优化配方的CPC/DBM/rhBMP-2复合材料在体内的超微结构和组织学特征

Ultra microstructure and histological properties in vivo of excellent composition of decalcified bone matrix impregnated calcium phosphate cement with recombinant human bone morphogenetic protein-2 in periods

目的探讨磷酸钙骨水泥(CPC)/脱钙骨基质颗粒(DBM)/重组人骨形成蛋白-2(rhBMP-2)复合材料在骨内的超微结构和组织学特征,评价该材料的成骨性能。方法预制兔DBM,按0.2的DBM质量比制作CPC/DBM/rhBMP-2复合材料。将复合材料(A组,n=12)、CPC(B组,n=10)、医用骨水泥(C组,n=7)分别植入兔股骨髁部骨缺损,在植入后第6、12、24周取材进行组织学和扫描电镜观察。结果术后第6周,A组中复合材料-骨界面模糊,宿骨发出纤维连续通过界面,编织骨样结构开始向材料内部长入。第12周,A组中血管和成骨细胞在复合材料内部生长,产生新骨。第24周,A组中骨缺损已修复,形成骨性连接,材料大部分被新骨替代。B组术后第6周CPC-骨界限清晰,未见新骨向材料内部长入,第24周骨缺损部位仍为CPC填充,材料内部未见新骨出现。C组材料直至第24周尚未与宿骨形成任何连接。A组材料在成骨细胞活性、血管化程度和新骨生长速度方面均优于B组。结论将DBM质量比为0.2的复合材料植入骨缺损内可以促进细胞、血管、新骨的长入,且易降解及被自体骨替代。

Objective To analyze the ultra microstructure and histological properties of implanted composites of decalcified bone matrix （DBM） impregnated calcium phosphate cement （CPC） with recombinant human bone morphogenetic protein-2 （rhBMP 2） in bone defect, and evaluate the osteoplastic efficiency of this composites. Methods The rabbit DBM was prepared beforehand. The composites of DBM impregnated CPC with rhBMP 2 was made at 0. 2 proportion of DBM. The rabbit＇s bone defect of femur condyle was filled with implantation of the composites （group A, n=12） or CPC （group B, n=12） or bone cement （group C, n=12）. Animals were sacrificed at 6, 12, or 24 weeks after operation, and the implants were examined by histological technique and scanning electron microscopy （SEM）. Results In group A, at the 6th week after operation, the interface region between implants and bone tissue became fuzziness, and was crossed by the generated fibers of bone tissue, and filled with woven bone growing inside into the composites; at the 12th week after operation, blood vessels, osteoblasts and new bone were generated inside of composites; at the 24th week after operation, the bone defects were recovered and became solid union, most of the implants were replaced by new bones. In group B, at the 6th week after operation, the interface of CPC and bone tissue was sharp, and was not crossed by new bones; at the 24th week after operation, the bone defects were still filled with materials of CPC and no new bone was found inside CPC. In group C, at the 24th week after operation, the interface of bone cement and bone remained nonunion. Higher osteoblastic activity,more neogenetic blood vessels and higher growth rate of woven bone were observed in group A compared with those in group B. Conclusions For bone defect, the implantation of composites with DBM proportion of 0.2 can stimulate the growth of osteoblast, blood vessel and woven bone. It is biodegradable and can be replaced by autogenous bone.