重组合异种骨复合血管内皮生长因子基因转染骨髓间充质干细胞对非创伤性股骨头坏死的修复

Repairing effect of bone marrow mesenchymal stem cells transfected by vascular endothelial growth factor gene on non-traumatic osteonecrosis of the femoral head

目的:将复合有血管内皮生长因子基因转染的骨髓间充质干细胞的重组合异种骨植入病灶清除区,观察其修复股骨头坏死的效果。方法:体外分离、培养、鉴定骨髓间充质干细胞,PcDNA3/VEGF165质粒转染骨髓间充质干细胞,与重组合异种骨复合培养。应用局部液氮冷冻法造成的24只兔非创伤性股骨头坏死模型,左侧骨缺损处植入复合血管内皮生长因子基因转染骨髓间充质干细胞的重组合异种骨为治疗组,右侧仅植入单纯重组异种骨为对照组。行X射线,组织病理及股骨骨密度和矿物质含量检查。结果:①X射线片观察第6周时治疗组坏死区出现骨小梁结构,新骨形成增加,对照组仍呈现坏死区中心低密度,边缘高密度;第12周时治疗组股骨头形态规则,密度均匀,对照组股骨头坏死区有囊状低密度区。②第6周和12周时两组骨密度和矿物质含量差异有显著性意义(P<0.01)。③在组织学上,6周时治疗组骨细胞及微毛细血管明显多于对照组;12周治疗组新生骨组织修复达软骨下,对照组植入骨块仍有少量未吸收。结论:重组合异种骨复合血管内皮生长因子基因转染骨髓间充质干细胞具有明显的成骨诱导作用,能有效促进非创伤性股骨头坏死的早期修复。

OBJECTIVE： To observe the repairing effect of bone marrow mesenchymal stem cells （BMSCs） transfected by vascular endothelial growth factor （VEGF） gene on non-traumatic osteonecrosis of femoral head following implantation into the necrotic area. METHODS： BMSCs were in vitro isolated, culture, determined, and transfected with PcDNA3/VEGF165 plasmid; thereafter, the BMSCs were cultured with recombinant heterogenous bone. Femoral head necrosis in 24 rabbits was induced with liquid nitrogen. In the treatment group, rabbits were implanted with VEGF gene-transfected BMSCs on the left defected side; while in the control group, rabbits were implanted with BMSCs on the right defected side. X-ray examination, histopathological evaluation, femoral bone density analysis, and mineral matter content measurement were conducted. RESULTS： （1） X-ray examination indicated that bone trabecula structure and new bone formation were observed in the treatment group in defected area after 6 weeks; however, central density was low and marginal density was high in the control group. After 12 weeks, morphology of femoral head was regular and density was uniform in the treatment group, while a low-density band in capsular shape was observed in the control group. （2） There were significant difference in bone density and mineral matter content between the two groups at 6 and 12 weeks after implantation （P 〈 0.01）. （3） Numbers of osteocytes and blood capillary in the treatment were higher than control group after 6 weeks; in addition, after 12 weeks, nascent osseous tissue reached cartilage in the treatment group, and pieces of implanted bone remained in the control group. CONCLUSION： BMSCs transfected by VEGF gene have a strong activity of osteoinduction, so BMSCs implantation can effectively repair non-traumatic osteonecrosis of femoral head in an early stage.