Development of biocompatible metal-BMP composit

为了制备水溶性BMP，先进行S-200凝胶过滤，然后切断分子量大于40000 Da的蛋白。将1万~ 3万Da的馏分对水透析，离心出ppt。冻干上清液。这是水溶性BMP。将这种BMP与粉末纯金属（Ag、Al、Au、Co、Cr、Cu、Fe、Ge、In、Ir、Mn、Mo、Ni、Pb、Pd、Pt、Sb、Sn、Ta、Ti、W、Zn）结合，然后研究每种金属对新骨形成的影响。在Au，Mo，Ti的植入过程中，这些金属的存在对新骨形成没有抑制作用。相反，Cu、Fe、Sb明显抑制骨诱导，新骨形成不完全。使用其他金属，可以观察到新骨的形成，但新骨的数量减少了。测定Au、Pt、Ni、ti、Au、Pt对[3H]-胸腺嘧啶、[35]-硫酸根的摄取，了解DNA合成，GAG（糖胺聚糖）定量分析细胞毒性和软骨形成。Ti对DNA合成无明显抑制作用，而Ni有明显抑制作用。在GAG合成中也得到了同样的现象。在某些条件下，铂对骨活性有轻微的抑制作用，但在通常的实验条件下，它对新骨的形成没有影响。因此，金铂合金似乎是发展生物相容性合金的一个很好的候选者。在Au-Pt中加入Mo是一种很好的改性剂。如前所述，Ti作为生物相容性金属表现出优异的性能。

In order to prepare water soluble BMP,S-200 gel filtration was performed, then higher molecular weight than 40,000 Da was cut off. The fraction of 10,000-30,000 Da was dialyzed against water and centrifuge out the ppt. The supernatant was lyophilized. This was water soluble BMP.This BMP and powdered pure metals(Ag,Al,Au,Co,Cr,Cu,Fe,Ge,In,Ir,Mn,Mo,Ni,Pb,Pd,Pt,Sb,Sn,Ta,Ti,W,Zn)were combined, then the effect of each metals on new bone formation was investigated. In the implantation of Au,Mo,Ti, there were no inhibition of new bone formation under the existence of these metals. On the contrary, Cu,Fe,Sb suppressed osteoinduction remarkably and new bone formation did not occur completely. With other metals, new bone formation were observed but the amounts of new bone were decreased. Uptake of [3H]-thyamidine, [35]-sulfate were measured to know the DNA synthesis, GAG (glycosaminoglycan) for the quantitative analysis of cytotoxity and chondrogenesis by Au,Pt,Ni,Ti.Au,Pt.Ti did not suppress the DNA synthesis, and Ni did remarkably. Same phenomena was obtained in GAG synthesis. In some condition Pt inhibit osteoactivity slightyl, however in usual experimental condition, it did not effect on new bone formation. Consequently, Au-Pt alloy seems to be a excellent candidate for the developing biocompatible alloy. Addition of Mo to Au-Pt will be a good modification. Ti showed excellent property for a biocompatible metal mentioned as previously.