羟基磷灰石晶体纤维增强磷酸钙骨水泥力学性能及生物相容性研究

目的将高长径比的羟基磷灰石(HA)晶体纤维添加入磷酸钙骨水泥(CPC)中,研究HA晶体纤维对CPC抗压力学性能增强的最佳配方及在体内的生物相容性。方法采用水热合成法制备高长径比HA晶体纤维,并验证其细胞毒安全性。将2.5%、5%及10%(wt%)HA晶体纤维添加入CPC中,分析并获取HA晶体纤维对CPC力学性能增强的最佳配方。使用最佳配方制备CPC+HA晶体纤维复合材料,植入大鼠胫骨近端骨缺损模型,4、8周组织学观察HA晶体纤维添加入CPC的成骨性能及生物相容性。对照组为单纯CPC实验组。结果成功制备高长径比HA晶体纤维,其细胞毒安全性为1级(RGR79%)。与对照组相比,2.5%及5%HA晶体纤维添加入CPC可以增强材料的抗压力学性能(P<0.05),其中5%HA晶体纤维对CPC抗压性能的增强效果最佳,10%HA晶体纤维略降低CPC的抗压性能,但无统计学差异(P>0.05)。大鼠体内研究结果显示:与对照组相比,5%HA晶体纤维添加入CPC复合材料植入后材料周围骨体积分数(BV/TV)无显著性差异(P>0.05),HA晶体纤维添加入CPC后材料周围成骨与材料接触好,生物相容性良好。结论水热合成法制备的HA晶体纤维作为添加剂,具有增强CPC抗压力学性能,减低CPC脆性,生物相容性良好的特点,可用作骨植入生物材料的添加剂。

Compressive strength reinforce and biocompatibility of the hydroxyapatite whisker added into calcium phosphate cement

Objective To manufacture the composite by incorporating hydroxyapatite(HA) whisker with a high-aspect-ratio into calcium phosphate cement(CPC),and evaluate the mechanical property and biocompatibility of the composite.Methods HA whisker was successfully synthetized via hydrothermal synthesis and its cytotoxicity was investigated through the MTT assays.Different content of 0 %,2.5 %,5 %,10 %(wt%) HA whiskers was incorporated into CPC.The compressive strength of the samples was measured using a mechanical testing machine to get the best formula of the composite.The composites were implanted into tibia bone defect of the Sprague-Dawley(SD) rat model and its biocompatibility was evaluated on 4,8 weeks postoperatively.Results HA whisker was successfully synthesized and its cytotoxicity was observed at stage one(RGR 79%).The compressive strength of composites of 2.5%,5%(wt%) HA whisker incorporated into CPC was significantly higher than CPC(control group)(P<0.05).The composite of 5%(wt%) HA whisker incorporated into CPC was the best formula.The compressive strength was decreased when 10% HA whisker were added into CPC but no statistically significant was proved(P>0.05).In vivo studies suggest that the biocompatibility of composite was satisfied when they were implanted into the tibia bone defect of SD rats.When the composite of 5%(wt%) HA whisker incorporated into CPC,the bone volume fraction(BV/TV) was no significant difference between two groups(CPC as control group)(P>0.05).Conclusions HA whisker can increase the compressive strength and decrease the friability of CPC.The satisfied biocompatibility of HA whisker may provide it possible potential usage as an additive in biomaterials.