Bioactive glasses have been developed within the last five decades and are typically based on variations of a soda-lime phospho-silicate composition proposed by Hench. Thus, numerous melt-derived glasses with compositions in the system Na2O-CaO-SiO2-P2O5 as well as variations thereof containing additional cations and anions (e.g., Mg2+, Sr2+, Zn2+, F− etc.) were reported to exhibit bioactivity.
Recently, we have reported the synthesis of Mg- and Ca-containing silicon oxycarbide glasses which were prepared from a polysiloxane-based single-source precursor and exhibited bioactivity. The synthesized materials have highly connected structural network with an open architecture and a minor but critical fraction of depolymerized Q-species. This combination of structural features was shown to be responsible for providing bioactivity in SiOC-based glasses at the same time with an enhanced thermo-mechanical robustness and crystallization resistance.
In the present study, Ca- and/or B-containing SiOC-based glasses were prepared using a polymethylsilsesquioxane preceramic polymer which was modified with calcium acetylacetonate and/or boric acid. Thermal treatment of the prepared precursors at 1100 °C in inert gas atmosphere led to SiBOC, SiCaOC and SiCaBOC glasses. The prepared glasses were structurally characterized by using various spectroscopic methods. Moreover, the prepared glasses were assessed with respect to their bioactivity upon exposure to simulated body fluid (SBF) at 37 °C. Microscopic and spectroscopic methods were used in order to rationalize the biomineralization of hydroxyapatite on the surface of the prepared glasses and correlate this with their structural features.