced by the Zn-doped BGs in the early stages of cultivation. Zn constitutes an attractive addition to ICIE16-BG, since it improves its ability to build and calcify an ECM. Future studies should assess whether these positive properties remain in an in vivo environment.
CRIS-Team Scopus Importer:2024-02-02
Keywords: bone tissue engineering; human mesenchymal stromal cells; ICIE16-bioactive glass; osteogenic differentiation; zinc

The Department of Materials Science and Engineering at the Friedrich-Alexander-University of Erlangen-Nürnberg - Travitzky, Nahum; Boccaccini, Aldo R.; Göken, Mathias (Advanced Engineering Materials, 2020)
CRIS-Team Scopus Importer:2022-08-05

The development of bioactive glass-ceramic substrates with biocide activity - Cabal, Belen; Malpartida, Francisco; Torrecillas, Ramon; Hoppe, Alexander; Boccaccini, Aldo R.; Serafin Moya, J. (Advanced Engineering Materials, 2011)
The biocide efficiency of bioactive 45S5 Bioglass ® derived glass-ceramic substrates against common Gram positive and Gram negative bacteria, and also against yeast, is investigated in this study. The results confirm the high bactericidal capacity of this material. Inorganic coatings containing silver nanoparticles on glass-ceramic substrates are developed in order to ascertain whether the presence of silver enhances the biocide activity. It is found that a coating made of soda-glass containing silver nanoparticles does not improve the antifungal properties of the 45S5 Bioglass ® derived glass-ceramic substrates. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.thedev

The effect of borate bioactive glass on the printability of methylcellulose-manuka honey hydrogels - Schuhladen, Katharina; Bednarzig, Vera; Rembold, Nadine; Boccaccini, Aldo R. (Journal of Materials Research, 2021)
Abstract: 3D printing offers the possibility to generate complex and individualized constructs (scaffolds) for applications in tissue engineering. This is viable by using suitable inks based on advanced biomaterials. Methylcellulose (MC), a highly biocompatible biomaterial, can be combined with manuka honey (H) to fabricate a thermo-sensitive hydrogel. Besides providing favorable biological effects, H can also be used as a natural cross-linking agent. Furthermore, the addition of bioactive glass (BG) to the ink could improve its mechanical and bioactive properties. In this study, a composite based on MC as matrix incorporating H and particulate borate BG as filler, was investigated as ink for 3D printing. Besides the improvement of the inks’ printability owing to the addition of BG, the printed scaffolds exhibited suitable swelling behavior and mechanical properties. Moreover, cell biology tests demonstrated the potential of the composite for biofabrication and applications in tissue engineering, which should be further explored. Graphic abstract: [Figure not available: see fulltext.].
CRIS-Team Scopus Importer:2021-06-18
Keywords: 3D printing; Additive manufacturing; Biomaterial; Porosity

The effect of coating type on mechanical properties and controlled drug release of PCL/zein coated 45S5 bioactive glass scaffolds for bone tissue engineering - Fereshteh, Zeinab; Nooeaid, Patcharakamon; Fathi, Mohammadhossein; Bagri, Akbar; Boccaccini, Aldo R. (Materials Science and Engineering C, 2015)
A highly investigated branch of tissue engineering involves the implantation of a highly porous biomaterial scaffold populated with appropriate cells to provide a three-dimensional (3D) environment in which new tissue can grow. As a drawback, the mechanical properties of foam-like BG-based scaffolds are in general poor in terms of strength and toughness for bone tissue engineering applications. Polymer coatings have been proposed to toughen brittle scaffolds, which can be achieved by the formation of a surface coating and by impregnation of microcracks and surface pores with a suitable polymer. The Fourier transform infrared (FTIR) spectra of different scaffolds were recorded on a Nicolet 6700 FTIR spectrometer in transmittance mode in the mid infrared region. Amounts of the released drugs at specified time periods were plotted as percentage of drug released versus time. The drug release evaluation was performed using 5 samples for each time up to 14 days and obtained results were expressed as the mean values and standard deviations.

The effect of electrophoretic deposition parameters on the microstructure and adhesion of zein coatings to titanium substrates - Maciąg, Filip; Moskalewicz, Tomasz; Kowalski, Kazimierz; Łukaszczyk, Alicja; Hadzhieva, Zoya; Boccaccini, Aldo R. (Materials, 2021)
Zein coatings were obtained by electrophoretic deposition (EPD) on commercially pure titanium substrates in an as-received state and after various chemical treatments. The properties of the zein solution, zeta potential and conductivity, at varying pH values were investigated. It was found that the zein content and the ratio of water to ethanol of the solution used for EPD, as well as the process voltage value and time, significantly influence the morphology of coatings. The deposits obtained from the solution containing 150 g/L and 200 g/L of zein and 10 vol % of water and 90 vol % of ethanol, about 4–5 µm thick, were dense and homogeneous. The effect of chemical treatment of the Ti substrate surface prior to EPD on coating adhesion to the substrate was determined. The coatings showed the highest adhesion to the as-received and anodized substrates due to the presence of a thick TiO2 layer on their surfaces and the presence of specific surface features. Coated titanium substrates showed slightly lower electrochemical corrosion resistance than the uncoated one in Ringer’s solution. The coatings showed a well-developed surface topography compared to the as-received substrate, and they demonstrated hydrophilic nature. The present results provide new insights for the further development of zein-based composite coatings for biomedical engineering applications.
CRIS-Team Scopus Importer:2021-01-22
Keywords: Coating; Electrophoretic deposition; Surface topography; Titanium; Zein

The effect of interfacial bonding of calcium phosphate cements containing bio-mineralized multi-walled carbon nanotube and bovine serum albumin on the mechanical properties of calcium phosphate cements - Low, Kah Ling; Zein, Sharif Hussein Sharif; Tan, Soon Huat; Mcphail, David S.; Boccaccini, Aldo R. (Ceramics International, 2011)
The aim of this study was to investigate the effect of adding bio-mineralized hydroxyl functionalized multi-walled carbon nanotubes (MWCNTs-OH) on the compressive strength of calcium phosphate cements (CPCs). Bovine serum albumin (BSA) was also incorporated as a protein which acts as promoter of hydroxyapatite (HA) crystal growth when bounded to CPC granules. The results show that the strong interfacial bonding of CPC/MWCNTs-OH is essential to improve the mechanical properties of CPC/bio-mineralized MWCNTs-OH/BSA composite. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.theeff
Keywords: B. Composites; B. Interfaces; C. Mechanical properties; Hydroxyapatite

The effect of Si species released from bioactive glasses on cell behaviour: A quantitative review - Turner, Joel; Nandakumar, Arkhash; Anilbhai, Nikhit; Boccaccini, Aldo R.; Jones, Julian R.; Jell, Gavin (Acta Biomaterialia, 2023)
Despite over 50 years of silicate bioactive glass (SBG) research, commercial success, and 6000+ published articles, there remains a lack of understanding of how soluble silicate (Si) species released from SBGs influences cellular responses. Using a systematic approach, this article quantitatively compares the in vitro responses of cells to SBG dissolution products reported in the literature and determines if there is a Si concentration ([Si]) dependent effect on cell behaviour. Cell behavioural responses to SBGs [Si] in dissolution products included metabolic activity (reported in 52 % of articles), cell number (24 %), protein production (22 %), gene expression (22 %) and biomineralization (24 %). There was a difference in the [Si] reported to cause increased (desirable) cellular responses (median = 30.2 ppm) compared to the [Si] reported to cause decreased (undesirable) cellular responses (median = 52.0 ppm) (P ≤ 0.001). The frequency of undesirable outcomes increased with increasing [Si], with ∼3 times more negative outcomes reported above 52 ppm. We also investigated the effect of [Si] on specific cellular outcomes (e.g., metabolic activity, angiogenesis, osteogenesis),if cell type/species influenced these responses and the impact of other ions (Ca, P, Na) within the SBG dissolution media on cell behaviour. This review has, for the first time, quantitatively compared the cellular responses to SBGs from the literature, providing a quantitative overview of SBG in vitro practices and presents evidence of a range of [Si] where desirable cellular responses may be more likely (30-52 ppm). This review also demonstrates the need for greater standardisation of in vitro methodological approaches and recommends some minimum reporting standards. Statement of significance: This systematic review investigates the relationship between the concentration of Si released from Si-bioactive glasses (SBG) and in vitro cellular responses. Si releasing materials continue to be of considerable scientific, commercial, and medical interest (with 1500+ articles published in the last 3 years) but there is considerable variation in the reported biologically effective Si concentrations and on the importance of Si on cell behaviour. Despite the variation in methodological approaches, this article demonstrated statistical commonalities in the Si concentrations that cause desirable and undesirable cellular behaviours, suggesting a window where positive cellular outcomes are more likely. This review also provides a quantitative analysis of in vitro practices within the bioactive glass field and highlights the need for greater standardisation.
CRIS-Team Scopus Importer:2023-09-29
Keywords: Bioactive glasses; Cell responses; Dissolution products; Silicon; Systematic review

The effect of the particle size and the morphology of alumina powders on the processing of green bodies by elecgtrophoretic desposition - Boccaccini, Aldo R.; et al. (Journal of Materials Processing Technology, 2010)
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.theeff

The Electrophoretic Deposition of Bioglasso (R)/Carbon Nanotube composite layers for bioactive coatings - Cho, Johann; Cannio, Maria; Boccaccini, Aldo R. (International Journal of Materials & Product Technology, 2009)
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.theele

The evaluation of physical properties and in vitro cell behavior of PHB/PCL/sol-gel derived silica hybrid scaffolds and PHB/PCL/fumed silica composite scaffolds - Ding, Yaping; Yao, Qingqing; Li, Wei; Schubert, Dirk W.; Boccaccini, Aldo R.; Roether, Judith (Colloids and Surfaces B: Biointerfaces, 2015)
PHB/PCL/sol-gel derived silica hybrid scaffolds (P5S1S) and PHB/PCL/fumed silica composite scaffolds (P5S1N) with a 5:1 organic/inorganic ratio were fabricated through a combination of electrospinning and sol-gel methods and dispersion electrospinning, respectively. In contrast to the silica nanoparticle aggregates appearing on the fiber surface of P5S1N, smooth and uniform fibers were obtained for P5S1S. The fiber diameter distribution, tensile strength, thermal gravimetric analysis (TGA), and cellular behavior of both types of scaffolds were characterized and studied. The tensile strength results and TGA indicated that the interfacial interaction between the organic and the inorganic phase was enhanced in P5S1S over the nanocomposite scaffolds, and cells exhibited significantly higher alkaline phosphate activity (ALP) for P5S1S, which makes P5S1S hybrid scaffolds candidate materials for bone tissue engineering applications.
Keywords: Bone tissue engineering; Electrospinning; Hybrid; Nanoparticle; Silica; Sol-gel

The homopolymer poly(3-hydroxyoctanoate) as a matrix material for soft tissue engineering - Rai, Ranjana; Boccaccini, Aldo R.; Knowles, Jonathan C.; Mordon, Nicola; Salih, Vehid; Locke, Ian C.; Moshrefi-Torbati, M.; Keshavarz, Tajalli; Roy, Ipsita (Journal of Applied Polymer Science, 2011)
The homopolymer poly(3-hydroxyoctanoate), produced from Pseudomonas mendocina with octanoate as a carbon feed, was studied as a potential biomaterial for soft tissue engineering, that is, as a cardiac patch and as matrices for skin tissue engineering. The polymer was fabricated into neat solvent-cast films of 5 and 10 wt %. Microstructural studies revealed the films as having a smooth surface topography with a root mean square value of 0.238 μm. The films also possessed moderate hydrophilicity when compared to other monomers of the polyhydroxyalkanoate family. Stress-strain curves of the films obtained was typical of that of elastomeric polymers. This elastomeric and flexible nature of the films makes them promising candidates for the proposed applications. Biocompatibility studies with the human adult low calcium temperature keratinocytes (HaCaT) keratinocyte cell line showed that the films were able to support the attachment, differentiation, and maturation of the HaCaT cells. In vitro degradation studies over a period of 4 months showed that the water absorption and weight loss increased progressively with time for the films. The films underwent hydrolytic degradation initiated on the surface and also showed an aging effect. © 2011 Wiley Periodicals, Inc.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.thehom
Keywords: biodegradable; biopolymer; elastomer; polyester

The Impact of the Cellular Environment and Aging on Modeling Alzheimer's Disease in 3D Cell Culture Models - Hebisch, Matthias; Klostermeier, Stefanie; Wolf, Katharina; Boccaccini, Aldo R.; Wolf, Stephan; Tanzi, Rudolph E.; Kim, Doo Yeon (Advanced Science, 2023)
Creating a cellular model of Alzheimer's disease (AD) that accurately recapitulates disease pathology has been a longstanding challenge. Recent studies showed that human AD neural cells, integrated into three-dimensional (3D) hydrogel matrix, display key features of AD neuropathology. Like in the human brain, the extracellular matrix (ECM) plays a critical role in determining the rate of neuropathogenesis in hydrogel-based 3D cellular models. Aging, the greatest risk factor for AD, significantly alters brain ECM properties. Therefore, it is important to understand how age-associated changes in ECM affect accumulation of pathogenic molecules, neuroinflammation, and neurodegeneration in AD patients and in vitro models. In this review, mechanistic hypotheses is presented to address the impact of the ECM properties and their changes with aging on AD and AD-related dementias. Altered ECM characteristics in aged brains, including matrix stiffness, pore size, and composition, will contribute to disease pathogenesis by modulating the accumulation, propagation, and spreading of pathogenic molecules of AD. Emerging hydrogel-based disease models with differing ECM properties provide an exciting opportunity to study the impact of brain ECM aging on AD pathogenesis, providing novel mechanistic insights. Understanding the role of ECM aging in AD pathogenesis should also improve modeling AD in 3D hydrogel systems.
CRIS-Team Scopus Importer:2023-01-27
Keywords: Alzheimer; hydrogel; neurodegeneration; nonclassical crystallization; synthetic extracellular matrix

The influence of reagent stoichiometry on the yield and aspect ratio of acid-oxidised injection CVD-grown multi-walled carbon nanotubes - Cho, Johann; Boccaccini, Aldo R.; Shaffer, Milo S. P. (Carbon, 2012)
Injection chemical vapour deposition (ICVD) was used for the preparation of multi-walled carbon nanotubes (MWCNTs) with varying lengths and diameters. The concentration of iron injected with the feedstock is related to the resulting average MWCNT dimensions, mass yield, packing density, crystallinity, and iron content. An optimum set of conditions is identified that maintains a constant diameter during growth; higher iron injection concentrations lead to an increasing MWCNT diameter as growth proceeds. Carbon nanotubes are frequently oxidised in mixtures of concentrated nitric and sulphuric acids in order to purify, functionalise, and shorten as-synthesised materials. Here, the carbon:acid stoichiometry is systematically varied, and shown to control the yield and dimensions of the resulting oxidised MWCNTs in a predictable manner, for the various ICVD starting materials. With increasing acid content, the yield of nanotubes decreases, the fraction of oxidised debris increases, and the initial, defect-driven, cutting reaction saturates, whilst thinning reactions continue. The results provide insight into both ICVD synthesis and acid oxidation of MWCNTs, as well as a means to prepare well-dispersed samples with controlled dimensions. © 2012 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.theinf

The influence of tetracycline loading on the surface morphology and biocompatibility of films made from P(3HB) microspheres - Francis, Lydia; Meng, Decheng; Locke, Ian C.; Mordan, Nicola; Salih, Vehid; Knowles, Jonathan C.; Boccaccini, Aldo R.; Roy, Ipsita (Advanced Engineering Materials, 2010)
Tetracycline, an antibiotic used against a broad range of Gram positive and Gram negative bacteria was encapsulated in microspheres made of poly(3-hydroxybutyric acid) P(3HB), a microbial biodegradable polymer isolated from Bacillus cereus SPV. The drug loaded microspheres were prepared using an oil emulsion technique and compressed uniaxially to produce films. Although the same fabrication conditions were used for preparing the drug loaded and unloaded microspheres, the presence of the drug changed the surface morphology and roughness of the films. The surface morphology of the drug loaded films appeared uneven and coarser and the roughness, with an average root mean square value of 5.89mm, was significantly higher than that of the unloaded film. The in vitro biocompatibility of the films was investigated using a human keratinocyte cell line (HaCaT) by comparing cell viability on the films to that on conventional tissue culture plastics. Both films appear to support cell growth but cell attachment and percentage cell viability were greater on the drug loaded films (32% of control) compared to the unloaded film (10% of control), possibly as a result of the non-uniform surface morphology and increased roughness of the drug loaded film. Thus, the above results illustrate that the drug loaded films, in addition to being a suitable matrix for drug delivery, represent an improved substrate for keratinocyte cell attachment. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.theinf

The Mechanical, Thermal, and Chemical Properties of PLA-Mg Filaments Produced via a Colloidal Route for Fused-Filament Fabrication - Orellana-Barrasa, Jaime; Ferrandez-Montero, Ana; Boccaccini, Aldo R.; Ferrari, Begona; Ygnacio Pastor, Jose (Polymers, 2022)
The effect of Mg particles on the thermal, chemical, physical, and primarily mechanical properties of 3D-printed PLA/Mg composites is studied in this paper. Recently, new colloidal processing has been proposed to introduce Mg particles into the PLA matrix, which ensures good dispersion of the particles and better thermal properties, allowing for thermal processing routes such as extrusion or 3D printing via fused-filament fabrication. The thermal and physical properties are here studied in 1D single-filament-printed PLA/Mg composites with 0 to 10 wt.% of Mg particles by Differential Scanning Calorimetry (DSC); we analyse the PLA chain modifications produced, the crystallinity fraction, and the different crystalline forms of the PLA after thermal processing. Fourier Transform Infrared Spectroscopy (FTIR) is used to confirm the influence of the PLA/Mg colloidal processing after printing. The mechanical properties are measured with a universal tensile test machine on the 1D single-printed filaments via fused-filament fabrication (FFF); the filaments were naturally aged to stable conditions. Filaments with and without a notch are studied to obtain the materials' tensile strength, elastic modulus, and fracture toughness. Different analytical models to explain the results of the PLA-Mg were studied, in which the minimum values for the interface strength of the PLA-Mg composites were calculated.
CRIS-Team WoS Importer:2023-01-27

The pO-index and R ratio gap methods for the assessment of corrosion risk in refractory materials in contact with glass melts - Boccaccini, Dino N.; Cannio, Maria; Romagnoli, Marcello; Veronesi, Paolo; Leonelli, Cristina; Boccaccini, Aldo R. (Journal of the American Ceramic Society, 2010)
Corrosion of refractories used in glass melting technology is a complex phenomenon involving chemical wear (corrosion) and physical/mechanical wear (such as erosion and abrasion) processes as well as thermal shock and spalling. Besides the complexity in the hydrodynamics of a molten silicate bath with which refractory materials are in contact, refractories are polycrystalline heterogeneous materials containing a relatively high porosity. Pores are centers for accelerated corrosion, spalling, and penetration by the hot liquid. In this work, a corrosion study of aluminosilicate refractory crucibles by chromium and calcium oxides during the melting of Cr-containing soda lime glasses as a function of temperature (1400°-1500°C) and glass basicity has been performed. The features and mechanism of the corrosion process were compared and analyzed as a function of glass acidobasicity (pO-index) and of the ratio of network-dwelling cations to A13+ cations (R). The advantage of the pO-index and ΔR gap methods to assess refractory corrosion risk as a function of the acidobasicity differential between the refractory glassy phase and the glass melt was demonstrated. The change of the concentrations of glass constituents was monitored by ICP analysis of glass samples and correlated to the observed extent of corrosion. The crystalline composition and microstructure of the refractory materials before and after being corroded were studied by XRD analyses and SEM. Cr-doped corundum was found to be the main crystalline phase in the refractory microstructure and other mixed phases with chromium and aluminum and/or silica, which formed at the boundary layer (interface) between the glasses and the aluminosilicate refractory, were identified. The results provide a useful guide to the selection of refractory materials for application in glass and glass-ceramic manufacture in terms of their corrosion risk. © 2010 The American Ceramic Society.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.thepoi

The pro-angiogenic properties of multi-functional bioactive glass composite scaffolds - Gerhardt, Lutz-Christian; Widdows, Kate L.; Erol, Melek M.; Burch, Charles W.; Sanz-Herrera, Jose A.; Ochoa, Ignacio; Stämpfli, Rolf; Roqan, Iman S.; Gabe, Simon; Ansari, Tahera; Boccaccini, Aldo R. (Biomaterials, 2011)
The angiogenic properties of micron-sized (m-BG) and nano-sized (n-BG) bioactive glass (BG) filled poly(D,L lactide) (PDLLA) composites were investigated. On the basis of cell culture work investigating the secretion of vascular endothelial growth factor (VEGF) by human fibroblasts in contact with composite films (0, 5, 10, 20 wt %), porous 3D composite scaffolds, optimised with respect to the BG filler content capable of inducing angiogenic response, were produced. The in vivo vascularisation of the scaffolds was studied in a rat animal model and quantified using stereological analyses. The prepared scaffolds had high porosities (81-93%), permeability (k = 5.4-8.6 × 10-9 m2) and compressive strength values (0.4-1.6 MPa) all in the range of trabecular bone. On composite films containing 20 wt % m-BG or n-BG, human fibroblasts produced 5 times higher VEGF than on pure PDLLA films. After 8 weeks of implantation, m-BG and n-BG containing scaffolds were well-infiltrated with newly formed tissue and demonstrated higher vascularisation and percentage blood vessel to tissue (11.6-15.1%) than PDLLA scaffolds (8.5%). This work thus shows potential for the regeneration of hard-soft tissue defects and increased bone formation arising from enhanced vascularisation of the construct. © 2011 Elsevier Ltd.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.thepro
Keywords: Angiogenesis; Bioactive glass; Bone; Composite scaffold; Vascular endothelial growth factor; Vascularisation

Therapeutic inorganic ions in bioactive glasses to enhance bone formation and beyond - Hoppe, Alexander; Mourino, Viviana; Boccaccini, Aldo R. (Biomaterials Science, 2012)
UnivIS-Import:2015-03-09:Pub.2012.tech.IW.LM.therap

The relevance of biomaterials to the prevention and treatment of osteoporosis - Arcos, Daniel; Boccaccini, Aldo R.; Bohner, Marc; Diez-Perez, A.; Epple, M.; Gomez-Barrena, Enrique; Herrera, Antonio; Planell, J. A.; Rodriguez-Manas, L.; Vallet-Regi, Maria (Acta Biomaterialia, 2014)
Osteoporosis is a worldwide disease with a very high prevalence in humans older than 50. The main clinical consequences are bone fractures, which often lead to patient disability or even death. A number of commercial biomaterials are currently used to treat osteoporotic bone fractures, but most of these have not been specifically designed for that purpose. Many drug- or cell-loaded biomaterials have been proposed in research laboratories, but very few have received approval for commercial use. In order to analyze this scenario and propose alternatives to overcome it, the Spanish and European Network of Excellence for the Prevention and Treatment of Osteoporotic Fractures, "Ageing", was created. This network integrates three communities, e.g. clinicians, materials scientists and industrial advisors, tackling the same problem from three different points of view. Keeping in mind the premise "living longer, living better", this commentary is the result of the thoughts, proposals and conclusions obtained after one year working in the framework of this network. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Keywords: Ageing; Biomaterials; Bone; Osteoporosis

Thermal analysis and in vitro bioactivity of bioactive glass-alumina composites - Chatzistavrou, Xanthippi; Kantiranis, Nikolaos; Kontonasaki, Eleana; Chrissafis, Konstantinos; Papadopoulou, Labrini; Koidis, Petros; Boccaccini, Aldo R.; Paraskevopoulos, Konstantinos M. (Materials Characterization, 2011)
Bioactive glass-alumina composite (BA) pellets were fabricated in the range 95/5-60/40 wt.% respectively and were heat-treated under a specific thermal treatment up to 950 °C. Control (unheated) and heat-treated pellets were immersed in Simulated Body Fluid (SBF) for bioactivity testing. All pellets before and after immersion in SBF were studied by Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM-EDS) and X-ray Diffraction (XRD) analysis. All composite pellets presented bioactive response. On the surface of the heat-treated pellets the development of a rich biological hydroxyapatite (HAp) layer was delayed for one day, compared to the respective control pellets. Independent of the proportion of the two components, all composites of each group (control and heat-treated) presented the same bioactive response as a function of immersion time in SBF. It was found that by the applied methodology, Al2O3 can be successfully applied in bioactive glass composites without obstructing their bioactive response. © 2010 Elsevier Inc. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.therma
Keywords: Al; Apatite; Bioactive glass; Composites; Thermal properties

Thermal and mechanical properties of a foamed glass-ceramic material produced from silicate wastes - Boccaccini, Aldo R.; et al. (Glass Technology, 2007)
Lightweight glass-ceramic foams produced from silicate wastes have been characterised with regards to their thermal and mechanical properties. The level of porosity of the fabricated foams was controlled by varying the heat treatment temperature and the amount of foaming agent. Lee's Disc was used to measure the thermal conductivity of each type of foam in order to assess its potential as a thermal insulator. The most porous material, with a porosity of 90%, achieved a thermal conductivity of about 0.2 Wm-1 K -1. Good agreement was obtained between experimental conductivity data and simulated values obtained by a finite element analysis, which employed structural information obtained from x-ray microtomography. Mechanical properties, such as Young's modulus, flexural and crushing strength of foams of various densities, were also determined in this study. Correlations against well known models indicated the waste derived foams behaved in a manner typical of brittle foams. The study provides an understanding of the thermal and mechanical behaviour of glass-ceramic foams; these waste derived materials show potential for thermal insulation applications.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.therma

Thermal and tribo-mechanical properties of high-performance poly(etheretherketone)/reduced graphene oxide nanocomposite coatings prepared by electrophoretic deposition - González Castillo, Eduin Ivan; Torres, Yadir; González, Francisco J.; Aguilar Rabiela, Arturo Elias; Shuttleworth, Peter S.; Ellis, Gary J.; Boccaccini, Aldo R. (Journal of Materials Science, 2023)
The thermal stability and degradation, near-to-surface mechanical properties, and scratch resistance and damage mechanism of poly(etheretherketone) (PEEK)/reduced graphene oxide (RGO) nanocomposite coatings are analyzed and discussed in terms of their nanosheet content and microstructure. Although RGO modified the thermal stability and degradation of the polymeric matrix, for instance, by slightly reducing the onset degradation temperature, its addition was not a limiting factor in the PEEK processing. Respecting the microstructural features induced by the nanosheets, the nanocomposite coatings were found to exhibit (i) a partially exfoliated and large-scale co-continuous morphology related to RGO nanosheets whose basal planes were mainly aligned with the coating surface, (ii) a dendritic morphology of PEEK domains related to transcrystallinity, (iii) and irregular domains associated with the deposition of PEEK particles wrapped by the nanosheets. The changes provoked by RGO in the morphology and PEEK crystalline phase influenced the near-to-surface mechanical properties, scratch resistance, and scratch damage mechanism of the nanocomposite coatings. Within this context, the interlayer strength between the nanosheets in the large-scale co-continuous morphology and PEEK transcrystallinity had an important effect. Furthermore, the random-bumpy surface texture formed by the irregular PEEK domains together with the conformal cracking damage mechanism was decisive in the scratch response of the PEEK/RGO nanocomposite coatings. The comprehensive characterization carried out in this work concludes that PEEK/RGO electrophoretic coatings are suitable for a variety of applications requiring tribo-mechanical resistance. Graphical Abstract: [Figure not available: see fulltext.].
CRIS-Team Scopus Importer:2023-06-30

Thermal degradation kinetics and decomposition mechanism of PBSu nanocomposites with silica-nanotubes and strontium hydroxyapatite nanorods - Papageorgiou, D. G.; Roumeli, E.; Chrissafis, K.; Lioutas, Ch.; Triantafyllidis, K.; Bikiaris, D.; Boccaccini, Aldo R. (Physical Chemistry Chemical Physics, 2014)
Novel poly(butylene succinate) (PBSu) nanocomposites containing 5 and 20 wt% mesoporous strontium hydroxyapatite nanorods (SrHNRs) and silica nanotubes (SiNTs) were prepared by melt-mixing. A systematic investigation of the thermal stability and decomposition kinetics of PBSu was performed using pyrolysis-gas chromatography-mass spectroscopy (Py-GC-MS) and thermogravimetry (TG). Thorough studies of evolving decomposition compounds along with the isoconversional and model-fitting analysis of mass loss data led to the proposal of a decomposition mechanism for PBSu. Moreover, the effects of SrHNRs and SiNTs on the thermal stability and decomposition kinetics of PBSu were also examined in detail. The complementary use of these techniques revealed that the incorporation of SiNTs in PBSu does not induce significant effects neither on its thermal stability nor on its decomposition mechanism. In contrast, the addition of SrHNRs resulted in the catalysis of the initial decomposition steps of PBSu and also in modified decomposition mechanisms and activation energies. The evolving gaseous products of PBSu and their evolution pattern in the SiNT nanocomposites were the same as in neat PBSu, while they were slightly modified for the SrHNR nanocomposites, confirming the findings from thermogravimetric analysis. © 2014 the Owner Societies.

Thermally triggered injectable chitosan/silk fibroin/bioactive glass nanoparticle hydrogels for in-situ bone formation in rat calvarial bone defects - Wu, Jingjing; Zheng, Kai; Huang, Xuetao; Liu, Jiaoyan; Liu, Haoming; Boccaccini, Aldo R.; Wan, Ying; Guo, Xiaodong; Shao, Zengwu (Acta Biomaterialia, 2019)
Copper-containing bioactive glass nanoparticles (Cu-BG NPs) with designed compositions and sizes were synthesized and incorporated into chitosan (CH)/silk fibroin (SF)/glycerophosphate (GP) composites to prepare injectable hydrogels for cell-free bone repair. The resulting Cu-BG/CH/SF/GP gels were found to exhibit well-defined injectability and to undergo rapid gelation at physiological temperature and pH. They were highly porous and showed the ability to administer Si, Ca and Cu ions at their respective safe doses in a sustained and controlled manner. In vitro studies revealed that the gels supported the growth of seeded MC3T3-E1 and human umbilical vein endothelial cells, and effectively induced them toward osteogenesis and angiogenesis, respectively. In vivo bone repair based on a critical-size rat calvarial bone defect model demonstrated that the optimal Cu-BG/CH/SF/GP gel was able to fully restore the bone defect with formation of vascularized bone tissue and mineralized collagen deposition during a treatment period of 8 weeks without utilization of any cells and/or growth factors. The results suggest that the presently developed Cu-BG/CH/SF/GP composite hydrogels have great potential and translation ability for bone regeneration owing to their thermo-sensitive properties, cell-free bioactivity, and cost-effectiveness. Statement of Significance: Hydrogels loaded with cells and/or growth factors exhibit potential in bone repair. However, they have been facing obstacles related to the clinic translation. Here, a novel type of hydrogel system consisting of copper-containing bioactive glass nanoparticles and chitosan/silk fibroin composite was developed. These gels showed injectability and thermally triggered in situ gelation properties and were able to administer the release of ions at safe but effective doses in a controlled manner while inducing the seeded cells toward osteogenesis and angiogenesis. The optimal gel showed the ability to fully repair critical-size rat calvarial bone defects without involving time consuming cell processing and/or the use of expensive growth factors, confirming that this novel hydrogel system has great potential for translation to the clinic.
CRIS-Team Scopus Importer:2019-05-09
Keywords: Bioactive glass nanoparticles; Bone regeneration; Chitosan; Osteogenesis and angiogenesis; Thermosensitive hydrogel

Thermal plasma technology for the treatment of wastes: a critical review - Gomez, E.; Rani, D. Amutha; Cheeseman, C. R.; Deegan, D.; Wise, M.; Boccaccini, Aldo R. (Journal of Hazardous Materials, 2009)
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.therma

Thermal shock behaviour of mullite-cordierite refractory materials - Boccaccini, Aldo R.; et al. (Advances in Applied Ceramics, 2007)
The characterisation of thermal shock damage in cordierite-mullite refractory plates used as substrates in fast firing of porcelain whiteware has been investigated. Two different refractory compositions (termed REFO and CONC), characterised by different silica to alumina ratios, were studied. Thermal shock damage was induced in as received samples by water quenching tests from 1250°C. Thermal and mechanical properties were measured at room temperature by means of standard techniques and then the thermal shock resistance parameter R was calculated. The fracture toughness of selected samples was measured before and after thermal shock by the chevron notched specimen technique. The reliability of this technique for evaluation of small differences in fracture toughness after a given number of thermal shock cycles was investigated. The suitability of Klc measurements by the chevron notched specimen technique to characterise the development of thermal shock damage in refractory materials was proved in this investigation. © 2007 Institute of Materials, Minerals and Mining.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.therma_5
Keywords: Fracture toughness; Refractory materials; Thermal shock

The role of (HCO3)- ions in SBF on the interaction with bioactive glass-ceramic scaffold - Kulhankova, J.; Rohanova, D.; Horkavcova, D.; Bezdicka, P.; Boccaccini, Aldo R. (Materials Today Chemistry, 2023)
Simulated Body Fluid (SBF) has concentrations of inorganic elements nearly equal to those of human blood plasma (BP). However, there are some differences between SBF and BP which can distort the results of in vitro bioactivity tests. Contrary to BP, SBF has a too low concentration of (HCO3)- ions (only 4 instead of 27 mmol center dot dm-3) and on the contrary a higher concentration of Cl- ions (introduced by the TRIS-HCl buffer). Indeed, the main difference between SBF and BP is the presence of the TRIS buffer in SBF which is used for neutral pH maintaining. The aim of this work was to study the effect of (HCO3)- ions in non-buffered SBF on the solubility of a bioactive glass-ceramic material and the formation of a new phase on the sample surface. A highly reactive glass-ceramic scaffold derived from 45S5 bioactive glass was tested under static-dynamic conditions using SBF solution with different (HCO3)- ion concentrations (4, 20 and 27 mmol center dot dm-3). The results were compared with data obtained using standardized buffered SBF solution. A non-buffered SBF solution with a concentration of (HCO3)- ions closer to the real concentration in BP was shown to have the potential to replace the standardized SBF solution since the ISO 23317:2014 using SBF can give false-positive results of in vitro bioactivity tests. (c) 2022 Elsevier Ltd. All rights reserved.
CRIS-Team WoS Importer:2023-03-03

The role of osteoclasts in bone tissue engineering - Detsch, Rainer; Boccaccini, Aldo R. (Journal of Tissue Engineering and Regenerative Medicine, 2014)
The success of scaffold-based bone regeneration approaches strongly depends on the performance of the biomaterial utilized. Within the efforts of regenerative medicine towards a restitutio ad integrum (i.e. complete reconstruction of a diseased tissue), scaffolds should be completely degraded within an adequate period of time. The degradation of synthetic bone substitute materials involves both chemical dissolution (physicochemical degradation) and resorption (cellular degradation by osteoclasts). Responsible for bone resorption are osteoclasts, cells of haematopoietic origin. Osteoclasts play also a crucial role in bone remodelling, which is essential for the regeneration of bone defects. There is, however, surprisingly limited knowledge about the detailed effects of osteoclasts on biomaterials degradation behaviour. This review covers the relevant fundamental knowledge and progress made in the field of osteoclast activity related to biomaterials used for bone regeneration. In vitro studies with osteoclastic precursor cells on synthetic bone substitute materials show that there are specific parameters that inhibit or enhance resorption. Moreover, analyses of the bone-material interface reveal that biomaterials composition has a significant influence on their degradation in contact with osteoclasts. Crystallinity, grain size, surface bioactivity and density of the surface seem to have a less significant effect on osteoclastic activity. In addition, the topography of the scaffold surface can be tailored to affect the development and spreading of osteoclast cells. The present review also highlights possible areas on which future research is needed and which are relevant to enhance our understanding of the complex role of osteoclasts in bone tissue engineering. © 2014 John Wiley & Sons, Ltd.
Keywords: Bioactive glasses; Bone resorption; Bone tissue engineering; Calcium phosphates; Osteoclasts; Scaffolds

The use of murine embryonic stem cells, alginate encapsulation, and rotary microgravity bioreactor in bone tissue engineering - Hwang, Yu-Shik; Cho, Johann; Tay, Feng; Heng, Jerry Y. Y.; Ho, Raimundo; Kazarian, Sefgei G.; Williams, Daryl R.; Boccaccini, Aldo R.; Polak, Julia M.; Mantalaris, Athanasios (Biomaterials, 2009)
The application of embryonic stem cells (ESCs) in bone tissue engineering and regenerative medicine requires the development of suitable bioprocesses that facilitate the integrated, reproducible, automatable production of clinically-relevant, scaleable, and integrated bioprocesses that generate sufficient cell numbers resulting in the formation of three-dimensional (3D) mineralised, bone tissue-like constructs. Previously, we have reported the enhanced differentiation of undifferentiated mESCs toward the osteogenic lineage in the absence of embryoid body formation. Herein, we present an efficient and integrated 3D bioprocess based on the encapsulation of undifferentiated mESCs within alginate hydrogels and culture in a rotary cell culture microgravity bioreactor. Specifically, for the first 3 days, encapsulated mESCs were cultured in 50% (v/v) HepG2 conditioned medium to generate a cell population with enhanced mesodermal differentiation capability followed by osteogenic differentiation using osteogenic media containing ascorbic acid, β-glycerophosphate and dexamethasone. 3D mineralised constructs were generated that displayed the morphological, phenotypical, and molecular attributes of the osteogenic lineage, as well mechanical strength and mineralised calcium/phosphate deposition. Consequently, this bioprocess provides an efficient, automatable, scalable and functional culture system for application to bone tissue engineering in the context of macroscopic bone formation. © 2008.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.theuse
Keywords: Alginate hydrogels; Embryonic stem cells; Mineralisation; Osteogenic differentiation; Three-dimensional bioprocessing

THREE-DEMENSIONAL (3D) BIONTLAIETIC CULTURE ON POLY(EPSILON CAPROLACIONE) (PCL) PATTERNED SCAFFOLDS: A TISSIT ENGINEERING APPROACH TARGETING EARLY STAGE OF FOLLI-CULOGENESIS UP TO OOCYTE MATURATION - Di Berardino, Chiara; Peserico, Alessia; Liverani, Liliana; Capacchietti, Giulia; Russo, Valentina; Bernabo, Nicola; Boccaccini, Aldo R.; Barboni, Barbara (FERTILITY AND STERILITY, 2022)
CRIS-Team WoS Importer:2023-03-17

Three-Dimensional Mineralization of Dense Nanofibrillar Collagen-Bioglass Hybrid Scaffolds - Marelli, Benedetto; Ghezzi, Chiara E.; Barralet, Jake E.; Boccaccini, Aldo R.; Nazhat, Showan N. (Biomacromolecules, 2010)
Scaffolds for bone tissue engineering must meet a number of requirements such as biocompatibility, osteoconductivity, osteoinductivity, biodegradability, and appropriate biomechanical properties. A combination of type I collagen and 45S5 Bioglass may meet these requirements, however, little has been demonstrated on the effect of Bioglass on the potential of the collagen nanofibrillar three-dimensional mineralization and its influence on the structural and mechanical properties of the scaffolds. In this work, rapidly fabricated dense collagen-Bioglass hybrid scaffolds were assessed for their potential for immediate implantation. Hybrid scaffolds were conditioned, in vitro, in simulated body fluid (SBF) for up to 14 days and assessed in terms of changes in structural, chemical, and mechanical properties. MicroCT and SEM analyses showed a homogeneous distribution of Bioglass particles in the as-made hybrids. Mineralization was detected at day 1 in SBF, while ATR-FTIR microscopy and XRD revealed the presence of hydroxyl-carbonated apatite on the surface and within the two hybrid scaffolds at days 7 and 14. FTIR and SEM confirmed that the triple helical structure and typical banding pattern of fibrillar collagen was maintained as a function of time in SBF. Principal component analysis executed on ATR-FTIR microscopy revealed that the mineralization extent was a function of both Bioglass content and conditioning time in SBF. Tensile mechanical analysis showed an increase in the elastic modulus and a corresponding decrease in strain at ultimate tensile strength (UTS) as imparted by mineralization of scaffolds as a function of time in SBF and Bioglass content. Change in UTS was affected by Bioglass content. These results suggested the achievement of a hybrid matrix potentially suitable for bone tissue engineering. © 2010 American Chemical Society.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.threed

Three-dimensional polymer coated 45S5-type bioactive glass scaffolds seeded with human mesenchymal stem cells show bone formation in vivo - Westhauser, Fabian; Weis, Christian; Prokscha, Matthaeus; Bittrich, Leonie A.; Li, Wei; Xiao, Kai; Kneser, Ulrich; Kauczor, Hans-Ulrich; Schmidmaier, Gerhard; Boccaccini, Aldo R.; Moghaddam, Arash (Journal of Materials Science: Materials in Medicine, 2016)

Three-dimensional reconstruction of a nickel- alumina composite coating by FIB-SIMS - Chater, Richard J.; Corni, Ilaria; Boccaccini, Aldo R.; Ryan, Mary P. (Surface and Interface Analysis, 2011)
The alumina particle distribution in a nickel-alumina composite coating on stainless steel was determined using the aluminum secondary ion images that were generated by sputtering a cross-section of the coating with a highly focused gallium primary ion beam (FIB). Thin slices of the coating were removed using the same beam with further imaging of the fresh surface which was very smooth despite the difference in the sputter rates of the two materials. Sequential SIMS imaging and sectioning resulted in a sequence of images from which the 3D distribution of the alumina particles in the composite coating was reconstructed. Copyright © 2010 John Wiley & Sons, Ltd.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.threed
Keywords: 3D reconstruction; alumina particle; FIB-SIMS; nickel coating; SIMS imaging

Time-dependent hyper-viscoelastic parameter identification of human articular cartilage and substitute materials - Weizel, A.; Distler, Thomas; Detsch, Rainer; Boccaccini, Aldo R.; Seitz, H.; Budday, Silvia (Journal of the Mechanical Behavior of Biomedical Materials, 2023)
Numerical simulations are a valuable tool to understand which processes during mechanical stimulations of hydrogels for cartilage replacement influence the behavior of chondrocytes and contribute to the success or failure of these materials as implants. Such simulations critically rely on the correct prediction of the material response through appropriate material models and corresponding parameters. In this study, we identify hyper-viscoelastic material parameters for numerical simulations in COMSOL Multiphysics® v. 5.6 for human articular cartilage and two replacement materials, the commercially available ChondroFillerliquid and oxidized alginate gelatin (ADA-GEL) hydrogels. We incorporate the realistic experimental boundary conditions into an inverse parameter identification scheme based on data from multiple loading modes simultaneously, including cyclic compression-tension and stress relaxation experiments. We provide individual parameter sets for the unconditioned and conditioned responses and discuss how viscoelastic effects are related to the materials’ microstructure. ADA-GEL and ChondroFillerliquid exhibit faster stress relaxation than cartilage with lower relaxation time constants, while cartilage has the largest viscoelastic stress contribution. The elastic response predominates in ADA-GEL and ChondroFillerliquid, while the viscoelastic response predominates in cartilage. These results will help to simulate mechanical stimulations, support the development of suitable materials with distinct mechanical properties in the future and provide parameters and insight into the time-dependent material behavior of human articular cartilage.
CRIS-Team Scopus Importer:2023-01-06
Keywords: Finite viscoelasticity; Human articular cartilage; Hydrogels; Parameter identification; Tissue engineering

Timing of calcium nitrate addition affects morphology, dispersity and composition of bioactive glass nanoparticles - Zheng, Kai; Taccardi, Nicola; Maria Beltran, Ana; Sui, Baiyan; Zhou, Tian; Marthala, Venkata; Hartmann, Martin; Boccaccini, Aldo R. (RSC Advances, 2016)
Bioactive glass nanoparticles (BGN) are promising materials for a number of biomedical applications. Many parameters related to the synthesis of BGN using sol-gel methods can affect their characteristics. In this study, the influence of timing of calcium nitrate (calcium precursor) addition during processing on BGN characteristics was investigated. The results showed that the addition timing could affect the morphology, dispersity and composition of BGN. With delayed addition of calcium nitrate, larger, more regular and better dispersed BGN could be synthesized while the gap between nominal and actual compositions of BGN was widened. However, the addition timing had no significant influence on structural characteristics, as BGN with different addition-timing of calcium nitrate exhibited similar infrared spectra and amorphous nature. The results also suggested that monodispersed BGN could be synthesized by carefully controlling the addition of calcium nitrate. The synthesized monodispersed BGN could release Si and Ca ions continuously for up to at least 14 days. They also showed in vitro bioactivity and non-cytotoxicity towards rat bone marrow-derived mesenchymal stem cells (rBMSCs). In conclusion, the timing of calcium precursor addition is an essential parameter to be considered when producing BGN which should exhibit monodisperse characteristics for biomedical applications.

Tinten für die Biofabrikation–Druckbarkeit vs. Biokompatibilität? - Kuth, Sonja; Lorke, Markus; Frischknecht, Renato; Boccaccini, Aldo R. (BioSpektrum, 2023)
In biomaterial ink development, achieving optimal performance is a complex process. A biomaterial ink that shows excellent printability may be inferior in terms of cell compatibility. Properties facilitating printability of biomaterial inks include, among others, viscosity and stiffness. Research shows that stiffness plays a pivotal role in dictating cell response. Neurons used in this study require an exceptionally low matrix stiffness, which may not show best printability results when realized in a biomaterial ink.
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TiO2-PLLA nanocomposite coatings and free-standing films by a combined electrophoretic deposition-dip coating process - Chavez-Valdez, Alejandra; Arizmendi-Morquecho, Ana; Moreno Bello, Karla; Roether, Judith; Kaschta, Joachim; Boccaccini, Aldo R. (Composites Part B-Engineering, 2014)
TiO2/PLLA nanocomposites were prepared using a two-step process involving electrophoretic deposition (EPD) and dip coating (DC). EPD was carried out first to obtain porous TiO2 nanostructured coatings while subsequent dip coating was performed using different concentrations of PLLA in dichloromethane (DCM) to obtain nanocomposite materials. According to SEM images, cracks in the TiO2 nanostructured coatings, developed upon drying, were filled with the polymer which led to improvement of the flexibility of the nanocomposite coatings. Similarly, a surface modification from hydrophilic to hydrophobic was obtained with the addition of the polymer. FTIR analysis showed characteristic bands of both materials, TiO2 and PLLA, both on the coating surface and at the interphase between the nanocomposite coating and the substrate. Hardness measurements showed a maximum value of 1.4 GPa for TiO2-10 wt% PLLA composite. For DMTA tests, detached layers were used and the storage and loss moduli were determined. TiO2-PLLA nanocomposite coatings showed higher values of storage modulus at higher temperature in comparison to pure PLLA samples. Also, there was a shift in the glass transition temperature (T-g) with increasing TiO2 content. In conclusion, the EPD-DC combined technique proposed here enables the fabrication of nanostructured coatings and free-standing layers in which the quantity of PLLA can be changed according to the intended application, i.e. it is possible to fabricate coatings with tailored degradability and suitable mechanical properties with low additions of PLLA or free standing films with increased flexibility, biodegradability and biocompatibility with high amounts of PLLA. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Nanostructures; Particle-reinforcement; Mechanical properties; Surface properties; Electrophoretic deposition

TiO2-PLLA nanocomposite coatings and free-standing films by a combined electrophoretic deposition-dip coating process - Chavez-Valdez, Alejandra; Arizmendi-Morquecho, Ana; Moreno, K. J.; Roether, Judith; Kaschta, Joachim; Boccaccini, Aldo R. (Composites Part B-Engineering, 2014)
TiO2/PLLA nanocomposites were prepared using a two-step process involving electrophoretic deposition (EPD) and dip coating (DC). EPD was carried out first to obtain porous TiO2 nanostructured coatings while subsequent dip coating was performed using different concentrations of PLLA in dichloromethane (DCM) to obtain nanocomposite materials. According to SEM images, cracks in the TiO2 nanostructured coatings, developed upon drying, were filled with the polymer which led to improvement of the flexibility of the nanocomposite coatings. Similarly, a surface modification from hydrophilic to hydrophobic was obtained with the addition of the polymer. FTIR analysis showed characteristic bands of both materials, TiO2 and PLLA, both on the coating surface and at the interphase between the nanocomposite coating and the substrate. Hardness measurements showed a maximum value of 1.4 GPa for TiO2–10 wt% PLLA composite. For DMTA tests, detached layers were used and the storage and loss moduli were determined. TiO2–PLLA nanocomposite coatings showed higher values of storage modulus at higher temperature in comparison to pure PLLA samples. Also, there was a shift in the glass transition temperature (Tg) with increasing TiO2 content. In conclusion, the EPD–DC combined technique proposed here enables the fabrication of nanostructured coatings and free-standing layers in which the quantity of PLLA can be changed according to the intended application, i.e. it is possible to fabricate coatings with tailored degradability and suitable mechanical properties with low additions of PLLA or free standing films with increased flexibility, biodegradability and biocompatibility with high amounts of PLLA.
Keywords: B. Mechanical properties; B. Surface properties; A. Nanostructures; A. Particle-reinforcement; Electrophoretic deposition

Tissue engineering of electrically responsive tissues using polyaniline based polymers: A review - Qazi, Taimoor Hasan; Rai, Ranjana; Boccaccini, Aldo R. (Biomaterials, 2014)
Conducting polymers have found numerous applications as biomaterial components serving to effectively deliver electrical signals from an external source to the seeded cells. Several cell types including cardiomyocytes, neurons, and osteoblasts respond to electrical signals by improving their functional outcomes. Although a wide variety of conducting polymers are available, polyaniline (PANI) has emerged as a popular choice due to its attractive properties such as ease of synthesis, tunable conductivity, environmental stability, and biocompatibility. PANI in its pure form has exhibited biocompatibility both invitro and invivo, and has been combined with a host of biodegradable polymers to form composites having a range of mechanical, electrical, and surface properties. Moreover, recent studies in literature report on the functionalization of polyaniline oligomers with end segments that make it biodegradable and improve its biocompatibility, two properties which make these materials highly desirable for applications in tissue engineering. This review will discuss the features and properties of PANI based composites that make them effective biomaterials, and it provides a comprehensive summary of studies where the use of PANI as a biomaterial component has enhanced cellular function and behavior. We also discuss recent studies utilizing functionalized PANI oligomers, and conclude that electroactive PANI and its derivatives show great promise in eliciting favorable responses from various cell lines that respond to electrical stimuli, and are therefore effective biomaterials for the engineering of electrically responsive biological tissues and organs. © 2014 Elsevier Ltd.
Keywords: Conducting polymers; Electrical stimulation; Polyaniline; Polyaniline oligomers; Tissue engineering

Tissue Engineering Using Ceramics and Polymers: Second Edition - Boccaccini, Aldo R.; Ma, Peter X. (Elsevier Inc., 2014)
The second edition of Tissue Engineering Using Ceramics and Polymers comprehensively reviews the latest advances in this area rapidly evolving area of biomaterials science. Part one considers the biomaterials used for tissue engineering. It introduces the properties and processing of bioactive ceramics and glasses, as well as polymeric biomaterials, particularly biodegradable polymer phase nanocomposites. Part two reviews the advances in techniques for processing, characterization, and modeling of materials. The topics covered range from nanoscale design in biomineralization strategies for bone tissue engineering to microscopy techniques for characterizing cells to materials for perfusion bioreactors. Further, carrier systems and biosensors in biomedical applications are considered. Finally, part three looks at the specific types of tissue and organ regeneration, with chapters concerning kidney, bladder, peripheral nerve, small intestine, skeletal muscle, cartilage, liver, and myocardial tissue engineering. Important developments in collagen-based tubular constructs, bioceramic nanoparticles, and multifunctional scaffolds for tissue engineering and drug delivery are also explained. Tissue Engineering Using Ceramics and Polymers is a valuable reference tool for both academic researchers and scientists involved in biomaterials or tissue engineering, including the areas of bone and soft-tissue reconstruction and repair, and organ regeneration. Second edition comprehensively examines the latest advances in ceramic and polymers in tissue engineering. Provides readers with general information on polymers and ceramics and looks at the processing, characterization, and modeling. Reviews the latest research and advances in tissue and organ regeneration using ceramics and polymers.
CRIS-Team Scopus Importer:2022-08-05

Tissue imaging with 2-photon microscopy - Vielreicher, Martin; Schürmann, Sebastian; Detsch, Rainer; Boccaccini, Aldo R.; Arkudas, Andreas; Friedrich, Oliver (BioNanoMaterials, 2013)

Titania and titania-silver nanocomposite coatings grown by electrophoretic deposition from aqueous suspensions - Santillan, M. J.; Quaranta, N. E.; Boccaccini, Aldo R. (Surface & Coatings Technology, 2010)
This study focused on the synthesis of titania-silver (TiO2-Ag) nanocomposite coatings with potential enhanced antibacterial properties for applications in orthopedic implants. Ag nanoparticles (4nm) were grown directly on the surface of commercially available TiO2 nanoparticles (23nm) by nucleophilic reaction. The electrophoretic deposition (EPD) of TiO2 and TiO2-Ag nanoparticles on titanium substrates using aqueous suspensions was investigated. Best results were achieved by using water and ethanol as co-solvents. The EPD process (voltage: 3V, deposition time: 90s) led to TiO2 based coatings on titanium substrates exhibiting homogeneous and uniform microstructure. In vitro bioactivity tests in Kokubo's simulated body fluid (SBF) to evaluate the formation of hydroxyapatite (HA) on the coating surface were performed. The results showed that the extent of HA formation rapidly increased with increasing time in SBF and it decreased as silver amount in the coating increased. XRD, TEM and SEM-EDAX were used to investigate the microstructure of the nanomaterials and coatings. The high bioactivity of the TiO2 based electrophoretic coatings indicates their potential for use as bioactive antibacterial layers in orthopedic implants. © 2010 Elsevier B.V.
UnivIS-Import:2015-03-09:Pub.2010.tech.IW.LM.titani
Keywords: Antibacterial coatings; Biomedical applications; Electrophoretic deposition; Silver nanoparticles; Titania coatings

Titanium dioxide (TiO2) nanoparticles filled poly(D,L lactid acid) (PDLLA) matrix composites for bone tissue engineering - Boccaccini, Aldo R.; et al. (Journal of Materials Science: Materials in Medicine, 2007)
Titanium dioxide (TiO2) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(d,l lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO2 nanoparticles were processed by solvent casting. Bioactivity, characterised by formation of hydroxyapatite (HA) on the materials surface, was investigated for both the free TiO2 nanoparticles and PDLLA/TiO2 composite films upon immersion in supersaturated simulated body fluid (1.5 SBF) for up to 3 weeks. Non-stoichiometric HA nanocrystals (ns-HA) with an average diameter of 40 nm were formed on the high content (30 wt% TiO2) composite films after 2 weeks of immersion in 1.5 SBF. For the pure PDLLA film and the low content composite films (5 wt% TiO2) trace amounts of ns-HA nanocrystals were apparent after 3 weeks. The TiO2 nanopowder alone showed no bioactivity. The effect of TiO2 nanoparticles (0.5-10,000 μg/mL) on MG-63 osteoblast-like cell metabolic activity was assessed by the MTT assay. TiO2 particle concentrations of up to 100 μg/mL had no significant effect on MG-63 cell viability. © 2007 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.titani

Top-down processing of submicron 45S5 Bioglass® for enhanced in vitro bioactivity and biocompatibility - Romeis, Stefan; Hoppe, Alexander; Detsch, Rainer; Boccaccini, Aldo R.; Schmidt, Jochen; Peukert, Wolfgang (Procedia Engineering, 2015)
45S5 Bioglass® (45S5BG - 45 wt.% SiO, 24.5 wt.% CaO, 24.5 wt.% NaO and 6 wt.% PO glass forming system) is a frequently applied type A bioactive material, forming an inherent bond to bone and soft tissue. Recent studies for nanometer sized bioactive glasses (nBG) have indicated their great potential for several biomedical applications. It is recognized that cost-efficient processing routes are required for the development of submicron bioactive glasses, given the advantages associated with the nanoscale. In this study, the potential of top-down processing of 45S5BG by wet comminution in a stirred media mill is investigated and the key importance of the used solvents is revealed: whereas bioactive submicron particles can be produced in organic solvents, as shown exemplarily for n-pentanol, bioactivity is lost after processing in water. Analysis of the elemental constituents in the solid phase by ICP-OES indicates enhanced dissolution during processing in water, i.e. The glass composition is changing during processing. In n-pentanol the overall composition and structure is maintained and only the formation of surface carbonates is observed; flake-like particles are obtained. As a marker for bioactivity in vitro hydroxycarbonate apatite formation as determined by FTIR is used; biocompatibility is addressed by in vitro incubation with osteoblast like MG-63 cells. All-together, we propose wet comminution under controlled conditions as an appropriate technique to produce submicrometer bioactive glass particles with enhanced bioactivit
Keywords: in vitro bioactivity and biocompatibility; solvent influence; submicron 45S5 Bioglass®; top-down

Top-down processing of submicron 45S5 Bioglass (R) for enhanced in vitro bioactivity and biocompatibility - Romeis, Stefan; Hoppe, Alexander; Detsch, Rainer; Boccaccini, Aldo R.; Schmidt, Jochen; Peukert, Wolfgang (2015)
45S5 Bioglass (R) (45S5BG - 45 wt.% SiO2, 24.5 wt.% CaO, 24.5 wt.% Na2O and 6 wt.% P2O5 glass forming system) is a frequently applied type A bioactive material, forming an inherent bond to bone and soft tissue. Recent studies for nanometer sized bioactive glasses (nBG) have indicated their great potential for several biomedical applications. It is recognized that cost-efficient processing routes are required for the development of submicron bioactive glasses, given the advantages associated with the nanoscale. In this study, the potential of top-down processing of 45S5BG by wet comminution in a stirred media mill is investigated and the key importance of the used solvents is revealed: whereas bioactive submicron particles can be produced in organic solvents, as shown exemplarily for n-pentanol, bioactivity is lost after processing in water. Analysis of the elemental constituents in the solid phase by ICP-OES indicates enhanced dissolution during processing in water, i.e. the glass composition is changing during processing. In n-pentanol the overall composition and structure is maintained and only the formation of surface carbonates is observed; flake-like particles are obtained. As a marker for bioactivity in vitro hydroxycarbonate apatite formation as determined by FTIR is used; biocompatibility is addressed by in vitro incubation with osteoblast like MG-63 cells. All-together, we propose wet comminution under controlled conditions as an appropriate technique to produce submicrometer bioactive glass particles with enhanced bioactivity. (C) 2015 The Authors. Published by Elsevier Ltd.
Keywords: submicron 45S5 Bioglass (R); top-down; solvent influence; in vitro bioactivity and biocompatibility

Topical systems for the controlled release of antineoplastic Drugs: Oxidized Alginate-Gelatin Hydrogel/Unilamellar vesicles - Stagnoli, Soledad; Garro, Cintia; Ertekin, Özlem; Heid, Susanne; Seyferth, Stefan; Soria, Gastón; Mariano Correa, N.; Leal-Egaña, Aldo; Boccaccini, Aldo R. (Journal of Colloid and Interface Science, 2023)
The efficacy of chemotherapeutic procedures relies on delivering proper concentrations of anti-cancer drugs in the tumor surroundings, so as to prevent potential side effects on healthy tissues. Novel drug carrier platforms should not just be able to deliver anticancer molecules, but also allow for adjustements in the way these drugs are administered to the patients. We developed a system for delivering water-insoluble drugs, based on the use of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), or bis(2-ethylhexyl) sulfosuccinate benzyl-n-hexadecyldimethylammonium (BHD-AOT), embedded into oxidized alginate-gelatin (ADA/Gel) hydrogel, emulating a patch for topic applications. After being loaded with curcumin, cancer cells such as human colorectal adenocarcinoma (HCT116 and DLD-1) and melanoma cell lines (MEL501), and non-malignant cells such as mammary epithelial cell lines (NMuMG) and embryonal fibroblasts (NIH 3T3 or NEO cells) were analyzed for biocompatibility and cytotoxic effects. The results show that the proposed system can load comparatively higher concentrations of the drug (with respect to other nano/microcarriers in the literature), and that it can enhance the likelihood of the drug being uptaken by cancer cells instead of non-malignant cells. These assays were complemented by diffusion studies across the stratum corneum of rat skin, with the aim of determining the system's efficiency during topical application. Finally, the stability of the patch was tested after lyophilization to determine its potential pharmaceutical use. As a whole, the combined system represents a highly reliable and robust method for embedding and delivering complex insoluble chemotherapeutical molecules, and it is less invasive than other alternative methods in the literature.
CRIS-Team Scopus Importer:2022-10-14
Keywords: Controlled antineoplastic drug release; Hydrogel; Nanocarriers; Topical drug delivery system

Toughened and machinable glass matrix composites reinforced with graphene and graphene-oxide nano platelets - Porwal, Harshit; Tatarko, Peter; Grasso, Salvatore; Hu, Chunfeng; Boccaccini, Aldo R.; Dlouhy, Ivo; Reece, Mike J. (Science and Technology of Advanced Materials, 2013)
The processing conditions for preparing well dispersed silica-graphene nanoplatelets and silica-graphene oxide nanoplatelets (GONP) composites were optimized using powder and colloidal processing routes. Fully dense silica-GONP composites with up to 2.5 vol% loading were consolidated using spark plasma sintering. The GONP aligned perpendicularly to the applied pressure during sintering. The fracture toughness of the composites increased linearly with increasing concentration of GONP and reached a value of ∼0.9 MPa m 1/2 for 2.5 vol% loading. Various toughening mechanisms including GONP necking, GONP pull-out, crack bridging, crack deflection and crack branching were observed. GONP decreased the hardness and brittleness index (BI) of the composites by ∼30 and ∼50% respectively. The decrease in BI makes silica-GONP composites machinable compared to pure silica. When compared to silica-Carbon nanotube composites, silica-GONP composites show better process-ability and enhanced mechanical properties. © 2013 National Institute for Materials Science.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.toughe
Keywords: graphene/graphene-oxide nanoplatelets; mechanical properties; nanocomposites; silica; sintering

Toughening and functionalization of bioactive ceramic and glass bone scaffolds by biopolymer coatings and infiltration: a review of the last 5 years - Philippart, Anahi; Boccaccini, Aldo R.; Fleck, Claudia; Schubert, Dirk W.; Roether, Judith (Expert Review of Medical Devices, 2015)
Inorganic scaffolds with high interconnected porosity based on bioactive glasses and ceramics are prime candidates for applications in bone tissue engineering. These materials however exhibit relatively low fracture strength and high brittleness. A simple and effective approach to improve the toughness is to combine the basic scaffold structure with polymer coatings or through the formation of interpenetrating polymer-bioactive ceramic microstructures. The polymeric phase can additionally serve as a carrier for growth factors and therapeutic drugs, thus adding biological functionalities. The present paper reviews the state-of-the art in the field of polymer coated and infiltrated bioactive inorganic scaffolds. Based on the notable combination of bioactivity, improved mechanical properties and drug or growth factor delivery capability, this scaffold type is a candidate for bone and osteochondral regeneration strategies. Remaining challenges for the improvement of the materials are discussed and opportunities to broaden the application potential of this scaffold type are also highlighted.
Keywords: bioactive glasses; bioceramics; bone tissue engineering; calcium phosphates; composite materials; drug delivery; growth factors; hydroxyapatite; scaffolds

Toughening effects quantification in glass matrix composite reinforced by alumina platelets - Kotoul, M.; Pokluda, Jaroslav; Sandera, Pavel; Dlouhy, Ivo; Chlup, Zdenek; Boccaccini, Aldo R. (Acta Materialia, 2008)
A borosilicate glass matrix composite containing alumina platelets was considered to investigate toughening mechanisms and crack tip behavior in dispersion reinforced brittle matrix composites. Fracture toughness was determined by applying the chevron notched specimen technique, and fractographic analysis was employed to reveal the active toughening mechanisms with increasing content of reinforcement. A roughness-induced shielding effect has been quantified to prove the relation between fracture toughness and fracture surface roughness. Theoretical calculations of the fracture toughness enhancement based on a modified crack deflection model developed by Faber and Evans, combined with the influence of the increase in Young's modulus, were found to be in good agreement with experimental data. An effect of residual stresses upon toughening of the investigated composite is discussed. © 2008 Acta Materialia Inc.
UnivIS-Import:2015-03-09:Pub.2008.tech.IW.LM.toughe
Keywords: Crack deflection; Fracture surface roughness; Glass matrix composites; Residual stresses

Toward Highly Dispersed Mesoporous Bioactive Glass Nanoparticles With High Cu Concentration Using Cu/Ascorbic Acid Complex as Precursor - Zheng, Kai; Kang, Jeonil; Rutkowski, Bogdan; Gaweda, Magdalena; Zhang, Jue; Wang, You; Founier, Niklas; Sitarz, Maciej; Taccardi, Nicola; Boccaccini, Aldo R. (Frontiers in Chemistry, 2019)
Copper (Cu) ions have a variety of advantageous biological functionalities, such as proangiogenic and bactericidal activities. Given the intrinsic biodegradability and biocompatibility, silicate-based mesoporous bioactive glass nanoparticles (MBGNs) are considered as promising platforms for the delivery of Cu ions. However, effective incorporation of Cu into MBGNs still faces challenges, e.g., particle aggregation, the formation of insoluble crystalline Cu-based nanoparticles, and a low loading amount of Cu. We report a novel method to synthesize chemically homogenous and highly dispersed Cu-containing MBGNs (Cu-MBGNs) with tunable Cu concentration by using ascorbic acid/Cu complexes as the precursor of Cu in a microemulsion-assisted sol-gel approach. Cu-MBGNs exhibited a sphere-like shape with a particle size between 100 and 300 nm while their pore size varied from 2 to 10 nm. The inclusion of Cu, regardless of the incorporated concentration, did not significantly affect the morphology of particles. ICP-AES results indicated that the concentration of Cu in the particles could be conveniently tuned from 0 to similar to 6 mol% by controlling the amount of ascorbic acid/Cu complexes added, while the formation of crystalline Cu-based nanoparticles was avoided. The amorphous feature of Cu-MBGNs was proved by XRD, while the predominant oxidation state of Cu was evidenced to be Cu2+ by XPS. The incorporation of Cu did not inhibit the apatite-forming ability (bioactivity) of the particles in contact with simulated body fluid. Cu-MBGNs exhibited the capability of releasing Cu, Si, and Ca ions over time in the physiological fluid. The concentration of released Cu ions could be controlled by selecting specific Cu-MBGNs of different Cu contents. The dissolution products of most Cu-MBGNs at the dosage of 1, 0.1, and 0.01 mg/mL did not exhibit cytotoxicity, while only 7Cu-MBGN was cytotoxic at the dosage of 1 mg/mL. This study provided a feasible strategy to synthesize highly dispersed amorphous Cu-MBGNs with high Cu concentrations for biomedical applications. The particles exhibit great potential as building blocks for developing composite 3D scaffolds, coatings, and drug carriers, particularly when a large amount of particles incorporated may compromise the properties of (polymer) matrix materials while a relatively high concentration of released Cu ions is still required.
CRIS-Team WoS Importer:2019-08-02

Towards the synthesis of an Mg-containing silicate glass-ceramic to be used as a scaffold for cementum/alveolar bone regeneration - Goudouri, Ourania Menti; Kontonasaki, Eleana; Chrissafis, Konstantinos; Zinn, Kerstin; Hoppe, Alexander; Detsch, Rainer; Paraskevopoulos, Konstantinos M.; Boccaccini, Aldo R. (Ceramics International, 2014)
The gradual destruction of periodontal tissue and in particular the reduction of alveolar bone height which can ultimately lead to tooth loss is a common problem in patients suffering from periodontal disease. The aim of the present work was to investigate the sol-gel synthesis and characterization of a family of new Mg-containing bioactive silicate glasses for applications in cementum/alveolar bone regeneration. Their microstructural, biological and mechanical characteristics were optimized for the fabrication of functional bioceramic scaffolds using the foam replica technique. The optimal glass composition for periodontal tissue replacement was found to contain 60 mol% SiO, 30 mol% CaO and 10 mol% MgO. After sintering, this composition had enhanced mechanical properties combined with the desired apatite-forming ability, which was tested in simulated body fluid (SBF) for up to 5 days. In vitro analysis revealed positive effects of these scaffolds on bone marrow stromal cells.
Keywords: A. Powders: chemical preparation; C. Hardness; D. Glass-ceramics; D. Silicate; E. Biomedical applications

TRIS buffer in simulated body fluid distorts the assessment of glass-ceramic scaffold bioactivity - Rohanova, Dana; Boccaccini, Aldo R.; Yunos, Darmawati Mohamad; Horkavcova, Diana; Brezovska, Iva; Helebrant, Ales (Acta Biomaterialia, 2011)
The paper deals with the characterisation of the bioactive phenomena of glass-ceramic scaffold derived from Bioglass® (containing 77 wt.% of crystalline phases Na2O·2CaO·3SiO2 and CaO·SiO2 and 23 wt.% of residual glass phase) using simulated body fluid (SBF) buffered with tris-(hydroxymethyl) aminomethane (TRIS). A significant effect of the TRIS buffer on glass-ceramic scaffold dissolution in SBF was detected. To better understand the influence of the buffer, the glass-ceramic scaffold was exposed to a series of in vitro tests using different media as follows: (i) a fresh liquid flow of SBF containing tris (hydroxymethyl) aminomethane; (ii) SBF solution without TRIS buffer; (iii) TRIS buffer alone; and (iv) demineralised water. The in vitro tests were provided under static and dynamic arrangements. SBF buffered with TRIS dissolved both the crystalline and residual glass phases of the scaffold and a crystalline form of hydroxyapatite (HAp) developed on the scaffold surface. In contrast, when TRIS buffer was not present in the solutions only the residual glassy phase dissolved and an amorphous calcium phosphate (Ca-P) phase formed on the scaffold surface. It was confirmed that the TRIS buffer primarily dissolved the crystalline phase of the glass-ceramic, doubled the dissolving rate of the scaffold and moreover supported the formation of crystalline HAp. This significant effect of the buffer TRIS on bioactive glass-ceramic scaffold degradation in SBF has not been demonstrated previously and should be considered when analysing the results of SBF immersion bioactivity tests of such systems. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.trisbu
Keywords: Bioactive glass-ceramics; Dissolution; Scaffold; Simulated body fluid; TRIS buffer

Tuning of Cell-Biomaterial Anchorage for Tissue Regeneration - Leal-Egaña, Aldo; Diaz-Cuenca, Aranzazu; Boccaccini, Aldo R. (Advanced Materials, 2013)
Which mechanisms mediate cell attachment to biomaterials? What role does the surface charge or wettability play on cell-material anchorage? What are the currently investigated strategies to modify cell-matrix adherence spatiotemporally? Considering the development of scaffolds made of biocompatible materials to temporarily replace the structure and/or function of the extracellular matrix, focus is given to the analysis of the specific (i.e., cell adhesive peptide sequences) and unspecific (i.e., surface charge, wettability) mechanisms mediating cell-matrix interactions. Furthermore, because natural tissue regeneration is characterized by the dynamic attachment/detachment of different cell populations, the design of advanced scaffolds for tissue engineering, based in the spatiotemporal tuning of cell-matrix anchorage is discussed. Focus is given on the analysis of the specific and unspecific mechanisms mediating cell-matrix interactions. Furthermore, because natural tissue regeneration is characterized by the dynamic attachment/detachment of different cell populations, the advanced design of scaffolds for tissue engineering, based in the spatiotemporal tuning of cell-matrix anchorage, is discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.tuning
Keywords: cell adhesion; cell-matrix anchorage; spatiotemporal tuning; tissue engineering; tunable biomaterials

Ultrasonic Characterisation of Porous Biomaterials Across Different Frequencies - Kohlhauser, C.; Hellmich, C.; Vitale-Brovarone, C.; Boccaccini, Aldo R.; Rota, A.; Eberhardsteiner, Josef (Strain, 2009)
Mechanical testing is the most common experimental technique to determine elastic stiffness of materials. In case of porous materials, especially such with very high porosity, the determination of material stiffness may be strongly biased by inelastic deformations occurring in the material samples, especially in the vicinity of the load transfer devices, such as loading platens. In contrast, ultrasonic waves propagating through a material generate very small stresses and strains (and also strain rates lying in the 'quasistatic' regime). Thus, they enable the direct determination of the components of elastic stiffness tensors of materials, and also of those with a very high porosity. We shortly revisit from the theoretical basis of continuum (micro)mechanics that, depending on the frequency of the employed acoustical signals, the investigated materials are characterised at different observation scales, e.g. the elasticity of the overall porous medium, or that of the solid matrix inside the material are determined. We here report the elastic properties of biomaterials and biological materials at different length scales, by using ultrasound frequencies ranging from 100 kHz to 20 MHz. We tested isotropic scaffolds for biomedical engineering, made up of porous titanium and two different bioactive glass-ceramics, and we also determined the direction-dependent normal and shear stiffness components of the anisotropic natural composite 'spruce wood'. © 2009 The Authors.
UnivIS-Import:2015-03-09:Pub.2009.tech.IW.LM.ultras
Keywords: Porous biomaterials; Stiffness tensor components; Ultrasound; Wood

Ultrasonic elasticity determination of 45S5 Bioglass®-based scaffolds: Influence of polymer coating and crosslinking treatment - Li, Wei; Pastrama, Maria-Ioana; Ding, Yaping; Zheng, Kai; Hellmich, Christian; Boccaccini, Aldo R. (Journal of the Mechanical Behavior of Biomedical Materials, 2014)
Highly porous 45S5 Bioglass-based scaffolds with interconnected pore structure are promising candidates for bone tissue engineering due to their bioactivity, biocompatibility, osteogenic and angiogenic effects. In the present study, to ensure the mechanical competence of the 45S5 Bioglass-based scaffolds, their stiffness was adjusted by applying polymer coatings and further crosslinking treatment. A non-destructive ultrasonic technique was used to determine the stiffness of the scaffolds. The stiffness of uncoated scaffolds was shown to increase by applying polymer coatings, and a further increase was achieved by crosslinking the used polymer coatings. All uncoated and polymer-coated scaffolds were confirmed to exhibit stiffness values in the range of reported values in the literature for cancellous bone. A statistical evaluation of combined multiscale ultrasound-nanoindentation measurements indicated that the stiffness of the coated scaffold is directly dependent on the stiffness of the polymer coating.
Keywords: Bioglass®; Elasticity; Polymer coating; Scaffold; Ultrasound

Ultrasound identification of nerve cords in the infraclavicular fossa: a clinical study. - Di Filippo, Alessandro; Orando, S.; Luna, A.; Gianesello, L.; Boccaccini, Aldo R.; Campolo, M. C.; De Gaudio, A. R. (Minerva anestesiologica, 2012)
BACKGROUND This study aimed to analyze nerve trunk anatomy in the infraclavicular fossa and to correlate these data with the most common anthropometric parameters. METHODS A Mylab 30 Gold (Esaote) and the linear transducer LA523 (7.5 MHz frequency) were used. The probe was oriented according to a parasagittal plane, parallel to the lateral chest wall and immediately medial to the coracoid process underneath the clavicle. Measurements included the distance between the artery and the cutaneous surface (mm) and the apical corner of the ultrasound image (mm), the number of identified nervous cords and their position related to the axillary artery, and the position and number of axillary veins. Sex, age, height, weight, body mass index (BMI), biceps girth, and breast size were recorded. Statistical analysis included calculation of linear Pearson correlation coefficient and Student's t test. RESULTS Two hundred and two consecutive patients were enrolled. The position of the three cords was highly variable around the artery. In a small but significant percentage of patients (8.9%), the medial and the lateral cords were located together at the top of the artery. The visibility of the trunks and the distance between the upper part of the artery and the apical corner of the ultrasound image correlated with anthropometric characteristics. The vein position with respect to the artery and nerves was markedly variable. CONCLUSION Sono-anatomic study of the infraclavicular region adds important data that is useful when conducting nerve blocks to improve safety and likelihood of success.

Understanding bioactive glass powder Suspensions for electrophoretic deposition of bioactive glass-polymer coatings - Cabanas Polo, Sandra; Boccaccini, Aldo R. (Journal of The Electrochemical Society, 2015)
Suspensions of bioactive glass (BG) powder (45S5 composition) in water/ethanol mixtures (from 0 to 100 vol.% of ethanol) intended for electrophoretic deposition (EPD) have been studied focusing on the effects of zeta potential on colloidal stability. The interactions between the negatively charged BG particles in a 20 vol.% ethanol suspension containing different polymers (synthetic polymers such as polyvinylpyrrolidone, polyethilenimine, polyacrylic acid and polyvinyl alcohol, as well as natural polymers such as chitosan and alginate) were established in order to investigate the colloidal behavior of BG particles as a function of polymer functional groups. It was found that both the chemical nature of the polymer (anionic, neutral or cationic) and the configuration of the polymer chain play important roles on the stabilization mechanism of BG particles. In addition, the optimal polymer content which is required to obtain homogeneous and reproducible coatings by EPD was studied for the mentioned synthetic polymers and the resulting coatings were characterized in terms of microstructure and composition. The bioactivity of selected coatings was evaluated by immersion in simulated body fluid.

Understanding the colloidal behaviour or 45S5 bioactive glass particles to obtain bioactive-glass based composite coatings by EPD - Cabanas Polo, Sandra; Boccaccini, Aldo R. (Key Engineering Materials, 2015)
The interaction between bioactive glass particles and polymers with different functional groups has been established in this work to better understand and control the colloidal processing of the bioactive glass phase. Cationic polyvinylpyrrolidone (PVP), anionic polyacrylic acid (PAA) and neutral polyvinyl alcohol (PVA) were selected and the surface reactions in alcoholic media and between bioactive glass particles and polymers were considered. All three polymers were successfully employed to obtain soft composite coatings incorporating bioactive glass particles.
Keywords: Bioactive glass; Colloidal stability; EPD; Synthetic polymer

Uniform Surface Modification of 3D Bioglass(®)-Based Scaffolds with Mesoporous Silica Particles (MCM-41) for Enhancing Drug Delivery Capability - Boccardi, Elena; Philippart, Anahi; Juhasz-Bortuzzo, Judith; Beltrán, Ana Maria; Novajra, Giorgia; Vitale-Brovarone, Chiara; Spiecker, Erdmann; Boccaccini, Aldo R. (Frontiers in Bioengineering and Biotechnology, 2015)
The design and characterization of a new family of multifunctional scaffolds based on bioactive glass (BG) of 45S5 composition for bone tissue engineering and drug delivery applications are presented. These BG-based scaffolds are developed via a replication method of polyurethane packaging foam. In order to increase the therapeutic functionality, the scaffolds were coated with mesoporous silica particles (MCM-41), which act as an in situ drug delivery system. These sub-micron spheres are characterized by large surface area and pore volume with a narrow pore diameter distribution. The solution used for the synthesis of the silica mesoporous particles was designed to obtain a high-ordered mesoporous structure and spherical shape – both are key factors for achieving the desired controlled drug release. The MCM-41 particles were synthesized directly inside the BG-based scaffolds, and the drug-release capability of this combined system was evaluated. Moreover, the effect of MCM-41 particle coating on the bioactivity of the BG-based scaffolds was assessed. The results indicate that it is possible to obtain a multifunctional scaffold system characterized by high and interconnected porosity, high bioactivity, and sustained drug delivery capability.
Keywords: ordered mesoporosity; silica; MCM-41; bioactive glass; scaffolds; drug release; ibuprofen

Up-cycling of iron-rich inorganic waste in functional glass-ceramics - Romero, Acacio Rincón; Desideri, Daniele; Boccaccini, Aldo R.; Bernardo, Enrico (Minerals, 2020)
The intensive mechanical stirring of suspensions of recycled glass and inorganic waste powders in ‘weakly alkaline’ aqueous solutions (e.g., 2.5-3 NaOH), followed by viscous flow sintering at 800-1000 °C, easily yields highly porous glass-ceramic foams. The firing determines just the consolidation of powders with concurrent incorporation of pollutants from iron-rich waste, such as fly ash from coal combustion (FA). Engineered mixtures allow for the obtainment of chemically stable foams from treatments in air. Treatments in nitrogen are even more significant since they extend the conditions for stabilization and promote novel functionalities. In addition, the change in the atmosphere favors the formation of magnetite (Fe3O4), in turn enabling ultra-high dielectric permittivity and semiconductivity. Such a condition was further evidenced by preliminary tests on recycled glass combined with residues from the Bayer processing of aluminum ores or red mud (RM).
CRIS-Team Scopus Importer:2020-11-13
Keywords: Alkaline activation; Cellular ceramics; Electrical functionalities; Gel casting; Glass-ceramics; Viscous flow sintering

Up-cycling waste glass to minimal water adsorption/absorption lightweight aggregate by rapid low temperature sintering: Optimization by dual process-mixture response surface methodology - Velis, Costas A.; Franco-Salinas, Claudia; O'Sullivan, Catherine; Najorka, Jens; Boccaccini, Aldo R.; Cheeseman, Christopher R. (Environmental Science & Technology, 2014)
Mixed color waste glass extracted from municipal solid waste is either not recycled, in which case it is an environmental and financial liability, or it is used in relatively low value applications such as normal weight aggregate. Here, we report on converting it into a novel glass-ceramic lightweight aggregate (LWA), potentially suitable for high added value applications in structural concrete (upcycling). The artificial LWA particles were formed by rapidly sintering (<10 min) waste glass powder with clay mixes using sodium silicate as binder and borate salt as flux. Composition and processing were optimized using response surface methodology (RSM) modeling, and specifically (i) a combined process-mixture dual RSM, and (ii) multiobjective optimization functions. The optimization considered raw materials and energy costs. Mineralogical and physical transformations occur during sintering and a cellular vesicular glass-ceramic composite microstructure is formed, with strong correlations existing between bloating/shrinkage during sintering, density and water adsorption/absorption. The diametrical expansion could be effectively modeled via the RSM and controlled to meet a wide range of specifications; here we optimized for LWA structural concrete. The optimally designed LWA is sintered in comparatively low temperatures (825-835 °C), thus potentially saving costs and lowering emissions; it had exceptionally low water adsorption/absorption (6.1-7.2% w/w; optimization target: 1.5-7.5% w/w); while remaining substantially lightweight (density: 1.24-1.28 g.cm; target: 0.9-1.3 g.cm). This is a considerable advancement for designing effective environmentally friendly lightweight concrete constructions, and boosting resource efficiency of waste glass flows. © 2014 American Chemical Society.

Use of DC Plasma Treated Air Pollution Control (APC) Residue Glass as Pozzolanic Additive in Portland Cement - Kourti, Ioanna; Deegan, David; Boccaccini, Aldo R.; Cheeseman, Christopher R. (Waste and Biomass Valorization, 2013)
Air pollution control (APC) residues are hazardous waste generated from the air pollution abatement systems operating at energy from waste plants processing municipal solid waste. APC residues can be blended with glass forming additives and treated by direct current (DC) plasma technology, producing a stable, non-hazardous inert glass slag. This research has characterised the pozzolanic activity of this glass slag. The effects of glass cooling rate (quenched or air cooled) and particle size distribution have been investigated. The results show that quenched or fritted APC glass is significantly more pozzolanic than air-cooled glass. The optimum blended Portland cement paste, which maximises APC glass utilization and has the best properties, contained 20 wt % fritted APC glass slag. This blended Portland cement paste had low water demand, developed a dense microstructure and had high compressive strength (*100 MPa). The research has demonstrated that the glass slag resulting from DC plasma treatment of APC residues is pozzolanic and has potential to be beneficially reused in blended cements. © Springer Science+Business Media Dordrecht 2013.
UnivIS-Import:2015-03-09:Pub.2013.tech.IW.LM.useofd
Keywords: APC residues; DC plasma treatment; Energy from waste; Pozzolanic materials

Using Copper-Doped Mesoporous Bioactive Glass Nanospheres to Impart Anti-Bacterial Properties to Dental Composites - Munir, Arooj; Marovic, Danijela; Nogueira, Liebert Parreiras; Simm, Roger; Naemi, Ali-Oddin; Landro, Sander Marius; Helgerud, Magnus; Zheng, Kai; Par, Matej; Taubock, Tobias T.; Attin, Thomas; Tarle, Zrinka; et al. (Pharmaceutics, 2022)
Experimental dental resin composites containing copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) were developed to impart anti-bacterial properties. Increasing amounts of Cu-MBGN (0, 1, 5 and 10 wt%) were added to the BisGMA/TEGDMA resin matrix containing micro- and nano-fillers of inert glass, keeping the resin/filler ratio constant. Surface micromorphology and elemental analysis were performed to evaluate the homogeneous distribution of filler particles. The study investigated the effects of Cu-MBGN on the degree of conversion, polymerization shrinkage, porosity, ion release and anti-bacterial activity on S. mutans and A. naeslundii. Experimental materials containing Cu-MBGN showed a dose-dependent Cu release with an initial burst and a further increase after 28 days. The composite containing 10% Cu-MBGN had the best anti-bacterial effect on S. mutans, as evidenced by the lowest adherence of free-floating bacteria and biofilm formation. In contrast, the 45S5-containing materials had the highest S. mutans adherence. Ca release was highest in the bioactive control containing 15% 45S5, which correlated with the highest number of open porosities on the surface. Polymerization shrinkage was similar for all tested materials, ranging from 3.8 to 4.2%, while the degree of conversion was lower for Cu-MBGN materials. Cu-MBGN composites showed better anti-bacterial properties than composites with 45S5 BG.
CRIS-Team Scopus Importer:2022-11-11
Keywords: anti-bacterial; bioactive glass; copper; dental; mesoporous; nanoparticle; resin composites

Using electrophoretic deposition to edentify protein charge in biological medium - Boccaccini, Aldo R.; et al. (Journal of Applied Electrochemistry, 2011)
UnivIS-Import:2015-03-09:Pub.2011.tech.IW.LM.usinge_0

Vascularisation for cardiac tissue engineering: the extracellular matrix - Patra, Chinmoy; Boccaccini, Aldo R.; Engel, Felix (Thrombosis and Haemostasis, 2015)
Cardiovascular diseases present a major socio-economic burden. One major problem underlying most cardiovascular and congenital heart diseases is the irreversible loss of contractile heart muscle cells, the cardiomyocytes. To reverse damage incurred by myocardial infarction or by surgical correction of cardiac malformations, the loss of cardiac tissue with a thickness of a few millimetres needs to be compensated. A promising approach to this issue is cardiac tissue engineering. In this review we focus on the problem of in vitro vascularisation as implantation of cardiac patches consisting of more than three layers of cardiomyocytes (>100 mu m thick) already results in necrosis. We explain the need for vascularisation and elaborate on the importance to include non-myocytes in order to generate functional vascularised cardiac tissue. We discuss the potential of extracellular matrix molecules in promoting vascularisation and introduce nephronectin as an, example of a new promising candidate. Finally, we discuss current biomaterial-based approaches including micropatterning, electrospinning, 3D micro-manufacturing technology and porogens. Collectively, the current literature supports the notion that cardiac tissue engineering is a realistic option for future treatment of paediatric and adult patients with cardiac disease.
Keywords: Heart; vascularisation; coronary vasculature; tissue engineering; extracellular matrix

Vascular Tissue Engineering: Effects of Integrating Collagen into a PCL Based Nanofiber Material - Bertram, Ulf; Steiner, Dominik; Poppitz, Benjamin; Dippold, Dirk; Köhn, Katrin; Beier, Justus; Detsch, Rainer; Boccaccini, Aldo R.; Schubert, Dirk W.; Horch, Raymund E.; Arkudas, Andreas (BioMed Research International, 2017)
The engineering of vascular grafts is a growing field in regenerative medicine. Although numerous attempts have been made, the current vascular grafts made of polyurethane (PU), Dacron (R), or Teflon (R) still display unsatisfying results. Electrospinning of biopolymers and native proteins has been in the focus of research to imitate the extracellular matrix (ECM) of vessels to produce a small caliber, off-the-shelf tissue engineered vascular graft (TEVG) as a substitute for poorly performing PU, Dacron, or Teflon prostheses. Blended poly-epsilon-caprolactone (PCL)/collagen grafts have shown promising results regarding biomechanical and cell supporting features. In order to find a suitable PCL/collagen blend, we fabricated plane electrospun PCL scaffolds using various collagen type I concentrations ranging from 5% to 75%. We analyzed biocompatibility and morphological aspects in vitro. Our results show beneficial features of collagen I integration regarding cell viability and functionality, but also adverse effects like the loss of a confluent monolayer at high concentrations of collagen. Furthermore, electrospun PCL scaffolds containing 25% collagen I seem to be ideal for engineering vascular grafts.

Vaterite deposition on biodegradable polymer foam scaffolds for inducing bone-like hydroxycarbonate apatite coatings - Boccaccini, Aldo R.; et al. (Journal of Materials Science: Materials in Medicine, 2007)
Hydroxycarbonate apatite (HCA) coatings on the surface of bioresorbable materials for bone tissue engineering scaffolds were produced using macroporous poly(DL-lactide) (PDLLA) foams impregnated by calcium carbonate in vaterite crystalline form. Stable and homogeneous vaterite deposition on PDLLA foams was achieved using a slurry dipping technique. In vitro studies in simulated body fluid (SBF) were performed to induce formation of (HCA) on the surface of vaterite/PDLLA composite foams. HCA was detected after immersion of foams in SBF for 7 days. Hence, depositing vaterite on materials followed by immersion in SBF is confirmed to induce HCA coatings on the surface of the material. The HCA coated, bioactive and resorbable PDLLA foams are intended for use as bone tissue engineering scaffolds. © 2007 Springer Science+Business Media, LLC.
UnivIS-Import:2015-03-09:Pub.2007.tech.IW.LM.vateri

Verarbeitungstechnologien für Geopolymere: 3D-Druck und mechanische Bearbeitung - Toniolo, Nicoletta; Bednarzig, Vera; Roether, Judith; Rost, Harald; Boccaccini, Aldo R. (Keramische Zeitschrift, 2019)
CRIS-Team Scopus Importer:2019-06-21

Versatile bioactive and antibacterial coating system based on silica, gentamicin, and chitosan: Improving early stage performance of titanium implants - Ballarre, Josefina; Aydemir, T.; Liverani, Liliana; Roether, Judith; Goldmann, Wolfgang; Boccaccini, Aldo R. (Surface & Coatings Technology, 2019)
The aim of this work is to develop and characterize a multifunctional and dual surface coating system for titanium orthopedic implants by applying two different cost-effective, scalable, and non-complex coating technologies (spray and electrophoretic deposition). The first deposit is formed by a sprayed hybrid sol-gel layer combined with bioactive glass particles (45S5, BG), and the outer part of the dual coating consists of a chitosan-gelatin/silica (Si) - antibiotic (gentamicin, Ge) composite layer applied by electrophoretic deposition. The application of sol-gel enclosed BG drops onto the surface was done to enhance the bioactivity of the double-layered surface coating system. After the BG is dissolved, thus generating a calcium‑silicon rich medium, the re-deposition of hydroxyl‑carbonate apatite occurs. Regarding the antibacterial inhibition properties, antibacterial activity to both strains used (S. aureus and E. coli) was obtained for the chitosan/gelatin/Si[sbnd]Ge nanoparticle coatings on titanium substrates, showing a large inhibition area around the samples. Both the bare Ti samples and the coatings with chitosan/gelatin matrix did not successfully inhibit bacterial growth. As expected, the presence of silica-based glasses and coatings based on amorphous silica enhanced cell viability. The deposition of BG was done with the aim of extending the bioactive effect of the system, considering the presence of a porous degradable organic layer deposited on top, which was shown to be partially degraded after 7 days. The sol gel sprayed BG layer combined with chitosan/gelatin biopolymers filled with Si[sbnd]Ge nanoparticles presents a suitable technology to generate bioactive and antibacterial surfaces to enhance Ti implant performance.
CRIS-Team Scopus Importer:2019-12-13
Keywords: Antibacterial effect; Bioactive glass; Bioactivity; Electrophoretic deposition; Silica-gentamicin nanoparticles; Titanium

Versatile production of poly(Epsilon-caprolactone) fibers by electrospinning using benign solvents - Liverani, Liliana; Boccaccini, Aldo R. (Nanomaterials, 2016)
Keywords: Benign solvents; Bioactive glass; Composite; Electrospinning; Macroporosity; Nanofibers; Poly(epsilon-caprolactone)

Waste derived glass ceramic composites prepared by low temperature sintering/sinter-crystallisation - Ponsot, I.; Detsch, Rainer; Boccaccini, Aldo R.; Bernardo, Enrico (Advances in Applied Ceramics, 2015)
Glass-ceramics based on iron rich wastes were produced by direct sintering and by following an innovative approach, combining direct sintering and sinter-crystallisation processes. According to the second method, a layered tile was manufactured by single firing at 900 degrees C using a selected combination of wastes for both the porous body and the dense coating layer. The coating layer ('glaze') results from the sinter-crystallisation of a waste derived glass mixed with zircon and recycled borosilicate glass. The glaze sealed the porosity of the body and enhanced both mechanical properties and chemical stability. The results show a near to zero water absorption rate, despite a low geometric density (similar to 2 g cm(-3)), accompanied by a Young's modulus of similar to 40 GPa and a bending strength of similar to 30 MPa. The chemical stability of the glass-ceramics thus developed was assessed by the application of a toxicity control leaching procedure. Furthermore, cell culture tests were carried out to evaluate the potential cytotoxicity of the materials.
Keywords: Glass-ceramics; Metallurgical waste; Viscous flow sintering; Crystallisation; Cytotoxicity

When Electrospun Fiber Support Matters: In Vitro Ovine Long-Term Folliculogenesis on Poly (Epsilon Caprolactone) (PCL)-Patterned Fibers - Di Berardino, Chiara; Liverani, Liliana; Peserico, Alessia; Capacchietti, Giulia; Russo, Valentina; Bernabo, Nicola; Tosi, Umberto; Boccaccini, Aldo R.; Barboni, Barbara (Cells, 2022)
Current assisted reproduction technologies (ART) are insufficient to cover the slice of the population needing to restore fertility, as well as to amplify the reproductive performance of domestic animals or endangered species. The design of dedicated reproductive scaffolds has opened the possibility to better recapitulate the reproductive 3D ovarian environment, thus potentially innovating in vitro folliculogenesis (ivF) techniques. To this aim, the present research has been designed to compare ovine preantral follicles in vitro culture on poly(epsilon-caprolactone) (PCL)-based electrospun scaffolds designed with different topology (Random vs. Patterned fibers) with a previously validated system. The ivF performances were assessed after 14 days under 3D-oil, Two-Step (7 days in 3D-oil and on scaffold), or One-Step PCL protocols (14 days on PCL-scaffold) by assessing morphological and functional outcomes. The results show that Two- and One-Step PCL ivF protocols, when performed on patterned scaffolds, were both able to support follicle growth, antrum formation, and the upregulation of follicle marker genes leading to a greater oocyte meiotic competence than in the 3D-oil system. In conclusion, the One-Step approach could be proposed as a practical and valid strategy to support a synergic follicle-oocyte in vitro development, providing an innovative tool to enhance the availability of matured gametes on an individual basis for ART purposes.
CRIS-Team WoS Importer:2022-07-08

When Mechanical Stress Matters: Generation of Polyploid Giant Cancer Cells in Tumor-Like Microcapsules - Antonelli, Yasmin; Krüger, René; Bühler, Adrian; Monavari, Mahshid; Fuentes Chandia, Miguel Angel; Colombo, Federico; Palmisano, Ralf; Boßerhoff, Anja Katrin; Kappelmann-Fenzl, Melanie; Schödel, Johannes; Boccaccini, Aldo R.; Selhuber-Unkel, Christine; et al. (Advanced Functional Materials, 2024)
Biofabrication techniques enable the performance of bioinspired three-dimensional (3D) matrices resembling primary tumors. To validate their reliability, embedded cells may express complex biophysical responses. Among others, the emergence of tumor heterogeneity and the generation of Polyploid Giant Cancer Cells (PGCC), as a result of the mechanical stress, are two of the most challenging hallmarks to resemble in vitro. Here, these phenomena are studied in cells cultured on two-dimensional (2D) flasks, in 3D spheroids, or immobilized within 3D polymer-based tumor-like microcapsules. These results show that cells cultured in 3D microcapsules exhibited an enhanced biomechanical heterogeneity, a higher number of PGCC, and an increased exertion of cell-matrix attachment forces with respect to the other two experimental conditions. Additionally, cells isolated from tumor-like microcapsules redistribute and align the cytoplasmatic protein Caveolin-1, and upregulate markers involved in cell proliferation (i.e., Ki67), metastasis (i.e., TGF-β1, TGF-β-R2), and epithelial to mesenchymal transition, to name a few. These hallmarks are barely described in the past as a result of the confinement and mechanical stress. Thus, in this work it is demonstrated that both the mechanical stress and confinement are required to stimulate cell polyploidy and biomechanical heterogeneity, which can be easily addressed by immobilizing breast cancer cells in tumor-like microcapsules.
CRIS-Team Scopus Importer:2024-02-16
Keywords: 3D cell culture; cancer biomechanics; intratumor heterogeneity; Polyploid giant cancer cells; Tumor-like microcapsules

Zein-based composites in biomedical applications - Demir, Merve; Ramos Rivera, Laura; Silva, Raquel; Nazhat, Showan Najdat; Boccaccini, Aldo R. (Journal of Biomedical Materials Research Part A, 2017)
Considerable research efforts have been devoted to zein-based biomaterials for tissue engineering and other biomedical applications over the past decade. The attention given to zein-based polymers is primarily attributed to their biocompatibility and biodegradability. However, due to the relatively low mechanical properties of these polymers, numerous inorganic compounds (e.g., hydroxyapatite, calcium phosphate, bioactive glasses, natural clays) have been considered in combination with zein to create composite materials in an attempt to enhance zein mechanical properties. Inorganic phases also positively impact on the hydrophilic properties of zein matrices inducing a suitable environment for cell attachment, spreading, and proliferation. This review covers available literature on zein and zein-based composite materials, with focus on the combination of zein with commonly used inorganic fillers for tissue engineering and drug delivery applications. An overview of the most recent advances in fabrication techniques for zein-based composites is presented and key applications areas and future developments in the field are highlighted
Keywords: zein; composi tes; scaffolds; bone tissue engin eering

Zein-Based Electrospun Fibers Containing Bioactive Glass with Antibacterial Capabilities - Mariotti, Camilla E.; Ramos Rivera, Laura; Conti, Bice; Boccaccini, Aldo R. (Macromolecular Bioscience, 2020)
Zein, a natural protein from corn, has important applications in food and pharmaceutical industries due the fact that it is biodegradable and biocompatible. However, due its relatively low mechanical properties and water solubility, many inorganic compounds (e.g., bioactive glasses [BGs]) have been used in combination with zein to obtain composite materials with improved mechanical properties. Such inorganic additions provide further biological functionality to zein. In this work, fiber mats of zein with incorporation of BG and copper doped BG particles are successfully obtained by electrospinning. At first the electrospinnability of the blends is assessed, then the morphological and chemical characterization of the mats is done. Degradation study in cell culture medium (Dubelcco’s modified Eagle’s medium) reveals a sufficient strength of the fibers, which in turn is necessary for in vitro cellular studies. Cell culture studies using MG-63 and C2C12 cells show promising results, demonstrating increased cell proliferation and growth for fiber mats containing both types of BGs. Also, evaluation with Staphylococcus aureus and Escherichia coli bacteria confirms the antibacterial activity of the scaffolds containing copper. The presence of Cu thus imparts antibacterial properties without influencing cell behavior. The developed electrospun fibers represent a novel scaffold system for tissue engineering applications.
CRIS-Team Scopus Importer:2020-06-05
Keywords: antibacterial effect; bioactive glass; copper; electrospinning; zein

Zellgewebe aus dem Drucker - Schacht, Kristin; Jüngst, Tomasz; Zehnder, Tobias; Boccaccini, Aldo R.; Groll, Jürgen; Scheibel, Thomas (Nachrichten aus der Chemie, 2016)
Die Biofabrikation, also die Verarbeitung von Biotinte, baut mit zellfreundlichen 3-D-Druckverfahren gewebeartige Strukturen auf. Die Zusammensetzung von Biotinten steht daher im Fokus der Materialentwickler, die Gewebe züchten.<br
CRIS-Team Scopus Importer:2022-08-05

Zinc-containing bioactive glasses for bone regeneration, dental and orthopedic applications - Balasubramanian, Preethi; Strobel, Leonie; Kneser, Ulrich; Boccaccini, Aldo R. (Biomedical Glasses, 2015)

Zinc improves antibacterial, anti-inflammatory and cell motility activity of chitosan for wound healing applications - Mutlu, Nurshen; Liverani, Liliana; Kurtuldu, Fatih; Galusek, Dušan; Boccaccini, Aldo R. (International Journal of Biological Macromolecules, 2022)
We report the successful preparation and characterization of chitosan-Zn complex (ChiZn) in the form of films, intended to enhance the biological performance of chitosan by the presence of Zn as antibacterial agent and biologically active ion. The influence of Zn chelation on morphology and structure of chitosan was assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and infrared spectroscopy. The biodegradability study of ChiZn showed a sustained release of Zn up to 2 mg/mL. No toxic response was observed toward stromal cell line ST-2 in indirect contact with the ChiZn films. The dissolution product of ChiZn showed improved wound closure (88% closure) compared to the positive control group (70% closure). Moreover, ChiZn exhibited antibacterial activity against S. aureus together with a slight increase ( 30%) in the secretion of VEGF and moderate decrease in nitric oxide evolution. Our findings indicate that ChiZn could be used as a safe and effective wound healing agent.<br
Keywords: Chitosan‑zinc complex; Chelation process; Wound healing; Antibacterial activity

Zn-Loaded and Calcium Phosphate-Coated Degradable Silica Nanoparticles Can Effectively Promote Osteogenesis in Human Mesenchymal Stem Cells - Sutthavas, Pichaporn; Schumacher, Matthias; Zheng, Kai; Habibovic, Pamela; Boccaccini, Aldo R.; Van Rijt, Sabine (Nanomaterials, 2022)
Nanoparticles such as mesoporous bioactive glasses (MBGs) and mesoporous silica nanoparticles (MSN) are promising for use in bone regeneration applications due to their inherent bioactivity. Doping silica nanoparticles with bioinorganic ions could further enhance their biological performance. For example, zinc (Zn) is often used as an additive because it plays an important role in bone formation and development. Local delivery and dose control are important aspects of its therapeutic application. In this work, we investigated how Zn incorporation in MSN and MBG nanoparticles impacts their ability to promote human mesenchymal stem cell (hMSC) osteogenesis and mineralization in vitro. Zn ions were incorporated in three different ways; within the matrix, on the surface or in the mesopores. The nanoparticles were further coated with a calcium phosphate (CaP) layer to allow pH-responsive delivery of the ions. We demonstrate that the Zn incorporation amount and ion release profile affect the nanoparticle's ability to stimulate osteogenesis in hMSCs. Specifically, we show that the nanoparticles that contain rapid Zn release profiles and a degradable silica matrix were most effective in inducing hMSC differentiation. Moreover, cells cultured in the presence of nanoparticle-containing media resulted in the highest induction of alkaline phosphate (ALP) activity, followed by culturing hMSC on nanoparticles immobilized on the surface as films. Exposure to nanoparticle-conditioned media did not increase ALP activity in hMSCs. In summary, Zn incorporation mode and nanoparticle application play an important role in determining the bioactivity of ion-doped silica nanoparticles.
CRIS-Team WoS Importer:2022-09-16

ZnO quantum dots modified bioactive glass nanoparticles with pH-sensitive release of Zn ions, fluorescence, antibacterial and osteogenic properties - Zheng, Kai; Lu, Miao; Rutkowski, Bogdan; Dai, Xinyi; Yang, Yuyun; Taccardi, Nicola; Stachewicz, Urszula; Czyrska-Filemonowicz, Aleksandra; Hueser, Norbert; Boccaccini, Aldo R. (Journal of Materials Chemistry B, 2016)

Zoledronic acid impregnated and poly (L-lactic acid) coated 45S5 Bioglass®-based scaffolds - Locs, Janis; Li, Wei; Sokolova, Marina; Roether, Judith; Loca, Dagnija; Boccaccini, Aldo R. (Materials Letters, 2015)
A new family of 45S5 Bioglass®-based scaffolds with local drug delivery capability was developed and characterized. The basic scaffold fabricated by the foam replica technique was impregnated with zoledronic acid and coated with poly(L-lactic acid) resulting in scaffolds with improved compressive strength in comparison with non-coated scaffolds and exhibiting the ability to deliver zoledronic acid in a controlled manner.
Keywords: Bioactive glass; Bisphosphonates; PLLA; Scaffolds