RGD多肽表面修饰生物陶瓷修复骨缺损BMP-2的表达

目的：了解精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp,RGD）多肽表面修饰的羟基磷灰石-磷酸三钙（hydroxyapatite-tricalcium phosphate,HA-TCP）修复节段性骨缺损局部骨形态发生蛋白-2（bone morphogenetic protein-2,BMP-2）的表达。方法：以骨髓基质干细胞（marrow stromal cells,MSCs）复合RGD多肽表面修饰的HA-TCP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,实验根据植入不同的材料分为A、B、C和D组,A组：骨缺损区植入MSCs复合RGD多肽表面修饰的HA-TCP培养制备的组织工程骨;B组：骨缺损区植入MSCs复合HA-TCP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-TCP;D组：骨缺损区植入HA-TCP。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〈0.001,P〈0.05）。结论：RGD多肽表面修饰对以HA-TCP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 bioceramics modified superficially by RGD peptide

Objective To study the expression of BMP-2 on repairing segmental bone defect by HA-TCP modified superficially by RGD peptide. Methods MSCs were cocultured with HA-TCP modified by RGD peptide or simple material to produce tissue engineered bone. The experimental model of 15mm radial segmental defect was produced in 60 New Zealand white rabbits which were divided into A, B, C, D group according to different transplant materials. Group A: The bone defects were repaired by tissue engineered bone produced by MSCs cocultured with HA-TCP modified by RGD peptide. Group B: The bone defects were repaired by tissue engineered bone produced by MSCs cocultured with HA-TCP. Group C: The bone defects were repaired by HA-TCP modified by RGD peptide. Group D: The bone defects were repaired by HA-TCP. When the samples were harvested at 4 weeks postoperatively, the immunohistochemical detection of BMP-2 was carried out. Results All of the defects which had been 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: A >B > C > D (P<0.001, P<0.05) . Conclusion The surface modification of RGD peptide could optimize the repairing effect of tissue engineered bone produced by HA-TCP as scaffold material.