脱钙骨颗粒骨水泥骨形成蛋白复合材料配方优化研究

目的 探讨脱钙骨基质颗粒（DBM）、骨水泥（BC）、牛骨形成蛋白（bBMP)的最佳比例和最方便的复合方法。方法 提取bBMP,制备狗DBM,二者按1：25的质量比用直接掺合法和吸附法复合后,再用BC按不同的质量比复合,将复合后的材料行体外生物力学测定和扫描电镜观察,体内成骨诱导活性测定和植入实验。结果 bBMP与DBM直接掺合和吸附法复合后,所得材料的成骨诱导活性无差别。复合材料中DBM的质量比≤40%时,材料内部的大部分间隙＜100μm,空隙率＜20％,不利于新生血管长入和新骨形成。DBM的质量比≥80％时,DBM和BC不能复合在一起,从而失去塑形性,DBM的质量比在50％－75％的范围内,随DBM质量比的增加生物力学强度逐渐降低而成骨诱导和血运重建的质量越好。结论 bBMP与DBM复合以直接掺合法最方便而不影响复合材料的成骨诱导活性。DBM的质量比为50％－60％时,复合材料既具有相当的生物力学强度,又利于诱导新骨形成和血运重建,适宜于修复承重部位的骨缺损,比例为75％时可用于修复非承重部位的骨缺损。

Preparation of decalcified bone matrix, bone cement and bone morphogenetic protein composite

OBJECTIVE: To investigate the most excellent composite proportion and the most convenient composite method of decalcified bone matrix (DBM), bone cement (BC) and bovine bone morphogenetic protein (bBMP) composite. METHODS: The canine DBM and the bBMP were prepared beforehand. First mix the bBMP and DBM together with the proportion of 1:25 with adsorption and directly, then add BC with different weight proportion and finally the complex material was examined by biomechanics, scan electron microscope, determination of bone inductive activity and implanted into the canine femoral defect caused by microwave-induced hyperthermia. RESULTS: The bBMP had strong bone inductive activity and had no affect for this function when combined with DBM with different method. There were irregular gaps in the composite and most of them with diameter less than 100 microns and the porosity of the composite was less than 20% when the proportion of DBM was 40%. So it was unfavorable for the new bone to form and the new blood vessels to reconstruct. The DBM and BC could not be combined together when the proportion of DBM was 80%. While the biomechanical intensity of the composite decreased and the qualities of the new bone forming and new blood vessels reconstructing improved successively when the proportion of DBM was from 50% to 75%. CONCLUSION: It is the most convenient that bBMP is combined with DBM directly while its bone inductive activity could not be affected. The composite material not only has high biomechanical intensity, but also is favorable for new bone to form and new blood vessels to reconstruct when the proportion of DBM is 50% and 60%. So it is favorable for bone repair in the places where need to bear a load. However it is also favorable for bone repair in the places where do not need to bear a load when the proportion of DBM is 75%.