脱蛋白骨联合VEGF基因转染治疗股骨头缺血坏死

目的探索一种新的方法治疗股骨头早期缺血性坏死（avascular necrosis of the femoral head，AVNFH）。方法69只AVNFH造模成功后的新西兰大白兔随机分成3组。第1组，将脱蛋白骨（deproteinized bone，DPB）复合pcDNA3．1／VEGF165质粒植入坏死的股骨头内，第2组植入DPB，第3组仅在股骨头内钻一隧道。术后3d，1、2、4、8和16周获取标本。RT—PCR、Western blot和免疫组化技术分别检测VEGF165 mRNA、蛋白的表达及安全性。X线大体观察成骨情况，组织形态学分析血管发生和股骨头修复。结果第1组VEGF165 mRNA和蛋白表达术后1周达到高峰，时间持续超过3周，第1组动物术后远膈脏器未检测到VEGF165的表达。血管形成术后2，4周增加，骨形成术后2，4和8周增加，与另两组相比差异有显著性（P〈0．01）。结论VEGF165基因转染可促进局部血管的早期形成，DPB-VEGF复合物可增加骨形成，VEGF基因治疗兔AVNFH有效、安全，脱蛋白骨联合VEGF165基因治疗为骨坏死的修复提供了理论基础。

Deproteinized bone with VEGF gene transfer for avascular necrosis of the femoral head

Objective To explore a new method for early avascular necrosis of the femoral head(AVNFH) therapy.Methods Sixty-nine New Zealand adult rabbits with a mean weight of 2.8 kg after AVNFH establishment were randomly divided into 3 groups.In group 1,the deproteinized bone(DPB) combined with the recombinant plasmid pcDNA3.1/VEGF165 was implanted in the drilled channel of the necrotic femoral head.In group 2,only DPB was implanted.In group 3,only channel was drilled without DPB or plasmid implantation.Femoral head specimens were obtained at 3 d,1,2,4 and 8 weeks after operation. The expression of vascular endothelial growth factor(VEGF) and the security of this manipulation were examined by RT-PCR,Western blotting and immunohistochemical techniques.X-ray examined bone formation generally.Angiogenesis and repair of the femoral head were observed by histological and histomorphometric analysis.Results In group 1,the expression of VEGF was detected in the femoral head implanted by DPB-VEGF compound.The expression of VEGF165 mRNA and protein reached the maximum in 1 week after implantation and lasted more than 3 weeks,but none of them were detected in distant organs.The femoral head implanted by DPB-VEGF compound showed a significant difference in vascularization at 2 and 4 weeks and a significant difference in bone formation at 2,4 and 8 weeks after operation from those in other groups on histomorphometric analysis(P<0.01).Conclusion The transfection of the VEGF165 gene enhances local angiogenesis in early stage and DPB-VEGF compound improves bone formation.VEGF gene therapy on rabbit AVNFH is effective and secure.The deproteinized bone combined with VEGF gene provides a potential method for therapy of osteonecrosis.