【摘要】 目的评价骨形态发生蛋白2(BMP-2)基因强化的组织工程骨联合显微外科方法修复长段骨缺损的效果。方法分离培养兔骨髓基质干细胞,经BMP-2基因转染后复合异种骨支架体外构建基因强化的组织工程骨(GEB)。建立兔双侧桡骨缺损(2.5 cm长)模型,采用5种方法修复。A:GEB加带血管蒂骨膜移植;B:GEB加血管束植入;C:GEB加游离骨膜移植;D:GEB;E:单纯支架。术后4、8、12周行X线、组织学、生物力学测定和微血管墨汁灌注等观察血管形成及成骨情况。结果A组血运建立最快,B组血管束早期即发出分支向移植骨内长入,C组4周时游离骨膜成活并发出微小血管,D组在BMP-2基因诱导下成骨速度和质量优于E组,12周时骨缺损部分修复,但中央区成骨不良,而E组12周时形成骨不连,缺损区内被纤维组织填充。在细胞成活率、生物力学性能、VEGF表达水平等方面,均表现为A>B>C>D>E,差异有统计学意义(P<0.05)。结论BMP-2基因强化的组织工程骨联合显微外科方法修复长段骨缺损,既提供了血运,又提供了有效的成骨诱导因子,是治疗长段骨缺损较为理想的方法。其中,带血管蒂骨膜联合移植修复效果最佳;血管束植入法血供重建较快,方便临床应用。更多还原

【Abstract】 Objective To evaluate the effects of repairing segmental bone defect by bone morphoge- netic protein 2 (BMP-2) gene enhanced tissue engineering bone with microsurgery methods.Methods Af- ter being transfected by adenovirus carrying BMP-2 gene,the rabbit bone marrow stromal stem cells were see- ded on bovine cancellous bone scaffolds to construct gene enhanced tissue engineering bone (GEB).The rab- bits radial defect (2.5 cm long) models were eonstructed bilaterally.Five methods were performed:GEB with vaseularized periosteum implantation (group A) ,GEB with vascular hundle implantation (group B) ,GEB with dissociated periosteum implantation (group C) ,GEB (group D) ,and only BCB scaffolds (group E).In 4,8, and 12 weeks after the operations,the X-ray,histological examination,biomechanical analysis and capillary ink infusion were administrated to observe angiopoiesis and osteogenesis.Results Group A appeared signifi- cantly better effect on the vascularization and osteogenesis than other groups.The vascular bundle in group B sent out new hranehes into the transplanted bones.In group C,the dissociated periosteum became productive in 4 weeks.The use of BMP-2 gene led to better osteogenesis in group D than in group E,but osteogenesis was slow in the central area of the defects which were healed partially in 12 weeks.Nonunion was present in Group E while the defect was filed up by fibrous tissue.When cell survival rate,biomechanical intensity and VGEF expression level were measured,A>B>C>D>E were all found in the above three aspects (P<0.05). Conclusion BMP-2 gene enhanced tissue engineering bone with microsurgery methods,which provided effec- tive osteoinduced factor as well as hlood supply,which is an ideal method for the treatment of segmental defect. Vascularized periosteum implantation method showed the best repairing effect.Vascular bundle implantation method reconstructed blood supply more slowly than the former method,but is convenient for clinical applioca- tion.更多还原