Andersson O H, Rosenqvist J, Karlsson K H
Department of Chemical Engineering, Abo Akademi University, Turku, Finland.
J Biomed Mater Res. 1993 Jul;27(7):941-8. doi: 10.1002/jbm.820270713.
Five glass compositions in or near the bioactive region in the system SiO2-Na2O-CaO-P2O5-Al2O3-B2O3 were studied in vitro by immersion in Tris buffer. The Si concentration can be taken as a measure of the amount of dissolved glass, whereas the Na concentration can be used to estimate the thickness of the Si-rich (Si gel) layer. Upon immersing a bioactive glass into Tris buffer, a surface layer of a few micrometer thickness is dissolved during the first 8 h. During the first few hours of immersion, the rate of dissolution of the glass network is equal to or exceeds that of the growth of the Si-rich layer. If the glass contains Al2O3, most of the aluminum that would be released due to dissolution of the silica network is enriched in the Si-rich surface layer that forms due to leaching. Al2O3 is not only bonded by the Si gel but also interferes with formation of calcium phosphate.
通过将SiO2-Na2O-CaO-P2O5-Al2O3-B2O3体系中处于生物活性区域或其附近的五种玻璃组合物浸入Tris缓冲液中进行体外研究。硅浓度可作为溶解玻璃量的一种度量，而钠浓度可用于估计富硅（硅凝胶）层的厚度。将生物活性玻璃浸入Tris缓冲液后，在最初的8小时内会溶解掉几微米厚的表面层。在浸入的最初几个小时内，玻璃网络的溶解速率等于或超过富硅层的生长速率。如果玻璃含有Al2O3，由于硅石网络溶解而释放出的大部分铝会富集在因浸出而形成的富硅表面层中。Al2O3不仅与硅凝胶结合，还会干扰磷酸钙的形成。
