纳米双相陶瓷人工骨的成骨及降解

背景：烧结后的纳米羟基磷灰石结晶度很高,在体内很难降解;纳米β-磷酸三钙的降解速度太快,不利于体内生物组织在材料上附着,不利于引导成骨.目的：观察纳米羟基磷灰石/纳米β-磷酸三钙双相陶瓷人工骨的成骨及降解性能.方法：将36只青紫蓝兔随机分为实验组、对照组及空白组,制作左侧挠骨缺损模型,实验组与对照组分别植入纳米羟基磷灰石/纳米β-磷酸三钙双相陶瓷人工骨、纳米羟基磷灰石人工骨,空白组不植入任何材料.术后4,8,12周观察成骨和材料降解情况.结果与结论：①术后12周时 X 射线：实验组可见材料基本降解,连续性骨痂通过骨缺损部位.对照组材料未见明显降解,骨缺损处有骨痂修复.空白组骨缺损未见修复.②术后12周时组织学观察：实验组材料孔隙内以骨细胞和成骨细胞为主,有少量软骨细胞,出现散乱的骨松质,材料完全降解.对照组材料孔隙内以骨细胞为主,有少量成骨细胞和软骨细胞,材料未见明显降解.空白组可见纤维结缔组织及胶原纤维.③术后12周时扫描电镜观察：实验组材料降解,骨缺损部位被新生骨松质取代.对照组材料未见降解,骨缺损部位大都被新生骨松质取代.空白组无明显骨重建.表明纳米羟基磷灰石/纳米β-磷酸三钙双相陶瓷人工骨具有良好成骨能力及降解性能.

Osteogenesis and degradation performances of nano biphasic ceramic artificiai bone

BACKGROUND： Nano-hydroxyapatite has a high crystal inity after sintering and difficultly degrades in vivo. Due to the high degradation rate, nano-β-tricalcium phosphate is not conducive for the biological tissue to attach on the material in vivo, which is not conducive to osteogenic induction. OBJECTIVE： To observe the bone formation and degradation performances of nano-hydroxyapatite/ nano-β-tricalcium phosphate biphasic ceramic artificial bone. METHODS： Thirty-six Chinchil a rabbits were randomly divided into experimental group, control group and blank group, and the rabbits were used to establish the left radius bone defect model. The rabbits in the experimental group and the control group were implanted with nano-hydroxyapatite/nano-β-tricalcium phosphate biphasic ceramic artificial bone and nano-hydroxyapatite artificial bone respectively, and the blank group was not implanted with any materials. The bone formation and degradation performances were observed at 4, 8 and 12 weeks after implantation. RESULTS AND CONCLUSION： X-ray film at 12 weeks after operation showed that the materials in the experimental group were basical y degraded, the continuity cal us grew through the bone defect site; the materials in the control group were not degraded obviously, and there was cal us at the bone defect site; the bone defect in the blank group was not repaired. Histological observation at 12 weeks after operation showed that the material pores in the experimental group were fil ed with bone cells and osteoblasts, as wel as a smal amount of chondrocytes, the scattered cancel ous bone appeared and the materials were completely degraded; the material pores in the control group were fil ed with bone cells, as wel as a smal amount of osteoblasts and chondrocytes, and the materials were not degraded completely; fibrous connective tissue and col agen fibers could be seen in the blank group. Scanning electron microscope observation at 12 weeks after operation showed that in the experimental group, the materials were degraded, and the bone defect sites were replaced with new bone cancel ous bone; materials in the control group were not degraded, and most of the bone defect sites were replaced with new cancel ous bone; no obvious bone reconstruction could be seen in the blank group. The results indicate that nano-hydroxyapatite/nano-β-tricalcium phosphate biphasic ceramic artificial bone has good degradation performances.