The Development for Osteoinductive and Biodegradable Bone Substitute Materials

口腔颌面部发生骨缺损的病例很多，如囊肿、癌症等。因此，临床需要骨形态发生蛋白(BMP)。人们对骨形态发生蛋白的纯化和生理功能进行了大量的研究。有报道认为，脱钙骨基质中的BMP(Ostegenin，BMP-3)具有比rhBMP-2更强的诱导成骨活性的可能性。经Sephacry1 S-200HR凝胶过滤、Mono-S阳离子交换、肝素亲和层析、C_1/8反相层析等步骤，从脱矿骨提取液中分离纯化骨形态发生蛋白。本实验制备的骨形态发生蛋白制剂植入胸腔皮下组织后2周内即可诱导出异位骨和骨髓组织。15%的SDS-PAGE结果表明，还原条件下的相对分子质量是未还原条件下的一半。多肽序列分析表明，纯化的BMP组分含有Wozney等报道的BMP-3。将直径8 mm的颅骨缺损制成含有BMP的多孔L聚乳酸圆盘植入其中。通过软X射线像、钙含量和组织学观察来评价其诱导成骨活性。植入2周后，诱导形成骨组织，摘除的盘中可见大量钙离子存在。植入4周后，同样诱导出骨组织，并从摘除的盘中检测到较大的钙值。这些结果支持了多孔聚L-乳酸盘在骨缺损修复中的作用。

There are many cases to make bone defects in the oral and maxillo-facial region, for example cysts, cancers and so on. So Bone Morphogenetic Protein (BMP) is needed for clinical usage. And a lot of studies have been done to purify the BMP and to investigate the physiological function of that. Several reports suggested the possibility that BMP (Osteogenin, BMP-3 from demineralized bone matrix have stronger osteoinductive activity rather than rhBMP -2. Therefore the BMP was purified from the demineralized bone extract by gel filtration on Sephacry1 S-200HR, cation exchange with Mono-s, Heparin affinity column and finally by c1/8 reverse phase chromatography. The BMP preparation obtained in this study induced ectopic bone and marrow tissue in ectopic site in 2 weeks after implantation into the thoracic subcutaneous tissue. The results of 15% SDS-PAGE revealed the molecular weight in reduced condition is half that in non-reduced condition as reported before. Peptide sequence analysis revealed that the purified BMP fraction contained "BMP-3" reported by Wozney et al.A skull defect which is 8 mm in diamenter was prparated, and porus poly-L-lactic acid disc including the BMP was implanted into the defect. Osteoinductive activity induced by the disc was evaluated by means of soft X-ray image, calcium content, and histological observation. 2 weeks after implantation, bone tissue was induced and large value of calcium was detected in the excised discs. 4 weeks after implantation, also bone tissue was induced and larger value of calcium was detected from the excised discs. These results supported that the porus poly-L-lactic acid disc will be effective for recovery of bone defect.