Cho S B, Miyaji F, Kokubo T, Nakanishi K, Soga N, Nakamura T
Department of Material Chemistry, Faculty of Engineering, Kyoto University, Japan.
J Biomed Mater Res. 1996 Nov;32(3):375-81. doi: 10.1002/(SICI)1097-4636(199611)32:3<375::AID-JBM10>3.0.CO;2-G.
It is known that the prerequisite for glasses and glass-ceramics to bond to living bone is the formation of biologically active bonelike apatite on their surfaces, and a certain type of hydrated silica developed on their surfaces plays an important role in nucleating the apatite. In the present study, the apatite-forming ability of silicate ion dissolved from different silica materials into a simulated body fluid was examined as follows. Polyether sulfone substrates pretreated with O2 plasma were placed in parallel to plates of three kinds of silica gels prepared in different media and silica glass, with a distance of 0.5 mm between them in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma for 4 days, and then soaked in a solution with ion concentrations 1.5 times those of the simulated body fluid for 6 days. After the first soaking, silicon combined with oxygen was detected on the surfaces of the substrates faced to all the silica gels, whereas it was not detected on that faced to the silica glass. After the second soaking, the former formed a bonelike apatite layer on their surfaces, but the latter did not. These results indicate that silicate ion which is dissolved from the silica gels and adsorbed on the substrates has an apatite-forming ability, irrespective of the microstructure of the original silica gels.
众所周知，眼镜和微晶玻璃与活骨结合的前提是在其表面形成具有生物活性的类骨磷灰石，并且在其表面形成的某种类型的水合二氧化硅在磷灰石成核过程中起着重要作用。在本研究中，按如下方式考察了从不同二氧化硅材料溶解到模拟体液中的硅酸根离子的磷灰石形成能力。将经氧气等离子体预处理的聚醚砜基底与在不同介质中制备的三种硅胶板及石英玻璃平行放置，它们之间的距离为0.5毫米，置于离子浓度与人体血浆离子浓度几乎相等的模拟体液中4天，然后浸泡在离子浓度为模拟体液离子浓度1.5倍的溶液中6天。第一次浸泡后，在与所有硅胶相对的基底表面检测到了硅与氧的结合，而在与石英玻璃相对的基底表面未检测到。第二次浸泡后，前者在其表面形成了类骨磷灰石层，而后者没有。这些结果表明，从硅胶溶解并吸附在基底上的硅酸根离子具有磷灰石形成能力，而与原始硅胶的微观结构无关。
