体外模拟和体内植入实验分析磷酸钙骨水泥的降解活性

目的 研究CPC及CPC／BMP复合人工骨降解性能，寻找加快CPC降解的有效途径，方法将CPC作为BMP的载体制成CPC／BMP复合物，在体外模拟生理环境进行CPC和CPC／BMP复合物的溶解试验。通过植入小鼠肌袋和犬桡骨植入试验，观察材料在体内的降解情况和降解规律。结果BMP促进了CPC的体外溶解。肌肉内植入CPC／BMP可以异位诱导新骨形成。植入骨缺损后CPC／BMP可以诱导新骨形成，有效地修复骨缺损。新骨形成的同时，材料出现了较快的降解。CPC不能异位诱导新骨形成，骨缺损修复能力较弱，降解缓慢。结论CPC／BMF，生物活性人工骨具有理想的降解性能和成骨能力，可望成为新型的骨缺损修复材料。

In vitro and in vivo study on the biodegradation of calcium phosphate cement after combined with bone morphogenetic protein

Objective To study the degradation rate of calcium phosphate cement(CPC) before and after combined with bone morphogenetic protein(BMP). Methods A new kind of non-ceramic hydroxyapatite cement of CPC was synthesized, and CPC/BMP composite was prepared to study its biodegrade rate through solubility test in vitro, inner-muscle implant test and inner-bone implant test. A series of examinations were carried out including radiography, histomorphology, scanning electron microscope(SEM), energy dispersion analysis X-ray(EDAX) and inorganic substance detection. Results Compared with CPC, the CPC/BMP composite had ideal solubility in phosphate buffer saline especially in flowing test. Total calcium released from the material in 14 days in flowing test was 16 times that in static test. When implanted the composite into muscle pouches of mice, new bone formation was observed with significant degradation of the material. No new bone formation and degradation was found in CPC group. Implant the CPC/BMP into 15mm-defect in the middle of the radial diaphysis of dogs, new bone had bridged the gap between the proximal and distal fragments by the end of 24 weeks, most of the CPC/BMP composite was degraded and absorbed. Only little new bone formed in CPC group and no visible degradation was found. Conclusion BMP was helpful in the degradation of CPC, and CPC/BMP composite has ideal degradation rate with great potential in bone defects repairing, so it could be used as material for bone graft substitute in clinical.