Papers by Keyword: Tri-Calcium Phosphate

Abstract: Calcium phosphate ceramic scaffolds have been widely investigated for bone tissue engineering due to their excellent biocompatibility and biodegradation. Unfortunately, they have low mechanical properties, which inversely restrict their wide applications in load-bearing bone tissue engineering. In this study, porous Si-doped tri-calcium phosphate (TCP) ceramics with a high porosity (~65%) and with interconnected macrotubes (~0.8mm in diameter) and micropores (5-100 μm) were prepared by firing hydroxyapatite (HA)/ bioactive glass-impregnated acrylontrile butadiene styrene (ABS) templates at 1400 °C. Results indicated that the cylindrical scaffolds had a higher compressive strength than the cubic scaffolds and the smallest cylindrical scaffold had a highest compressive strength (14.68+0.2MPa). Additional studies of cell attachment and MTT cytotoxicity assay proved the bioactivity and biocompatibility of the Si-doped TCP scaffolds.

Abstract: Calcium sulfate/tri-calcium phosphate (CaSO₄/TCP) composite bone fillers were fabricated through molding method. Their structure and properties were characterized by infrared spectroscope, scanning electronic spectroscope, x-ray diffraction and degradation test. The results show that TCP crystals were attached to the CaSO₄ crystals and prevented the growing of sulfate crystals. So their size is shorter than that of CaSO₄ crystals prepared from pure CaSO₄ semihydrate, and some even had defect. The resorption rate of CaSO₄ bone fillers was decreased when TCP was incorporated.

Abstract: It has been reported in the biocompatibility researches performed in-vivo and in-vitro that the electric signals produced by piezoelectric implants may induce accelerated healing of the injured tissue after implantation. Barium titanate (BaTiO3; BTO), as a well known piezoelectric ceramic, is a suitable candidate to be used in these kind of biomedical researches about the effect of the electrical polarity and piezoelectricity on tissues. The excellent biocompatibility and faster bone adaptation characteristics of hydroxylapatite (HA) have been well documented in the literature. Therefore, HA / BTO composites may be a suitable bioceramic material introducing both the piezo effect and biocompatibility at the same time. However, the main point to process such composites should be to keep HA and BTO phases as stable as possible not to loose the biocompatibility of HA and the piezoelectricity of BTO ceramics. In this research HA / BTO, piezo-composites were prepared with powder mixing method in various mixing ratios and sintered at the temperatures between 500 and 1300 oC. Sintering was carried out under different atmospheres to evaluate the effect of atmosphere on the phase stability of composites. Then composites are characterized with XRD, DTA, density measurements and d33 piezoelectricty coefficient measurements.