New sol‐gel bioactive glass and titania composites with enhanced physico‐chemical and biological properties

Abstract We developed TiO₂ matrix composites modified by sol‐gel bioactive glasses (SBG) of either high CaO content (A2) or high SiO₂ content (S2). The latter were mixed with titanium dioxide (TiO₂) at 75:25, 50:50, and 25:75 weight ratios and sintered at 1250°C for 2 h. We examined the effects of various types (A2 or S2) and compositional TiO₂:SBG ratios on the mechanical properties of resulting composites, their bioactivity and human bone marrow mesenchymal stem cells (MSC) response. The chemistry of SBGs influenced the phase composition, mechanical and biological properties of the composites. Rutile and titanite prevailed in A2‐TiO₂ composites, and rutile and crystobalite in S2‐TiO₂ composites. Compressive strength increased significantly for 25A2‐TiO₂ composites (140 MPa) compared to matrix TiO₂ (58 MPa). Composites containing 50–75 wt % of either SBG displayed bioactive properties as determined by simulated body fluid test. Compared to TiO₂, human bone marrow stromal cell (BMSC) viability was enhanced on the composites containing 25 wt % of either SBG, whereas the composites modified by 25 wt % of S2 enhanced alkaline phosphatase activity and mineralization in cultures treated with osteogenic inducers–dexamethasone (Dex) or bone morphogenetic protein. Increasing amounts of A2 in TiO₂ matrix decreased cell viability but increased collagen deposition and mineralized matrix production by BMSC. Considering the physico‐chemical and biological properties of the presented composites, the modification of TiO₂ with SBG may prove useful strategy in several bone tissue related regeneration strategies. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2383–2394, 2014.