表面修饰羟基磷灰石修复骨缺损骨形态发生蛋白-2的表达

目的了解精氨酸-甘氨酸-天冬氨酸多肽表面修饰的羟基磷灰石（hydroxyapatite,HA）修复节段性骨缺损局部骨形态发生蛋白-2（bone morphogenefic protein-2，BMP-）的表达。方法以骨髓基质干细胞（marrow stromal cels，MSCs）复合Arg-Gly-Asp（RGD）多肽表面修饰的HA或单纯材料培养制备组织工程骨，选择60只新西兰白兔。制作15mm长的桡骨节段性骨缺损模型，根据植入不同的材料分为A、B、C、D组。A组：骨缺损区植入MSCs复合RGD多肽表面修饰的HA培养制备的组织工程骨；B组：骨缺损区植入MSCs复合HA培养制备的组织工程骨；C组：骨缺损区植入RGD多肽表面修饰的HA；D组：骨缺损区植入HA。术后4周取材，行修复区局部BMP-2免疫组化分析。结果术后4周各组骨缺损区均有新骨生成，修复区局部BMP-2表达水平依次为：A〉B〉C〉D（P〈0．05）。结论RGD多肽表面修饰对以HA为支架材料组织工程骨的修复作用有明显优化作用。

The expression of BMP-2 on repairing bone defect by surface modified HA

Objective To study the expression of bone morphogenetic protein-2 （BMP-2） on repairing segmental bone defect by surface modified hydroxyapatite （HA） with Arg-Gly-Asp （RGD） poly peptide. Methods Marrow stromal cells （MSCs） were coeuhured with HA modified by RGD peptide or simple material to produce tissue engineering bone. The experimental model of 15 mm radial segment defect was established in 60 New Zealand white rabbits and divided into A,B,C,D group （10 in each group ） according to different transplant materials. Group A ：The bone defects were repaired by tissue engineering bone produced by MSCs coeultured with HA modified by RGD peptide. Group B：The bone defects were repaired by tissue engineering bone produced by MSCs cocuhured with HA. Group C ：The bone defects were repaired by HA modified by RGD peptide. Group D ：The bone defects were repaired by HA. When the samples were harvested at 4 weeks postoperatively,the immunohistoehemical detection of BMP-2 was performed. Results All of the bone defects treated with implants exhibited new bone formation at 4 weeks postoperatively. The expression of BMP-2 on repairing segmental bone defect was ranged as follows ： group A 〉 B 〉 C 〉 D （P 〈 0.05 ）. Conclusion The surface modification of RGD peptide could optimize the repairing effect on tissue engineering bone produced by HA as scaffold material.