缓释微囊化杜仲提取物复合钙磷骨水泥修复兔骨缺损

Repair of rabbit femoral condyle defect by microcapsules of Eucommia extracts combined with calcium phosphate cement

目的 探讨磷酸钙骨水泥（CPC）/杜仲微囊复合材料修复骨缺损的效果和最佳比例.方法 在新西兰兔双侧股骨髁部形成洞型骨缺损,实验侧骨缺损分为A、B组,分别置入含0.304、0.608mg/ml微囊杜仲提取物的CPC复合材料,对照侧置入CPC为C组,空白侧不填充为D组.在术后2、4、8、12周时取出股骨,进行大体观察、X线摄片、病理学观察及骨形成蛋白-2（BMP-2）和血管内皮生长因子（VEGF）免疫组化染色.结果 X线摄片提示术后12周B组植入材料无残留,A组有少量材料存留,C组材料明显存在.病理学观察术后4周B组骨水泥材料中成骨细胞生长活跃,A、C组仅在宿主骨表面有成骨细胞和新生血管 12周时A、B组髓腔贯通,C组髓腔未贯通,同时B组材料完全降解,A、C组材料未完全降解.统计学分析术后4周BMP-2因子实验组明显高于对照组,差异有统计学意义（P＜0.05）.结论 杜仲提取物给微囊包裹,以0.608mg/ml比例与CPC复合修复兔股骨髁缺损使杜仲有效成分缓释,诱导新骨形成作用强、降解时间快、优于CPC且比例较适宜.

Objective To evaluate the application of microcapsules Eucommia extracts （ME） and calcium phosphate cement （CPC） compositions （ME/CPC） in repairing bone defects in rabbits. Methods circular bone defects with 6mm in diameter were induced in both femoral condyle of rabbits, ME/CPC compositions （ME and） were implanted into the experimental sides, group A： CPC ＋ ME （0.304mg/ml）, group B： CPC ＋ ME （0.608mg/ml）, CPC alone was used in the control side （group C）. Gross appearance, X-ray, histological, and immunohistochemical studies were performed, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） were measured at 2, 4, 8, 12 weeks after treatment. Results X- ray showed that cortical bone of group B was healed with marrow cavity through, almost no residual material; that in group A had small retention, while in group C considerable amount of repairing material left. Histological examination showed that a large number of spindle cell infiltrated into bone cement after 4 weeks in group B, groups A and C had osteoblasts and angiogenesis in the host bone surface, in group C trabecular bone was thinner. The medullary cavity was formed in group A and B at 12th week, but not in group C. Repairing materials in group B completely degraded, while in group A and C only partial was degraded. BMP-2 levels in group A and B at week 4 were significantly higher （P〈0.05） than those in group C. Conclusion The microencapsules containing 0.608mg/ml Eucommia extracts with CPC enhances new bone formation and fast degradation in repair of rabbit femoral condyle defect.