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Aldo R Boccaccini - One of the best experts on this subject based on the ideXlab platform.
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Electrophoretic deposition of chitosan/Bioglass® and chitosan/Bioglass®/TiO2 composite coatings for bioimplants
Ceramics International, 2016Co-Authors: Silvia Clavijo, Aldo R Boccaccini, Francisco Membrives, Gisela Alejandra Ramona Quiroga, María J. SantillánAbstract:Abstract Electrophoretic deposition (EPD) method has been developed for the fabrication of chitosan/Bioglass® and chitosan/Bioglass®/TiO2 composite coatings on stainless steel substrates for biomedical applications. Microstructure, thickness, and mechanical properties, such as Vickers microhardness, compressive strength, and elastic modulus were determined. The use of chitosan enabled the co-EPD of Bioglass® and TiO2 particles and offered the advantage of room temperature processing typical of EPD. The coating composition was varied by the combination of Bioglass® and TiO2 concentrations in the chitosan solutions used for EPD. The cathodic deposition yield was studied at constant voltage for various deposition times. The coatings were microstructurally characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy(EDS). Homogeneous chitosan/Bioglass® coatings on stainless steel substrates were obtained at constant voltage condition using aqueous suspensions based on 0.016 wt% chitosan and 2 wt% Bioglass®. The addition of TiO2 nanopowder to the composite coating was confirmed to improve the hardness, Young's modulus and compressive strength of the base chitosan/Bioglass® coating.
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Surface functionalization of Bioglass® with alkaline phosphatase
Surface and Coatings Technology, 2015Co-Authors: Enrica Verne, Sara Ferraris, Clara Cassinelli, Aldo R BoccacciniAbstract:Abstract Bioglass® type 45S5 is the most widespread bioactive glass studied for its inorganic bioactivity and ability to affect cell behaviour. In this research work sintered Bioglass® substrates were functionalized with a biological molecule (the enzyme alkaline phosphatase — ALP) in order to couple bioactive glass typical inorganic properties with biological signals. For the first time ALP grafting has been performed on the standard Bioglass® composition, which is the most widely bioactive glass studied and currently commercialized in various forms. ALP was grafted to sintered Bioglass® glass–ceramic pellets both via silanization and via direct bonding to hydroxyl groups exposed on the surface. The presence of the biomolecule was investigated by means of XPS and its activity by enzymatic activity test. In vitro bioactivity of sintered Bioglass® at different steps of the functionalization process was investigated by soaking samples in simulated body fluid (SBF) for various experimental times. The possibility to graft ALP in an active state on sintered Bioglass® 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® pellets is of interest as model for sintered Bioglass® derived scaffolds to be used in bone engineering.
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aging time and temperature effects on the structure and bioactivity of gel derived 45s5 glass ceramics
Journal of the American Ceramic Society, 2015Co-Authors: Kai Zheng, Showan N Nazhat, Anastasiia Solodovnyk, Ouraniamenti Goudouri, Christoph Stahli, Aldo R BoccacciniAbstract:Porous bioactive glass-ceramics based on the 45S5 Bioglass® composition were fabricated by an acid-catalyzed sol–gel method. The effects of aging time and temperature on the structure and in vitro bioactivity were investigated. Fourier-transform infrared spectroscopy (FTIR) was carried out on the samples to understand the structure and to monitor the formation of hydroxyapatite (HA) after immersion in simulated body fluid (SBF). The bioactivity of gel-derived 45S5 glass-ceramic and amorphous 45S5 Bioglass® was compared. The results showed that an increase in both aging time and temperature can enhance crystallization, whereas bioactivity is reduced with increasing aging time but not significantly influenced by aging temperature. Compared with amorphous 45S5 Bioglass®, gel-derived glass-ceramic aged for 3 d at 60°C exhibited a more rapid rate of HA formation after immersion for less than 7 d. Amorphous 45S5 Bioglass® showed higher HA formation rate after immersion in SBF for more than 7 d, whereas the quantity of formed HA on gel-derived 45S5 glass-ceramic was still comparable to that of amorphous 45S5 Bioglass® after immersion for 14 d. It is suggested that the lower bioactivity of 45S5 glass-ceramics could be outweighed by the higher surface area and higher content of Si–NBO groups in gel-derived glass-ceramics. The results thus confirm that gel-derived 45S5 glass-ceramic exhibiting bioactivity comparable to that of amorphous 45S5 Bioglass® can be fabricated by sol–gel method under suitable aging conditions.
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low temperature spark plasma sintering of 45s5 Bioglass
Journal of Non-crystalline Solids, 2013Co-Authors: Salvatore Grasso, Aldo R Boccaccini, R K Chinnam, Harshit Porwal, Michael J ReeceAbstract:Abstract 45S5 Bioglass® powder has been densified at low temperatures using Spark Plasma Sintering (SPS). By employing SPS with pressures ranging from 70 to 300 MPa, it was possible to achieve fully dense and completely amorphous 45S5 Bioglass® samples at temperatures as low as 500–550 °C. By increasing the sintering temperature up to 600 °C the dense samples crystallized to Na 2 CaSi 2 O 6 phase rather than Na 2 Ca 2 Si 3 O 9 which is usually achieved at higher temperature. Acellular in vitro test results in Simulated Body Fluid (SBF) revealed that SPSed samples sintered at 600 °C resulted in faster formation of hydroxyapatite compared to pressureless sintered ones (1050 °C), which were highly crystallized. Amorphous Bioglass® and/or Na 2 CaSi 2 O 6 phase prepared by SPS could potentially produce Bioglass® composites with increased bioactivity.
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three dimensional mineralization of dense nanofibrillar collagen Bioglass hybrid scaffolds
Biomacromolecules, 2010Co-Authors: Benedetto Marelli, Aldo R Boccaccini, Chiara E Ghezzi, Jake E Barralet, Showan N NazhatAbstract: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 ...
Aldo Roberto Boccaccini - One of the best experts on this subject based on the ideXlab platform.
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electrophoretic deposition of chitosan 45s5 Bioglass composite coatings for orthopaedic applications
Surface & Coatings Technology, 2011Co-Authors: F. Pishbin, Aldo Roberto Boccaccini, Abdolreza Simchi, Mary P. RyanAbstract:Abstract This article presents experimental results on the electrophoretic deposition (EPD) of bioresorbable chitosan/45S5 Bioglass® composite coatings for orthopaedic implants based on the Taguchi design of experiments (DOE) approach. The influence of EPD parameters including Bioglass® concentration, electric voltage and deposition time on deposition yield was studied by an orthogonal Taguchi array of L18 type. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition yield and its stability during constant-voltage EPD. The coatings were characterised by high resolution scanning electron microscope (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). It is shown that the co-deposition of polymer/Bioglass® system is very sensitive to the concentration of Bioglass® particles. The addition of Bioglass® to the chitosan suspension alters the deposition rate due to variation of pH, suspension conductivity, and zeta potential. For low Bioglass® concentrations, co-deposition of the chitosan and the bioactive glass particles occurs while at the higher concentrations massive deposition of the bioactive glass particles controls the deposition yield. The optimum condition for a high deposition rate with low standard deviation and homogeneous microstructure is achieved when an almost equal concentrations of chitosan and Bioglass® is utilized. The validity of the approach is shown by confirmation experiments at the predicted optimal condition, and the mechanism of electrophoretic co-deposition of the polymer/glass system is discussed.
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Electrophoretic deposition of chitosan/45S5 Bioglass® composite coatings for orthopaedic applications
Surface & Coatings Technology, 2011Co-Authors: F. Pishbin, Abdolreza Simchi, Mary P. Ryan, Aldo Roberto BoccacciniAbstract:Abstract This article presents experimental results on the electrophoretic deposition (EPD) of bioresorbable chitosan/45S5 Bioglass® composite coatings for orthopaedic implants based on the Taguchi design of experiments (DOE) approach. The influence of EPD parameters including Bioglass® concentration, electric voltage and deposition time on deposition yield was studied by an orthogonal Taguchi array of L18 type. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition yield and its stability during constant-voltage EPD. The coatings were characterised by high resolution scanning electron microscope (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). It is shown that the co-deposition of polymer/Bioglass® system is very sensitive to the concentration of Bioglass® particles. The addition of Bioglass® to the chitosan suspension alters the deposition rate due to variation of pH, suspension conductivity, and zeta potential. For low Bioglass® concentrations, co-deposition of the chitosan and the bioactive glass particles occurs while at the higher concentrations massive deposition of the bioactive glass particles controls the deposition yield. The optimum condition for a high deposition rate with low standard deviation and homogeneous microstructure is achieved when an almost equal concentrations of chitosan and Bioglass® is utilized. The validity of the approach is shown by confirmation experiments at the predicted optimal condition, and the mechanism of electrophoretic co-deposition of the polymer/glass system is discussed.
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Bioactivity of polyurethane-based scaffolds coated with Bioglass?
Biomedical Materials, 2007Co-Authors: Monika Bil, Judith A. Roether, Joanna Ryszkowska, Oana Bretcanu, Aldo Roberto BoccacciniAbstract:Polyurethane (PUR) and polyurethane/poly(d, l-lactide) acid (PUR/PDLLA) based scaffolds coated with Bioglass? particles for application in bone tissue engineering were fabricated. The slurry-dipping method was used for coating preparation. The homogeneous structure of the Bioglass? coatings on the surface of the PUR and PUR/PDLLA foams indicated a good adhesion of the bioactive glass particles to polyurethane without any additional surface treatment. In vitro studies in simulated body fluid (SBF) were performed to study the influence of Bioglass? coating on biodegrability and bioactivity of PUR-based scaffolds. The surface of Bioglass?-coated samples was covered by a layer of carbonate-containing apatite after 7 days of immersion in SBF, while in uncoated polymer samples apatite crystals were not detected even after 21 days of immersion in SBF. The apatite layer was characterized by scanning electron microscopy (SEM), EDS analysis and attenuated total reflectance?Fourier transform infrared spectrometry (FTIR?ATR). Weight loss measurements showed that the in vitro degradation rate of the composite scaffolds in SBF was higher in comparison to uncoated polyurethane samples. PUR and PUR/PDLLA foams with Bioglass? coating have potential to be used as bioactive, biodegradable scaffolds in bone tissue engineering.
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electrophoretic deposition of polyetheretherketone peek and peek Bioglass coatings on niti shape memory alloy wires
Journal of Materials Science, 2006Co-Authors: Aldo Roberto Boccaccini, Judith A. Roether, Dietmar Eifler, Superb K Misra, C Peters, E.j. MinayAbstract:Polyetheretherketone (PEEK) and PEEK/Bioglass® coatings were produced on shape memory alloy (NiTi, Nitinol®) wires using electrophoretic deposition (EPD). Best results were achieved with suspensions of PEEK powders in ethanol in the range (1–6 wt%), using a deposition time of 5 minutes and applied voltage of 20 Volts. EPD using these parameters led to high quality PEEK coatings with a homogeneous microstructure along the wire length and a uniform thickness of up to 15 μm without development of cracks or the presence of large voids. Suspensions of PEEK powders in ethanol with addition of Bioglass® particles (0.5–2 wt%) (size < 5 μm) were used to produce PEEK/Bioglass® coatings. Sintering was carried out as a post EPD process in order to densify the coatings and to improve the adhesion of the coatings to the substrate. The sintering temperature was 340 °C, sintering time 20 min and heating rate 300 °C/h. Sintering led to uniform and dense PEEK and PEEK/Bioglass® coatings without any cracks. The bioactive behaviour of PEEK/Bioglass® composite coatings was investigated by immersion in acellular simulated body fluid (SBF) for up to two weeks. As expected, hydroxyapatite crystals formed on the surface of the coated wires after 1 week in SBF, confirming the bioactive character of the coatings. The results have demonstrated for the first time that EPD is a very convenient method to obtain homogeneous and uniform bioactive PEEK and PEEK/Bioglass® coatings on Nitinol® wires for biomedical applications.
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Electrophoretic deposition of polyetheretherketone (PEEK) and PEEK/Bioglass® coatings on NiTi shape memory alloy wires
Journal of Materials Science, 2006Co-Authors: Aldo Roberto Boccaccini, Judith A. Roether, Dietmar Eifler, Superb K Misra, C Peters, E.j. MinayAbstract:Polyetheretherketone (PEEK) and PEEK/Bioglass® coatings were produced on shape memory alloy (NiTi, Nitinol®) wires using electrophoretic deposition (EPD). Best results were achieved with suspensions of PEEK powders in ethanol in the range (1–6 wt%), using a deposition time of 5 minutes and applied voltage of 20 Volts. EPD using these parameters led to high quality PEEK coatings with a homogeneous microstructure along the wire length and a uniform thickness of up to 15 μm without development of cracks or the presence of large voids. Suspensions of PEEK powders in ethanol with addition of Bioglass® particles (0.5–2 wt%) (size < 5 μm) were used to produce PEEK/Bioglass® coatings. Sintering was carried out as a post EPD process in order to densify the coatings and to improve the adhesion of the coatings to the substrate. The sintering temperature was 340 °C, sintering time 20 min and heating rate 300 °C/h. Sintering led to uniform and dense PEEK and PEEK/Bioglass® coatings without any cracks. The bioactive behaviour of PEEK/Bioglass® composite coatings was investigated by immersion in acellular simulated body fluid (SBF) for up to two weeks. As expected, hydroxyapatite crystals formed on the surface of the coated wires after 1 week in SBF, confirming the bioactive character of the coatings. The results have demonstrated for the first time that EPD is a very convenient method to obtain homogeneous and uniform bioactive PEEK and PEEK/Bioglass® coatings on Nitinol® wires for biomedical applications.
Judith A. Roether - One of the best experts on this subject based on the ideXlab platform.
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Bioactivity of polyurethane-based scaffolds coated with Bioglass?
Biomedical Materials, 2007Co-Authors: Monika Bil, Judith A. Roether, Joanna Ryszkowska, Oana Bretcanu, Aldo Roberto BoccacciniAbstract:Polyurethane (PUR) and polyurethane/poly(d, l-lactide) acid (PUR/PDLLA) based scaffolds coated with Bioglass? particles for application in bone tissue engineering were fabricated. The slurry-dipping method was used for coating preparation. The homogeneous structure of the Bioglass? coatings on the surface of the PUR and PUR/PDLLA foams indicated a good adhesion of the bioactive glass particles to polyurethane without any additional surface treatment. In vitro studies in simulated body fluid (SBF) were performed to study the influence of Bioglass? coating on biodegrability and bioactivity of PUR-based scaffolds. The surface of Bioglass?-coated samples was covered by a layer of carbonate-containing apatite after 7 days of immersion in SBF, while in uncoated polymer samples apatite crystals were not detected even after 21 days of immersion in SBF. The apatite layer was characterized by scanning electron microscopy (SEM), EDS analysis and attenuated total reflectance?Fourier transform infrared spectrometry (FTIR?ATR). Weight loss measurements showed that the in vitro degradation rate of the composite scaffolds in SBF was higher in comparison to uncoated polyurethane samples. PUR and PUR/PDLLA foams with Bioglass? coating have potential to be used as bioactive, biodegradable scaffolds in bone tissue engineering.
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electrophoretic deposition of polyetheretherketone peek and peek Bioglass coatings on niti shape memory alloy wires
Journal of Materials Science, 2006Co-Authors: Aldo Roberto Boccaccini, Judith A. Roether, Dietmar Eifler, Superb K Misra, C Peters, E.j. MinayAbstract:Polyetheretherketone (PEEK) and PEEK/Bioglass® coatings were produced on shape memory alloy (NiTi, Nitinol®) wires using electrophoretic deposition (EPD). Best results were achieved with suspensions of PEEK powders in ethanol in the range (1–6 wt%), using a deposition time of 5 minutes and applied voltage of 20 Volts. EPD using these parameters led to high quality PEEK coatings with a homogeneous microstructure along the wire length and a uniform thickness of up to 15 μm without development of cracks or the presence of large voids. Suspensions of PEEK powders in ethanol with addition of Bioglass® particles (0.5–2 wt%) (size < 5 μm) were used to produce PEEK/Bioglass® coatings. Sintering was carried out as a post EPD process in order to densify the coatings and to improve the adhesion of the coatings to the substrate. The sintering temperature was 340 °C, sintering time 20 min and heating rate 300 °C/h. Sintering led to uniform and dense PEEK and PEEK/Bioglass® coatings without any cracks. The bioactive behaviour of PEEK/Bioglass® composite coatings was investigated by immersion in acellular simulated body fluid (SBF) for up to two weeks. As expected, hydroxyapatite crystals formed on the surface of the coated wires after 1 week in SBF, confirming the bioactive character of the coatings. The results have demonstrated for the first time that EPD is a very convenient method to obtain homogeneous and uniform bioactive PEEK and PEEK/Bioglass® coatings on Nitinol® wires for biomedical applications.
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Electrophoretic deposition of polyetheretherketone (PEEK) and PEEK/Bioglass® coatings on NiTi shape memory alloy wires
Journal of Materials Science, 2006Co-Authors: Aldo Roberto Boccaccini, Judith A. Roether, Dietmar Eifler, Superb K Misra, C Peters, E.j. MinayAbstract:Polyetheretherketone (PEEK) and PEEK/Bioglass® coatings were produced on shape memory alloy (NiTi, Nitinol®) wires using electrophoretic deposition (EPD). Best results were achieved with suspensions of PEEK powders in ethanol in the range (1–6 wt%), using a deposition time of 5 minutes and applied voltage of 20 Volts. EPD using these parameters led to high quality PEEK coatings with a homogeneous microstructure along the wire length and a uniform thickness of up to 15 μm without development of cracks or the presence of large voids. Suspensions of PEEK powders in ethanol with addition of Bioglass® particles (0.5–2 wt%) (size < 5 μm) were used to produce PEEK/Bioglass® coatings. Sintering was carried out as a post EPD process in order to densify the coatings and to improve the adhesion of the coatings to the substrate. The sintering temperature was 340 °C, sintering time 20 min and heating rate 300 °C/h. Sintering led to uniform and dense PEEK and PEEK/Bioglass® coatings without any cracks. The bioactive behaviour of PEEK/Bioglass® composite coatings was investigated by immersion in acellular simulated body fluid (SBF) for up to two weeks. As expected, hydroxyapatite crystals formed on the surface of the coated wires after 1 week in SBF, confirming the bioactive character of the coatings. The results have demonstrated for the first time that EPD is a very convenient method to obtain homogeneous and uniform bioactive PEEK and PEEK/Bioglass® coatings on Nitinol® wires for biomedical applications.
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Bioglass?? coatings on biodegradable poly(3-hydroxybutyrate) (P3HB) meshes for tissue engineering scaffolds
Materialwissenschaft Und Werkstofftechnik, 2006Co-Authors: J. Olsen-claire, Aldo Roberto Boccaccini, Jonny James Blaker, Judith A. Roether, G. Schmack, K. GliescheAbstract:Osteoconduction and non-toxic bioresorbability can be achieved by combining Bioglass® particles and Poly (3-hydroxybutyrate) (P3HB) fibre meshes in novel composites for tissue engineering scaffolds. Bioglass® coatings readily induce hydroxyapatite (HA) formation on fibre surfaces in vitro, while biodegradable P3HB yields non toxic degradation products. In the present investigation, P3HB meshes were used, which were generated by means of an embroidery technology on the basis of yarns with 12 and 24 filaments with diameters of ∼ 30 μm. Bioglass® particles of average particle size < 5 μm were used to produce coatings on P3HB meshes by slurry dipping. By varying the concentration of Bioglass® particles in aqueous slurry, coating thickness and homogeneity could be controlled. Optimally coated meshes were incubated in simulated body fluid (SBF) for 3, 7, 14, and 21 days to detect formation of HA, as a qualitative assessment of bioactivity. Scanning electron microscopy (SEM) observations coupled with X-ray diffraction analyses revealed the presence of HA crystals on mesh surfaces following 3 days of incubation in SBF. The amount of HA crystals was shown to increase with incubation time in SBF. Minimal polymer degradation was seen after 21 days in SBF, suggesting a suitable time frame for tissue replacement. The novel Bioglass® /P3HB composite meshes developed here are potential materials for bone tissue engineering scaffold applications. Bioglass®-Beschichtungen auf bioloslichem Textilmaterial auf Basis von poly(3-hydroxybuttersaure) (P3HB) als Scaffolds fur Tissue-Engineering Osteoinduktion und nicht-toxische Bioloslichkeit kann durch die Kombinierung von Bioglass®-Teilchen und poly(3-hydroxybuttersaure) (P3HB)-Textilmaterial erreicht werden, um so neuartige Verbundwerkstoffe als Scaffolds fur Tissue-Engineering herzustellen. Bioglass®-Beschichtungen ermoglichen die Bildung von Hydroxylapatit (HA) auf der Oberflache der Fasern in vitro, wahrend das biolosliche P3HB resorbiert wird, ohne giftige Stoffe freizugeben. In dieser Studie wurden P3HB-Textilmaterialien benutzt, die mittels Stricktechnologie hergestellt wurden, mit Faden bestehend aus 12 and 24 Filamenten mit einem Durchmesser von ∼ 30 μm. Bioglass®-Teilchen mit einem durchschnittlichen Teilchendurchmesser von < 5μm wurden verwendet, um die P3HB Textilmaterialien mittels Tauchverfahren zu beschichten. Durch Variierung der Konzentration der Bioglass®-Teilchen in der wassrigen Losung konnte die Bioglass®-Schichtdicke und –homogenitat kontrolliert werden. Die optimierten Proben wurden fur 3, 7, 14 und 21 Tage in simulierte Korperflussigkeit (SBF) eingetaucht, um die Bildung von HA zu bestatigen, was als qualitativer Test der Bioaktivitat eines Materials benutzt werden kann. REM-Untersuchungen und Rontgenbeugungsanalyse (XRD) konnten die Bildung von HA-Kristallen auf der Oberflache des Textilmaterials nach 3 Tagen in SBF bestatigen. Die Menge der HA-Kristalle nahm mit zunehmender Zeit in SBF zu. Der Beginn von Polymerdegradierung konnte nach 21 Tagen in SBF nicht festgestellt werden, was darauf hinweist, dass die neuartigen Verbundwerkstoffe eine angemessene Loslichkeitzeit in SBF besitzen. Die neuartigen Bioglass® /P3HB Verbundwerkstoffe haben Potential als Konstrukte fur Anwendungen in Tissue- Engineering von Hartgewebe.
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assessment of polyglycolic acid mesh and bioactive glass for soft tissue engineering scaffolds
Biomaterials, 2004Co-Authors: Aldo R Boccaccini, Larry L. Hench, Judith A. Roether, Sandra Shurey, Alastair Forbes, S M GabeAbstract:Sufficient neovascularization of neotissue is currently a limiting factor for the engineering of large tissue constructs. 45S5 Bioglass has been investigated extensively in bone tissue engineering but there has been relatively little previous research on its application to soft-tissue engineering. The objectives of this study were to investigate the use of 45S5 Bioglass in soft-tissue engineering scaffolds using in vitro and in vivo models. A fibroblast cell line (208F) was used for in vitro evaluation of surfaces coated with 45S5 Bioglass. Increased proliferation of fibroblasts was observed after growth on polystyrene surfaces coated with low concentrations (0.01-0.2%wt/vol) of 45S5 Bioglass for 24 h in vitro, determined as a change in total cell number by measuring lactate dehydrogenase. At higher concentrations of 45S5 Bioglass and longer periods of incubation (48 and 72 h) on coated surfaces, cell proliferation was reduced. Light microscopy revealed that the morphology of fibroblasts grown on 45S5 Bioglass-coated surfaces was not altered at low concentrations, but at higher concentrations fibroblasts became vacuolated. Enzyme-linked immunosorbent assay of conditioned culture medium collected from fibroblasts grown for 24 h on surfaces coated with low concentrations of 45S5 Bioglass (0.01%wt/vol) was found to contain significantly higher concentrations of vascular endothelial growth factor. Histological examination of polyglycolic acid (PGA)/45S5 Bioglass composite scaffolds that had been implanted subcutaneously into rats revealed that 45S5 Bioglass-coated meshes were well tolerated. Light microscopy revealed that neovascularization into 45S5 Bioglass-coated meshes was significantly increased at 28 and 42 days. Electron microscopy revealed fibroblasts adhering closely to the PGA mesh but not to 45S5 Bioglass particles. The apparent ability of 45S5 Bioglass incorporated into scaffolds to increase neovascularization would be extremely beneficial during the engineering of larger soft-tissue constructs.
Larry L. Hench - One of the best experts on this subject based on the ideXlab platform.
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assessment of polyglycolic acid mesh and bioactive glass for soft tissue engineering scaffolds
Biomaterials, 2004Co-Authors: Aldo R Boccaccini, Larry L. Hench, Judith A. Roether, Sandra Shurey, Alastair Forbes, S M GabeAbstract:Sufficient neovascularization of neotissue is currently a limiting factor for the engineering of large tissue constructs. 45S5 Bioglass has been investigated extensively in bone tissue engineering but there has been relatively little previous research on its application to soft-tissue engineering. The objectives of this study were to investigate the use of 45S5 Bioglass in soft-tissue engineering scaffolds using in vitro and in vivo models. A fibroblast cell line (208F) was used for in vitro evaluation of surfaces coated with 45S5 Bioglass. Increased proliferation of fibroblasts was observed after growth on polystyrene surfaces coated with low concentrations (0.01-0.2%wt/vol) of 45S5 Bioglass for 24 h in vitro, determined as a change in total cell number by measuring lactate dehydrogenase. At higher concentrations of 45S5 Bioglass and longer periods of incubation (48 and 72 h) on coated surfaces, cell proliferation was reduced. Light microscopy revealed that the morphology of fibroblasts grown on 45S5 Bioglass-coated surfaces was not altered at low concentrations, but at higher concentrations fibroblasts became vacuolated. Enzyme-linked immunosorbent assay of conditioned culture medium collected from fibroblasts grown for 24 h on surfaces coated with low concentrations of 45S5 Bioglass (0.01%wt/vol) was found to contain significantly higher concentrations of vascular endothelial growth factor. Histological examination of polyglycolic acid (PGA)/45S5 Bioglass composite scaffolds that had been implanted subcutaneously into rats revealed that 45S5 Bioglass-coated meshes were well tolerated. Light microscopy revealed that neovascularization into 45S5 Bioglass-coated meshes was significantly increased at 28 and 42 days. Electron microscopy revealed fibroblasts adhering closely to the PGA mesh but not to 45S5 Bioglass particles. The apparent ability of 45S5 Bioglass incorporated into scaffolds to increase neovascularization would be extremely beneficial during the engineering of larger soft-tissue constructs.
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pdlla Bioglass composites for soft tissue and hard tissue engineering an in vitro cell biology assessment
Biomaterials, 2004Co-Authors: Sophie Verrier, Veronique Maquet, Larry L. Hench, Jonny James Blaker, Aldo R BoccacciniAbstract:Abstract The aim of this study was to examine the effect of increased content of 45S5 Bioglass® (0–40 wt%) in poly( dl -lactic acid) (PDLLA) porous foams on the behaviour of MG-63 (human osteosarcoma cell line) and A549 cells (human lung carcinoma cell line). The ability of these cell lines to grow on bioactive composites was quantitatively investigated in order to assess the potentiality for their use in hard and soft-tissue engineering. Two hours after cell seeding, an increase of cell adhesion according to the increased content of Bioglass® present in the foams for both cell types was observed. Cell proliferation studies performed over a period of 4 weeks showed a better aptitude of the A549 cells to proliferate on PDLLA foams containing 5 wt% Bioglass® when compared to the proliferation on foams with 40 wt% Bioglass®. A lower proliferation rate was obtained for cells on pure PDLLA. Scanning electron microscopy analysis showed for both cell types the presence of cells inside the porous structure of the foams. These results confirmed the biocompatibility of PDLLA/Bioglass® composite foams and the positive effect of Bioglass® on MG-63 cell behaviour and also showed for the first time the possibility for human lung epithelial type II cells to adhere and proliferate on these porous scaffolds. In addition, we describe a positive effect of 45S5 Bioglass® on A549 cell behaviour in a dose-dependent manner, indicating the potential of using PDLLA/Bioglass® composites with an optimal concentration of 45S5 Bioglass® not only in bone tissue engineering but also in lung tissue engineering.
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development and in vitro characterisation of novel bioresorbable and bioactive composite materials based on polylactide foams and Bioglass for tissue engineering applications
Biomaterials, 2002Co-Authors: Judith A. Roether, Veronique Maquet, Larry L. Hench, Aldo R Boccaccini, Sandrine Gautier, Robert JeromeAbstract:Abstract Bioactive and bioresorbable composite materials were fabricated using macroporous poly( dl -lactide) (PDLLA) foams coated with and impregnated by bioactive glass (Bioglass ® ) particles. Stable and homogeneous Bioglass ® coatings on the surface of PDLLA foams as well as infiltration of Bioglass ® particles throughout the porous network were achieved using a slurry-dipping technique in conjunction with pre-treatment of the foams in ethanol. The quality of the bioactive glass coatings was reproducible in terms of thickness and microstructure. Additionally, electrophoretic deposition was investigated as an alternative method for the fabrication of PDLLA foam/Bioglass ® composite materials. In vitro studies in simulated body fluid (SBF) were performed to study the formation of hydroxyapatite (HA) on the surface of PDLLA/Bioglass ® composites. SEM analysis showed that the HA layer thickness rapidly increased with increasing time in SBF. The high bioactivity of the PDLLA foam/Bioglass ® composites indicates the potential of the materials for use as bioactive, resorbable scaffolds in bone tissue engineering.
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Evaluation of Bioglass/dextran composite as a bone graft substitute.
International Journal of Oral and Maxillofacial Surgery, 2002Co-Authors: C. Chan, Ian Thompson, P. Robinson, J. Wilson, Larry L. HenchAbstract:Allogenic and alloplastic bone graft substitutes serve either as bioinert or bioactive osteoconductors. Bioglass is a bioactive osteoconductor and also shows osteoproductive effects due to its high level of bioactivity. However, the material lacks some cohesiveness when used in augmenting certain bony surfaces, i.e. large or pleomorphic defects. The addition of medium molecular weight dextran modifies the particulate to a putty consistency and improves the handling characteristics. The objective of this study is to evaluate the influence of dextran upon the bioactive properties of Bioglass. Standardized bony defects in the lateral femoral condyles in adult New Zealand white rabbits were filled with one of five material groups: (1) autogenous bone; (2) Bioglass particulate; (3) Bioglass particulate mixed with dextran to a putty-like consistency; (4) a mixture of Bioglass and autogenous bone; (5) a mixture of Bioglass putty with autogenous bone. Postoperative healing was observed after periods of 2 days, 1, 2, 3, 6 and 12 weeks. Results showed no evidence of toxicity in the dextran-containing materials, and defects in all test groups showed 100% bony ingrowth within 6 weeks. The addition of medium molecular weight dextran did not appear to alter the bioactive properties of Bioglass and had no adverse influence upon the ingrowth of bone into the defect sites.
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Bioglass high density polyethylene composite for soft tissue applications preparation and evaluation
Journal of Biomedical Materials Research, 1998Co-Authors: M Wang, Larry L. Hench, William BonfieldAbstract:Particulate 45S5 Bioglass® with an average size of 46 μm was incorporated into a high density polyethylene (HDPE) for potential medical applications. Composites with Bioglass® volumes of 10, 20, and 40% were produced by a manufacturing process consisting of blending, compounding, powdering, and compression molding. The Bioglass® particles were well dispersed, and their homogeneous distribution in the polymer matrix, achieved after compounding, was retained during subsequent composite processing. The Young's modulus and microhardness of the composites increased with an increase in Bioglass® volume while the tensile strength and fracture strain decreased. Fourier transform infrared spectra, obtained from Bioglass®/HDPE samples exposed for 20 h at 37°C to a simulated body fluid (SBF-9), demonstrated that composites of all the compositions examined developed the surface biological apatite layer equivalent to that for bulk Bioglass®. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 577–586, 1998.
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wetting of bioactive glass surfaces by poly α hydroxyacid melts interaction between Bioglass and biodegradable polymers
E-polymers, 2005Co-Authors: Jonny James Blaker, Veronique Maquet, Aldo R Boccaccini, Robert Jerome, Alexander BismarckAbstract:The interfacial characteristics between bioactive glass (45S5 Bioglass) surfaces and poly(α-hydroxyacid) melts have been assessed by direct wetting measurements. In particular, the wettability of Bioglass powder by poly(D,Llactide) (PDLLA) and poly(D,L-lactide-co-glycolide) (PLGA) was assessed by imbibition measurements. Additionally, the equilibrium contact angles of PDLLA and PLGA melts on a sintered Bioglass surface were measured. The surface energy of the bioactive glass and the polymers was determined from contact angles measured using various test liquids on PDLLA, PLGA and Bioglass solid substrates. There are sufficient adhesive interactions between the polymers and Bioglass. A simple heat treatment of the bioactive glass in an inert gas atmosphere leads to an improved wetting behaviour, indicating increased adhesive interactions. Scanning electron micrographs of the polymer + Bioglass composites formed by polymer penetration into the powder bed show the formation of a ‘good quality’ interface.
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preparation and characterisation of poly lactide co glycolide plga and plga Bioglass composite tubular foam scaffolds for tissue engineering applications
Materials Science and Engineering: C, 2005Co-Authors: Aldo R Boccaccini, Veronique Maquet, Jonny James Blaker, Robert JeromeAbstract:Abstract Polylactide-co-glycolide (PLGA) and PLGA/Bioglass® foams of tubular shape have been prepared with a 1 wt.% 45S5 Bioglass® content. Porous membranes with varying thickness and porosity were fabricated via a thermally induced phase separation process, from which tubes of controlled diameter and wall thickness in the range 1.5–3 mm were produced. Scanning electron microscopy (SEM) revealed that the structure of the tubular foams consisted of radially oriented and highly interconnected pores with two distinct pore sizes, i.e. macropores ∼100-μm average diameter and interconnected micropores of 10–50-μm diameter. Foams with Bioglass® inclusions showed similarly well-defined tubular and interconnected pore morphology. Cell culture studies using mouse fibroblasts (L929) were conducted to assess the biocompatibility of the scaffolds in vitro. L929 fibroblasts cultured in medium that was pre-conditioned by incubating with PLGA tubes containing Bioglass® had a significant reduction in cell proliferation compared with fibroblasts grown in unconditioned medium (p The PLGA and PLGA/Bioglass® tubular foams developed here are candidate materials for soft-tissue engineering scaffolds, holding promise for the regeneration of tissues requiring a tubular shape scaffold, such as intestine, trachea and blood vessels.
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pdlla Bioglass composites for soft tissue and hard tissue engineering an in vitro cell biology assessment
Biomaterials, 2004Co-Authors: Sophie Verrier, Veronique Maquet, Larry L. Hench, Jonny James Blaker, Aldo R BoccacciniAbstract:Abstract The aim of this study was to examine the effect of increased content of 45S5 Bioglass® (0–40 wt%) in poly( dl -lactic acid) (PDLLA) porous foams on the behaviour of MG-63 (human osteosarcoma cell line) and A549 cells (human lung carcinoma cell line). The ability of these cell lines to grow on bioactive composites was quantitatively investigated in order to assess the potentiality for their use in hard and soft-tissue engineering. Two hours after cell seeding, an increase of cell adhesion according to the increased content of Bioglass® present in the foams for both cell types was observed. Cell proliferation studies performed over a period of 4 weeks showed a better aptitude of the A549 cells to proliferate on PDLLA foams containing 5 wt% Bioglass® when compared to the proliferation on foams with 40 wt% Bioglass®. A lower proliferation rate was obtained for cells on pure PDLLA. Scanning electron microscopy analysis showed for both cell types the presence of cells inside the porous structure of the foams. These results confirmed the biocompatibility of PDLLA/Bioglass® composite foams and the positive effect of Bioglass® on MG-63 cell behaviour and also showed for the first time the possibility for human lung epithelial type II cells to adhere and proliferate on these porous scaffolds. In addition, we describe a positive effect of 45S5 Bioglass® on A549 cell behaviour in a dose-dependent manner, indicating the potential of using PDLLA/Bioglass® composites with an optimal concentration of 45S5 Bioglass® not only in bone tissue engineering but also in lung tissue engineering.
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preparation characterization and in vitro degradation of bioresorbable and bioactive composites based on Bioglass filled polylactide foams
Journal of Biomedical Materials Research Part A, 2003Co-Authors: Veronique Maquet, Ioan Notingher, Aldo R Boccaccini, L Pravata, Robert JeromeAbstract:Highly porous poly(D,L-lactide)/Bioglass® composites scaffolds were prepared by thermally induced phase separation process of polymer solutions and subsequent solvent sublimation. A series of composite foams with different polymer/Bioglass® weight ratios was prepared to study the influence of Bioglass® content on the foam characteristics such as porous structure, density, and pore volume. The pore volume was decreased from 9.5 to 5.7 cm3/g when the Bioglass® content was increased up to 40 wt %, but the overall pore morphology was not affected very much by changing the polymer/glass composition ratio. The composites foams were then incubated in phosphate-buffered saline at 37°C to study the in vitro degradation of the polymer and to detect hydroxyapatite (HA) formation as an indication of their bioactivity. The addition of Bioglass® to polymer foams increased the water absorption and weight loss as compared with pure polymer foams. However, the polymer molecular weight, determined by size exclusion chromatography, was found to decrease more rapidly and to a larger extent in absence of Bioglass®. This delayed degradation rate in the composite foams was probably caused by the dissolution of alkaline ions from the Bioglass®, resulting in a buffering effect of the incubation medium. After incubation for 7 days, HA was detected by X-ray diffractometry and Raman spectroscopy and confirmed by environmental scanning electron microscopy and energy-dispersive X-ray analysis. The porous composites developed here are promising materials for bone regeneration applications because the formation of HA on the surface of the pore walls should provide good environment for the adhesion and proliferation of osteoblasts and osteoprogenitor cells. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 335–346, 2003
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Bioresorbable and bioactive composite materials based on polylactide foams filled with and coated by Bioglass® particles for tissue engineering applications
Journal of Materials Science: Materials in Medicine, 2003Co-Authors: Aldo Roberto Boccaccini, Veronique Maquet, Ioan Notingher, R. JérômeAbstract:Poly(DL-lactide) (PDLLA) foams and bioactive glass (Bioglass) particles were used to form bioresorbable and bioactive composite scaffolds for applications in bone tissue engineering. A thermally induced phase separation process was applied to prepare highly porous PDLLA foams filled with 10 wt % Bioglass particles. Stable and homogeneous layers of Bioglass particles on the surface of the PDLLA/Bioglass composite foams as well as infiltration of Bioglass particles throughout the porous network were achieved using a slurry-dipping technique. The quality of the bioactive glass coatings was reproducible in terms of thickness and microstructure. In vitro studies in simulated body fluid (SBF) were performed to study the formation of hydroxyapatite (HA) on the surface of the PDLLA/Bioglass composites, as an indication of the bioactivity of the materials. Formation of the HA layer after immersion in SBF was confirmed by X-ray diffraction and Raman spectroscopy measurements. The rate of HA formation in Bioglass-coated samples was higher than that observed in non-coated samples. SEM analysis showed that the HA layer thickness rapidly increased with increasing time in SBF in the Bioglass-coated samples. The high bioactivity of the developed composites suggests that the materials are attractive for use as bioactive, resorbable scaffolds in bone tissue engineering.