新型组织工程化骨磷酸钙骨水泥/聚乳酸-聚羟基乙酸复合骨髓间充质干细胞修复兔桡骨缺损**☆

背景：前期已成功制备磷酸钙骨水泥/聚乳酸-聚羟基乙酸（calcium phosphate cements /PLGA, CPC/PLGA）生物复合材料，并证实其具有良好的机械强度和生物相容性。 目的：进一步验证CPC/PLGA复合骨髓间充质干细胞作为一种新型组织工程化骨材料修复骨缺损的可行性。 设计、时间及地点：随机对照动物体内观察，于2004-01/2005-12在中南大学湘雅三医院中心实验室完成。 材料：自制CPC/PLGA支架材料，与兔骨髓间充质干细胞复合培养制备组织工程骨。 方法：日本大耳白兔40只，制备桡骨骨缺损模型后随机分成4组，于骨缺损处分别植入组织工程骨、CPC/PLGA复合材料、复合了种子细胞的磷酸钙骨水泥及单纯磷酸钙骨水泥。 主要观察指标：经不同时间的X射线片、组织形态学及电镜观察，了解各组材料的成骨作用。 结果：X射线照片显示组织工程骨组不同时间新骨形成的量均优于其他组，其骨缺损修复的方式和速度均优于其他组；组织学观察到组织工程骨组的成骨细胞及骨小梁出现均早于其他组；电镜结果表明，与其他组相比较，组织工程骨组的成骨速度较快。 结论：种植了骨髓基质干细胞的CPC/PLGA复合物能促进骨组织生长，有望作为一种新型人工骨材料修复骨缺损。

Repair of radial defects using calcium phosphate cements/poly lactic-co-glycolic acid materials combined with mesenchymal stem cells in rabbits

BACKGROUND: It is confirmed that calcium phosphate cements/poly lactic-co-glycolic acid (CPC/PLGA) composites materials which were successfully prepared has good mechanical strength and biocompatibility. OBJECTIVE: To further verificate the feasibility of the composite CPC/PLGA materials combined with mesenchymal stem cells to repair segmental bone defects. DESIGN, TIME AND SETTING: The randomized control experiment of in vivo observation was perfomed at the Central Laboratory of the Third Affiliated Hospital of Xiangya Medical College, Central South University from January 2004 to December 2005. MATERIALS: Preparated tissue engineered bone with self-made CPC/PLGA materials combined with rabbit mesenchymal stem cells. METHODS: Forty Japanese white rabbits were randomly divided into 4 groups after created radius bone defects models. Tissue engineered bone, CPC/PLGA materials, CPC/PLGA materials combined with mesenchymal stem cells and CPC were implanted into bone defects, respectively. MAIN OUTCOME MEASURES: The osteogenic effects of materials were investigated by X-ray examination, histomorphology and electron microscope observation at different times. RESULTS: X-ray results showed that the amount of new bone formation in the tissue engineered bone group was more than that in the other groups at different times, the degradation rate was also faster. Osteoblasts and bone trabecula in the tissue engineered bone group appeared earlier than other groups. Electron microscope photograph showed that bone formation rate in the tissue engineered bone group was faster than that of the other groups. CONCLUSION: The CPC/PLGA materials combined with mesenchymal stem cells could promote the growing of bone issues, it is a kind of new bio-composite material for repairing bone defects.