骨内应力环境下复合血管内皮生长因子骨髓基质干细胞修复创伤性股骨头坏死的实验研究

目的探讨骨内应力对转染VEGF基因的骨髓间充质干细胞修复创伤性股骨头坏死的作用。方法设计制作能骨内加压的空心螺钉,骨髓间充质干细胞培养并转染VEGF基因,20只实验犬通过手术截断股骨颈方法造模,根据术后不同的处理方法分为四组:A组(单纯空心螺钉固定);B组(空心螺钉加人工骨填塞);C组(空心螺钉加复合转染VEGF的骨髓间充质干细胞的人工骨填塞);D组(空心螺钉加复合转染VEGF的骨髓间充质干细胞的人工骨填塞,同时加压)。造模20周后,行大体观察、X线及组织学、免疫组化及Western blot检测骨修复效果。结果通过手术方式成功制作出创伤性股骨头坏死的动物模型;在造模20周后,D组血管计数和VEGF的蛋白含量明显高于其他三组(P<0.05);C组血管计数和VEGF的蛋白含量高于A组和B组,有显著性差异(P<0.05),低于D组比较有显著性差别(P<0.05);A组和B组血管计数和VEGF蛋白水平远低于C组和D组,差异有统计学意义(P<0.05)。A组和B组血管计数和VEGF蛋白水平之间的差异无统计学意义(P>0.05)。结论骨内加压能显著提高转染VEGF的骨髓间充质干细胞对创伤性股骨头坏死的再血管化,适当的应力刺激有利于骨组织的修复。

Vascular Endothelial Growth Factor Gene-modified Mesenchymal Stemcells for the Treatment of Traumatic Osteonecrosis of the Femoral Head in Internal Stress Environment of Bone

Objective To explore the effects of internal stress of bone on vascular endothelial growth factor gene-modified mesenchymal stem cells in repairing traumatic avascular necrosis of the femoral head in canine models.Methods Design and makethe hollow screws that can be intraosseous pressure,mesenchymal stem cell culture andVEGF-gene transfected.Animal model was set up by the femoral neck osteotomy.20 dogs were divided into 4 groups：Group A is the femoral neck fixating by hollow screw only;Group B is the femoral neck fixating by hollow screwand artificial bone;Group C is the femoral neck fixating by hollow screwand artificial bone composited VEGF transfected mesenchymal stem cells;Group D is the femoral neck fixating by hollow screwand artificial bone composited VEGF transfected mesenchymal stem cells,meanwhile, compressedscrew.After 20 weeks, repair effect of bone and blood vessel was determined by methods including Immunohistochemical technique, image analysis and Western blotting.Result The animal model of traumatic avascular necrosis of the femoral head was successfully produced through the operation.As shown in immunohistochemical techniqueand western blotting, Vessel count and VEGF-protein content, the Group D were significantly higher than the other three groups（P〈0.05）, the Group C were higher than the Group Aand the Group B（P〈0.05）but lower than the Group A.There was no significant difference between the group A and the group B（P〉0.05）. Conclusion Intraosseous pressure can significantly improve revascularization with the VEGF transfected mesenchymal stem cells on traumatic avascular necrosis of the femoral head.Appropriate stress stimulation to necrotic femoral head can speed up the repair of the bone.