Kansal Ishu, Reddy AlluAmarnath, Muñoz Francisco, Choi Seong-Jun, Kim Hae-Won, Tulyaganov Dilshat U, Ferreira José M F
Department of Materials and Ceramics Engineering, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal.
Ceramics and Glass Institute (CSIC), Kelsen 5, 28049 Madrid, Spain.
Mater Sci Eng C Mater Biol Appl. 2014 Nov;44:159-65. doi: 10.1016/j.msec.2014.08.016. Epub 2014 Aug 10.
We report on the effect of sodium on the structure, chemical degradation and bioactivity of glasses in the CaO-MgO-SiO2-P2O5-CaF2 system. The (29)Si and (31)P magic angle spinning-nuclear magnetic resonance spectroscopy of melt-quenched glasses with varying Na2O/MgO ratios exhibit a silicate glass network with the dominance of Q(2)(Si) units and phosphorus mainly forming orthophosphate species. Sodium incorporation in the glasses did not induce a significant structural change in the silicate network, while it did influence the phosphate environment due to its lower ionic field strength in comparison with that of magnesium. The apatite forming ability of glasses has been investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1h and 7 days while their chemical degradation has been studied in Tris-HCl in accordance with ISO-10993-14. Increasing Na(+)/Mg(2+) ratio caused a decrease in the chemical durability of glasses and in the apatite forming ability especially during initial steps of interaction between glass and SBF solution. The cellular responses were observed in vitro on bulk glass samples using mouse-derived pre-osteoblastic MC3T3-E1 cell line. The preliminary study suggested that the increasing alkali-concentration in glasses led to cytotoxicity in the cell culture medium.
我们报道了钠对CaO-MgO-SiO2-P2O5-CaF2系统中玻璃的结构、化学降解和生物活性的影响。对具有不同Na2O/MgO比率的熔融淬火玻璃进行的（29）Si和（31）P魔角旋转核磁共振光谱显示，硅酸盐玻璃网络以Q(2)(Si)单元为主，磷主要形成正磷酸盐物种。玻璃中掺入钠不会在硅酸盐网络中引起显著的结构变化，而由于其离子场强低于镁，它确实会影响磷酸盐环境。通过将玻璃粉末浸入模拟体液（SBF）中1小时至7天的不同时间段来研究玻璃的磷灰石形成能力，同时根据ISO-10993-14在Tris-HCl中研究其化学降解。增加Na(+)/Mg(2+)比率会导致玻璃的化学耐久性和磷灰石形成能力下降，尤其是在玻璃与SBF溶液相互作用的初始阶段。使用小鼠来源的前成骨细胞MC3T3-E1细胞系在块状玻璃样品上进行了体外细胞反应观察。初步研究表明，玻璃中碱浓度的增加会导致细胞培养基中的细胞毒性。
