hBMP-2基因修饰的组织工程化骨修复兔桡骨节段性缺损

hBMP-2 gene modified tissue engineered bone repair the segmental bone defect of rabbit＇s radius

目的利用免桡骨节段性骨缺损模型，比较评估hBMP-2基因修饰的组织工程化骨修复骨缺损的能力。方法利用腺病毒载体Adeno-X^TM将hBMP-2基因转染新西兰大白兔骨髓间充质干细胞（BMSCs），培养扩增3周后接种于磷酸钙／纤维蛋白胶复合支架材料，构建成基因修饰的组织工程化骨（A组）；将自体BMSCs培养扩增3周后接种于磷酸钙／纤维蛋白胶复合支架材料（B组）和单纯磷酸钙／纤维蛋白胶复合支架材料（c组）作为对照组，与A组同时回植于供体兔桡骨节段性骨缺损。另外骨缺损模型自行修复组（D组），作为空白对照。分别于术后4周、8周、12周行大体观察，X线摄影，99^m Tc-MDP SPECT和组织学检查并比较其骨愈合率。结果实验组（A、B、C组）骨缺损部位均有新骨生成，12周时，均能达到骨性愈合，而空白对照（D组）仍为纤维组织充填；A组成骨数量，成骨速度和骨愈合率均高于B、c组，而B、C组之间差异无统计学意义。结论hBMP-2基因修饰的组织工程化骨成骨能力强，骨愈合率高，是一种理想的骨移植材料。

Objective To compare and evaluate the defect-repaired capabilities of human bone morphogenetic protein-2 （hBMP-2） gene modified tissue engineered bone in the segmental bone defect model of rabbit＇s radius. Methods Rabbit＇s bone mesenchymal stem cells （BMSCs） were transferred with hBMP-2 gene through Adeno-XTM adenoviral expression systems, then seeded onto the compound scaffold of calcium phosphate cement （CPC） and fibrin glue （FG） to construct a new kind of gene modified tissue engineered bone after proliferation in vitro for three weeks （ Group A）. Meanwhile, the compound scaffold of calcium phosphate cement （CPC） and fibrin glue （FG） , which were seeded by rabbitg bone mesenchymal stem cells （BMSCs） after proliferation in vitro for three weeks （group B ） and the compound scaffold without cells （Group C） acted as control groups. Then, three kinds of reconstructive modalities were implanted into segmental bone defect of donator rabbit;s radius. Besides these three groups, bone defect model of rabbit＇s radius without treatment （ Group D） represented blank group. The defect -repaired capabilities were assessed by gross observation, radiograph, Single Photo Emission Computed Topography （SPECT） and histological analysis in the 4th week, 8th week and 12th week after operation. The rates of bone healing in the different groups were compared each other. Results All defects that had been treated with implants （Group A, B, C） exhibited new bone formation and could attain osseous tissue healing 12 weeks after operation, but defects in blank group （Group D） were repaired only by fibrous tissue. The defects in the Group A regenerated more new bone, bridged earlier and stronger than those in the Group B and Group C. The quantity and rate of new bone formation in the Group B and Group C had no significant difference and the rates of bone healing in different groups showed the same results. Conclusion hBMP-2 gene modified tissue engineered bone have better potential to form new bone and the rate of bone healing in repairing bone defects is higher, so this way is an optimal kind of material for artificial bone graft.