tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g...tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL -1 .The setting time could be adjusted,the maximum compressive strength was 45.36MPa,and the hydration product was hydroxyapatite (HAP).In vitro biological simulated experiments indicate that α TCP/TTCP bone cement has α certain dissolubility.The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks.The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response,no muscle stimulation,no haemolysis,no cruor,no inflammatory reaction and no exclusion response are caused by α TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging.α TCP/TTCP cement hydrated and hardened continually in vivo.The materials fused with host bone together with implanting time prolonging.Therefore,it is believed that α TCP/TTCP composite bone cement has a high biocompatibility and bioactivity,a certain biodegradation and good osteogenesis as well.展开更多
To improve the osteogenesis ability of a-tricalcium phosphate (α-TCP) bone cement, a novel BMP/ α-TCP composite bone cement was prepared. By measuring the setting time and compressive strength, the hydration charact...To improve the osteogenesis ability of a-tricalcium phosphate (α-TCP) bone cement, a novel BMP/ α-TCP composite bone cement was prepared. By measuring the setting time and compressive strength, the hydration characteristic of bone cement was evaluated. Animal experiments including histological observation, radiographic investigation as well as digital image analyses reveal the difference of osteogenesis ability among BMP,a-TCP bone cement and BMP/α-TCP composite bone cement. Results show that α-TCP bone cement possesses excellent hydration and setting properties as well as high mechanical property. Comparison experiments show that BMP/ α-TCP composite bone cement has a stronger osteogenesis ability. The gross observation of the implant site does not exhibit any inflammation or necrosis. Histological analyses reveal that the material has good osteointegration with host bone, and new bone formation is detected within the materials, which are degrading. Strong osteogenesis ability of the composite is due to not only the excellent osteoconductive potential but also the osteoinductive potential contributed by active BMP releasing and the material degradation. Large skull defect could be well-healed by filling BMP/α-TCP composite bone cement. This novel material proves itself to be an absorbable and bioactive bone cement with an osteogenesis ability. Key words α-tricalcium phosphate (α-TCP) - bone morphogenetic proteins (BMP) - bone cement - osteogenesis - osteoinductivity - bone tissue engineering Funded by 863 Hi-Tech Research and Development Program of China (2002AA326080) and the Fund for Outstanding Young Teacher of the Education Ministry of China(2002123)展开更多
The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentratio...The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentration of 0.05?mol/L or higher. The relationship between the setting time of the system cement and the concentration of citric acid solution shows concave type curve. When solution concentration was 0.2?mol/L, the setting time was 8 min, which was the shortest. While the relationship between 24?h compressive strength of the cement and the citric acid concentration shows convex type curve. When solution concentration was 0.2?mol/L, the compressive strength was 39.0?MPa, which was the highest. Afterwards, the microstructure of the hardening product was observed by SEM, the effect of citric acid on the exothermic rate of hydrate reaction was studied by microcalorimeter, and the crushed specimens were subjected to X ray diffraction. The results verified that the low citric acid concentration can accelerate the hydrate reaction rate of the α TCP/TTCP system. However, the high citric acid concentration inhibited hydroxyapatite formation and retarded the rate of hydrate reaction of the α TCP/TTCP cement.展开更多
文摘tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL -1 .The setting time could be adjusted,the maximum compressive strength was 45.36MPa,and the hydration product was hydroxyapatite (HAP).In vitro biological simulated experiments indicate that α TCP/TTCP bone cement has α certain dissolubility.The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks.The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response,no muscle stimulation,no haemolysis,no cruor,no inflammatory reaction and no exclusion response are caused by α TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging.α TCP/TTCP cement hydrated and hardened continually in vivo.The materials fused with host bone together with implanting time prolonging.Therefore,it is believed that α TCP/TTCP composite bone cement has a high biocompatibility and bioactivity,a certain biodegradation and good osteogenesis as well.
文摘To improve the osteogenesis ability of a-tricalcium phosphate (α-TCP) bone cement, a novel BMP/ α-TCP composite bone cement was prepared. By measuring the setting time and compressive strength, the hydration characteristic of bone cement was evaluated. Animal experiments including histological observation, radiographic investigation as well as digital image analyses reveal the difference of osteogenesis ability among BMP,a-TCP bone cement and BMP/α-TCP composite bone cement. Results show that α-TCP bone cement possesses excellent hydration and setting properties as well as high mechanical property. Comparison experiments show that BMP/ α-TCP composite bone cement has a stronger osteogenesis ability. The gross observation of the implant site does not exhibit any inflammation or necrosis. Histological analyses reveal that the material has good osteointegration with host bone, and new bone formation is detected within the materials, which are degrading. Strong osteogenesis ability of the composite is due to not only the excellent osteoconductive potential but also the osteoinductive potential contributed by active BMP releasing and the material degradation. Large skull defect could be well-healed by filling BMP/α-TCP composite bone cement. This novel material proves itself to be an absorbable and bioactive bone cement with an osteogenesis ability. Key words α-tricalcium phosphate (α-TCP) - bone morphogenetic proteins (BMP) - bone cement - osteogenesis - osteoinductivity - bone tissue engineering Funded by 863 Hi-Tech Research and Development Program of China (2002AA326080) and the Fund for Outstanding Young Teacher of the Education Ministry of China(2002123)
文摘The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentration of 0.05?mol/L or higher. The relationship between the setting time of the system cement and the concentration of citric acid solution shows concave type curve. When solution concentration was 0.2?mol/L, the setting time was 8 min, which was the shortest. While the relationship between 24?h compressive strength of the cement and the citric acid concentration shows convex type curve. When solution concentration was 0.2?mol/L, the compressive strength was 39.0?MPa, which was the highest. Afterwards, the microstructure of the hardening product was observed by SEM, the effect of citric acid on the exothermic rate of hydrate reaction was studied by microcalorimeter, and the crushed specimens were subjected to X ray diffraction. The results verified that the low citric acid concentration can accelerate the hydrate reaction rate of the α TCP/TTCP system. However, the high citric acid concentration inhibited hydroxyapatite formation and retarded the rate of hydrate reaction of the α TCP/TTCP cement.
文摘为提高α-磷酸三钙(-αTCP)骨水泥的强度及降低其脆性,将表面改性后的碳纤维(CF)与α-TCP粉复合,制备成-αTCP/CF复合增强骨水泥。通过R inger's体液浸泡观察骨水泥快速结晶自固化能力,运用扫描电子显微镜(SEM)及抗压强度测试仪对复合材料浸泡后试样进行断面显微结构分析及抗压强度测试。结果显示,α-TCP骨水泥块浸泡5 d后即转化生成片状羟基磷灰石晶体;适量的碳纤维在骨水泥基体中分布均匀,与基体结合性好,可得到抗压强度增强的骨修复材料;当碳纤维的加入重量百分数为0.5%时,复合材料抗压强度达到46.7 M Pa,比未增强的-αTCP材料提高了22%。
