Filgueiras M R, LaTorre G, Hench L L
Advanced Materials Research Center, University of Florida, Gainesville 32615.
J Biomed Mater Res. 1993 Dec;27(12):1485-93. doi: 10.1002/jbm.820271204.
The in vitro five-stage surface reactions of two bioactive glass compositions, 45S5 and 52S4.6, and one bioinert glass, 60S3.8, exposed to three simulated body fluids (SBF) were analyzed using Fourier Transform infrared Spectroscopy (FTIR). There was little effect of SBF composition on ion exchange, silica hydrolysis, and silica polymerization (stages 1-3) of glass with silica content up to 52 wt%. However, calcium and phosphate ions in SBF accelerated the formation of an amorphous calcium-phosphate (a-CP) layer (stage 4), and crystallization (stage 5) of the hydroxycarbonate apatite (HCAp) layer. The magnesium ions had a retardation effect on the kinetics of stages 4 and 5, but little effect on stages 1-3. In SBF solutions which contained calcium and phosphate ions an amorphous calcium-phosphate (a-CaP) layer formed on even a 60S3.8 glass which was not bioactive in vivo. However, the a-CaP layer did not crystallize to form HCAp. Thus, there is a significant contribution from the ions present in the SBF solutions to the HCAP formation and crystallization of HCAp on bioactive glasses. Also, silanol repolymerization is necessary for rapid crystallization of HCAp.
使用傅里叶变换红外光谱（FTIR）分析了两种生物活性玻璃成分（45S5和52S4.6）以及一种生物惰性玻璃（60S3.8）在体外与三种模拟体液（SBF）发生的五阶段表面反应。对于二氧化硅含量高达52 wt%的玻璃，SBF成分对离子交换、二氧化硅水解和二氧化硅聚合（第1 - 3阶段）几乎没有影响。然而，SBF中的钙和磷酸根离子加速了无定形磷酸钙（a-CP）层的形成（第4阶段）以及羟基碳酸磷灰石（HCAp）层的结晶（第5阶段）。镁离子对第4和第5阶段的动力学有阻滞作用，但对第1 - 3阶段影响很小。在含有钙和磷酸根离子的SBF溶液中，即使是在体内无生物活性的60S3.8玻璃上也会形成无定形磷酸钙（a-CaP）层。然而，a-CaP层并未结晶形成HCAp。因此，SBF溶液中存在的离子对生物活性玻璃上HCAp的形成和结晶有重要贡献。此外，硅醇再聚合对于HCAp的快速结晶是必要的。
