检测rhBMP-2/明胶复合材料的诱导成骨活性:修复兔长骨缺损的实验研究

An investigation of the composite of rhBMP-2 and gelatin in repairing the segmental defect of rabbit's long bone

目的观察rhBMP-2/明胶复合材料修复兔长骨节段性骨缺损的能力。方法手术造成桡骨中上段15mm骨缺损,实验组植入rhBMP-2/明胶复合材料片,其中rhBMP-2的含量为1.0mg,对照组植入单纯明胶片。通过影像学、组织学观察及骨密度测定。结果影像学检查示实验组术后4周时缺损区有大量新生骨痂形成,术后8周时新生骨痂将缺损区桥接,术后12周时达到皮质骨连接;对照组无骨痂形成。组织学检查示实验组术后4周时的骨痂为编织骨,术后8周时骨痂外层为板层骨,中央为编织骨,内有骨髓组织,术后12周时骨痂外层为皮质骨,中央为髓腔组织;对照组缺损区为结缔组织和肌组织充填。骨密度测定示术后12周时骨痂密度达到正常值的76%。结论rhBMP-2/明胶复合材料具有良好的诱导成骨活性,1.0mg的rhBMP-2能够很好的修复兔桡骨15mm的骨缺损。

Objective To survey the effect of the composite of rhBMP-2 and gelatin in repairing the segmental defect of rabbit's long bone, and to examine the activity of rhBMP-2. Method A 15 mm defect was made in middle-superior segment of rabbit's radius, then in experiment group the composite of rhBMP-2 and gelatin was implanted into the defect, in which the content of rhBMP-2 was 1.0 mg; in control group only gelatin was implanted. The repairing effect was evaluated in 4, 8, 12 weeks of postoperation by radiograph, histology and BMD (bone mineral density). Result Radiographically, the new callus can be seen in defect sites by 4 weeks of postoperation; all defect sites were bridged by callus by 8 weeks and connected by cortical bone by 12 weeks in experiment group. But in control group, no callus was seen. Histologically, the new callus formed in 4 weeks was woven bone; by 8 weeks, defect sites in experiment group were bridged with lamellar bony callus, in witch there was myeloid tissue.; by 12 weeks, in the outside of callus the compact bone was formed, and in the centre the medullary cavity was seen. In control group, defect sites were filled by connective tissue and muscle tissue. The BMD of the new callus was about of 76% of that of the normal radius by 12 weeks. Conclusion The composite of rhBMP-2 and gelatin has satisfactory activity of bone induction, and 1.0 mg rhBMP-2 can repair of 15 mm bone defect in rabbit's radius.