Papers by Keyword: Bioglass

Abstract: A glass (G) and a glass-ceramic (GC) of different composition were selected and studied to realize a biocompatible e/o bioactive material with antibacterial properties through the introduction of silver ions. The glass was produced in bulk form, instead glass-ceramic powders were sintered to abtain massive samples, which are characterized in terms of biocompatibility and subjected to ion- exchange technique [1] to allow the silver ions introduction and modify only the external surface layer of the materials, thus maintaining unchanged the bulk characteristics. The obtained samples were completely characterized to verify if the silver introduction leads to structural, morphological or in vitro behaviour change; silver release test was also carried out as well as antibacterial test with Staphylococcus Aureus and cytotoxicity test on human cells.

Abstract: The RF magnetron sputter technique was used to deposit Bioglass (BG) and hydroxyapatite (HA) coatings onto titanium substrates. The aim of this study was evaluated the growth behavior of rat bone marrow cells of various deposited coatings. The EDS measurements demonstrated that the composition BG coating was changed during magnetron sputtering. The rat bone marrow derived osteoblast-like cells showed improved osteogenic response on crystalline magnetron sputtered HA coatings compared BG coatings. Scanning electron microscopical examination showed an extensive mineralization after 16 days of culture, while on the surface of the BG coating only a multilayer without mineralization could be observed.

Abstract: Bioglass films were prepared by reactive magnetron sputtering from a 45S5 target and than annealed in air up to 550 oC in order to relax the mechanical stresses. The mixtures (0, 7 and 15%) of oxygen and argon were used in order to modify the films stoichiometry. Morphological and compositional studies were performed by SEM coupled with an EDAX system. FTIR and micro Raman measurements were performed in order to investigate the molecular vibrations of the BG structure. A modified composition respect to the target one was found for all the films, with lower silicon dioxide concentrations. The films displayed rough surfaces with spherical particles of 10-20 μm diameter embedded in the surfaces. The Raman results evidenced important carbonate lines besides the silica-phosphate bands.

Abstract: Various composition of calcium-silicate thinfilms were deposited to the thickness of 1μm by electron-beam deposition. The composition was varied by changing the composition of source. The Si concentration of thinfilm was ranged from 25 at% to 85 at%, evaluated by EDS. The specimens were immersed into PBS solution at 37 °C. Changes of the morphology and calcium phosphate formation on the specimens were examined by SEM. If the concentration of calcium is high, the calcium phosphate was quickly formed on the specimen. However, the calcium phosphate formed on the high calcium oxide concentration exhibited very poor adhesion onto the substrate. There is a range of appropriate calcium oxide concentration to use as a surface modification method for dental or orthopedic implants.

Abstract: Porous hydroxyapatite bioceramics were obtained by impregnating the polyurethane sponge with rheologically optimized slurry. 6wt% bioglass was doped into hydroxyapatite to act as a sintering additive. Thermal analysis was used to study the pyrolysis process of the polyurethane sponge. Phase component and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively. It was found that hydroxyapatite was the main phase composition of the porous ceramics sintered at 1250°C. The porous bodies prepared had an open, uniform and interconnected structure with pore size of 200-400μm. The porous ceramics possessed high porosity of 70-80% and compressive strength of 2.3MPa. The precipitates formed on the surface of the porous ceramics might be bone-like apatite after immersion in a simulated body fluid for various periods.

Abstract: Bioactive glasses are known to have the ability to regenerate bone, but their use has been restricted mainly to powder, granules, or small monoliths. This work reports on the development of bioactive glasses with macroporosity of controlled size and volume through sol-gel and pore forming technologies. The macroporous structure (greater than 100µm) can provide the potential for tissue ingrowth. Simultaneously the samples exhibit mesoporous (2-50nm) texture and high specific surface which can enhance bioactivity and release of ionic products. The most important advantage is that these samples show satisfactory mechanical strength. This method should be a useful approach for preparation scaffolds with applications to repair and reconstruct damaged tissue.

Abstract: In this paper, the hydration product of calcium phosphate cement with bioactive glass containing Si was used to investigate the effect of chemical composition on its bioactivity. The variation of concentrations of Ca2+, P and Si in TE solution complemented with electrolytes typical for plasma (TEE) and the formation of amorphous calcium phosphate layer on the surface of the materials were investigated by immersing the designed materials in TEE solution in vitro. The results showed that the composition of the bioactive composite CPC greatly affected its behavior in the solution and the formation of bioactive apatite. After immersed in TEE solution, the Ca ions were uptaken for all the samples, showing the decreases of Ca concentration during the entire duration, but the concentration of P ions increased sharply at the initial stage, and then decreased due to the formation of amorphous calcium phosphate layer on the surface of the materials. FTIR revealed that the layer was poorly crystallized Ca-deficient carbonate apatite. The thickness of the layer was more than 12 um, which layer was composed of rod-like apatite with directional arrangement. All the data obtained would be useful for the design and optimization of the orthopedic degradable implant inorganic materials.

Abstract: Preparation of bioactive glasses was attempted utilizing waste bovine as raw resource. Bioactive and biodegradable batch compositions in the Na2O-CaO-SiO2 system were included with calcined bovine, whose phase was high-purity oxy-hydroxyapatite. Bovine inclusion as large as 40 mass% was shown to present highly bioactive glasses; bovine in the bioactive and biodegradable compositions presented glasses with controlled bioactivity and biodegradability, respectively. These indicate not only a plenty biological resource of bio-interactive materials, but also an alternative strategy for bioactive glasses with multi-functional applications.

Abstract: Four rabbits received human derived HA to their left tibias. After 16 weeks bioglass was implanted to their right tibias. After other 16 weeks bone scintigraphies were taken with 99mTc- MDP. Three phase bone scan images showed no evidence of inflammation and superior vascularization rates at implantation sites. In this study, bioglass demonstrated higher uptake of 99mTc-MDP comparing to HA, suggesting a higher vascularization rate and better osseointegration.

Abstract: The porous poly（β-hydroxybutyrate-co-β-hydroxyvalerate）（PHBV）/bioactive glasses （BG） tissue engineering scaffold was prepared in this article. The mineralization behavior of the porous PHBV/BG scaffold was observed in simulated body fluid (SBF). The ion concentration of calcium, silicon and phosphorus in different mineralization periods were tested by inductively coupled plasma (ICP). The formation of the hydroxyl carbonate apatite(HCA) layer on the scaffold surface was confirmed by the Fourier transform infrared(FTIR) spectroscopy and X-ray diffraction(XRD) apparatus. The micro morphology and porosity of the scaffold before and after mineralization were observed by scanning electron microscopy(SEM). The in vivo biological evaluation of the porous PHBV/BG scaffolds was carried out by implanting the scaffold into the rat muscle to test the biocompatibility. The in vivo result shows that the composite exhibit good biocompatibility. The porous PHBV/BG scaffold is suitable for tissue engineering.