Tulyaganov Dilshat, Abdukayumov Khasan, Ruzimuradov Olim, Hojamberdiev Mirabbos, Ionescu Emanuel, Riedel Ralf
Turin Polytechnic University in Tashkent, 17, Niyazova 100095, Uzbekistan.
Institute for Materials Science, Technische Universität Darmstadt, Jovanka-Bontschits-Strasse 2, D-64287 Darmstadt, Germany.
Materials (Basel). 2017 Nov 18;10(11):1324. doi: 10.3390/ma10111324.
This study investigates the dissolution behavior as well as the surface biomineralization in simulated body fluid (SBF) of a paste composed of glycerol (gly) and a bioactive glass in the system CaO-MgO-SiO₂-Na₂O-P₂O₅-CaF₂ (BG). The synthesis of the bioactive glass in an alumina crucible has been shown to significantly affect its bioactivity due to the incorporation of aluminum (ca. 1.3-1.4 wt %) into the glass network. Thus, the kinetics of the hydroxyapatite (HA) mineralization on the glass prepared in the alumina crucible was found to be slower than that reported for the same glass composition prepared in a Pt crucible. It is considered that the synthesis conditions lead to the incorporation of small amount of aluminum into the BG network and thus delay the HA mineralization. Interestingly, the BG-gly paste was shown to have significantly higher bioactivity than that of the as-prepared BG. Structural analysis of the paste indicate that glycerol chemically interacts with the glass surface and strongly alter the glass network architecture, thus generating a more depolymerized network, as well as an increased amount of silanol groups at the surface of the glass. In particular, BG-gly paste features early intermediate calcite precipitation during immersion in SBF, followed by hydroxyapatite formation after ca. seven days of SBF exposure; whereas the HA mineralization seems to be suppressed in BG, probably a consequence of the incorporation of aluminum into the glass network. The results obtained within the present study reveal the positive effect of using pastes based on bioactive glasses and organic carriers (here alcohols) which may be of interest not only due to their advantageous visco-elastic properties, but also due to the possibility of enhancing the glass bioactivity upon surface interactions with the organic carrier.
本研究调查了由甘油（gly）和CaO-MgO-SiO₂-Na₂O-P₂O₅-CaF₂体系中的生物活性玻璃（BG）组成的糊剂在模拟体液（SBF）中的溶解行为以及表面生物矿化情况。已表明在氧化铝坩埚中合成生物活性玻璃会因铝（约1.3 - 1.4 wt%）掺入玻璃网络而显著影响其生物活性。因此，发现氧化铝坩埚中制备的玻璃上羟基磷灰石（HA）矿化的动力学比铂坩埚中制备的相同玻璃组成的情况要慢。据认为，合成条件导致少量铝掺入BG网络，从而延迟了HA矿化。有趣的是，BG - gly糊剂显示出比制备好的BG具有显著更高的生物活性。糊剂的结构分析表明，甘油与玻璃表面发生化学相互作用并强烈改变玻璃网络结构，从而产生更解聚的网络以及玻璃表面硅醇基团数量的增加。特别是，BG - gly糊剂在浸入SBF期间具有早期中间方解石沉淀，随后在暴露于SBF约七天后形成羟基磷灰石；而BG中HA矿化似乎受到抑制，这可能是铝掺入玻璃网络的结果。本研究获得的结果揭示了使用基于生物活性玻璃和有机载体（此处为醇类）的糊剂的积极效果，这不仅可能因其有利的粘弹性性质而受到关注，还因其与有机载体表面相互作用时增强玻璃生物活性的可能性而受到关注。
