复合血管内皮祖细胞的组织工程骨在修复大段骨缺损实验中的血管化评价

目的 评价复合了血管内皮祖细胞(EPCs)的组织工程骨在修复兔桡骨大段骨缺损实验中的血管化情况.方法 自体骨髓通过不同方法的体外培养,获得EPCs及经成骨诱导的骨髓基质干细胞(BMSCs),与脱钙骨基质(DBM)构建组织工程骨修复兔桡骨大段骨缺损.用墨汁灌注、放射性核素骨显像、血管内皮细胞生长因子和Ⅷ因子相关抗原的免疫组化方法观察术后不同时期实验组(EPCs+BMSCs+DBM)、自身对照组(BMSCs+DBM)、阴性对照组(DBM)的骨组织血管化情况.结果 各组手术后2周骨缺损区新生血管数量增加,血流量开始升高,4周和8周时达到峰值,12周后开始下降.实验绀的新生血管数量和局部血流量在术后2、4、8周明显高于自身对照组和阴性对照组,血管排列更整齐.结论 复合EPCs的组织工程骨在修复大段骨缺损时,能促进早期血管化,从而进一步促进成骨.

Vascularization of tissue engineered bone with endothelial progenitor cells in repairing large segmental defects

Objective To observe vascularization of tissue engineered bone compounded with endothelial progenitor cells (EPCs) in repairing large segmental defects of rabbit radius. Methods Bone marrow derived bone marrow mesenchymal stem cells (BMSCs) and EPCs of the same rabbit were cultured and harvested in vitro. The BMSCs and EPCs were seeded on decalcified bone matrix (DBM) to make tissue engineered bone which was later implanted into the large segmental bone defect of the radius in the donor rabbit. Vascularization of the tissue engineered bone was observed and evaluated by ink infusion, immunohistochemistry and radionuclide bone imaging in 3 groups: experimental group (EPCs+ BMSCs + DBM),own control group (BMSCs + DBM) and negative control group (DBM) . Results The number of new vessels and volume of blood flow in the bone defect area increased in the second post-operative week and reached the peak value in the forth and eighth post-operative weeks, while decreased in the twelfth. The number of new vessels and volume of blood flow in the experimental group were obviously higher than those in the own and negative control groups, and the former was better than the latter two in vessel alignment.Conclusion In repairing large segmental bone defects, tissue engineered bone combined with EPCs can promote early vascularization and thus improve the osteogenesis.