基因重组人骨形成蛋白-2与珊瑚/聚乳酸复合修复骨质缺损的实验研究

目的　观察生物珊瑚、聚乳酸和rhBMP-2合成人工骨(复合骨)修复兔颅骨缺损后复合骨的变化情况。方法　选择24只新西兰兔,随机分成2组,每组12只,建立兔颅骨缺损标准模型。植入复合骨,用珊瑚/聚乳酸作为对照。术后4、8、12周每组各处死4只动物,取出植入体进行扫描电镜观察和机械强度测定。结果　复合骨在植入缺损后,不仅在植入体周边部有骨组织长入,而且在整个植入体内均有新骨形成,即出现多中心成骨。复合骨在同一时间点的成骨量明显多于对照组,随时间推移,成骨量递增。在植入前,两材料间的抗压强度无明显差异;在植入后,两植入体的抗压强度则差异显著,复合骨明显高于同期的对照组。结论　生物珊瑚、聚乳酸和rhBMP-2合成人工骨在体内以传导成骨和诱导成骨双重机制完成骨修复,且有良好的机械强度,作为植骨材料具有良好的应用前景。

Experimental Study of Artificial Bone Composite of Bicoral, rhBMP -2 and PLA in Repairing Calvarial Defects

Objective To study the effects of artificial bone composite of bicoral,rhBMP-2 and PLA in repairing calvarial critical-size defects.Methods Calvarial defects in 24 rabbits were surgically made and then half of the defects were repaired with the artificial composite bone. Another half of them were repaired with bicoral / PLA composite and served as controls. Four rabbits in each group were sacrificed at 4,8,12 weeks after operation, respectively. The treatment effects were evaluated with scanning electron microscopy and mechanical strength testing.Results New bone was observed not only in the periphery, but also inside the artificial bone in both groups, but earlier and more new bone formation was observed in treatment group compared with control group. The mechanical strength test showed that the artificial bone in two groups, which had same mechanical strength before implantation, had significant different mechanical strength after operation. The strength of the artificial composite bone was higher than that of controls and was same with normal rabbit calvarial bone.Conclusion The artificial composite bone possess a highly repairing ability, and the healing in bone defects may be accomplished by both osteoinductive and osteoconductive mechanism. The material may be used as a good substitute for bone grafting.