Effects of TiO2-containing phosphate glasses on solubility and in vitro biocompatibility

Phosphate‐based glasses with different amounts of titanium dioxide (TiO2), having the following molar composition 50P2O5‐30CaO‐9Na2O‐3SiO2‐3MgO‐(5‐x)K2O‐xTiO2, (where x = 0, 2.5, 5 mol %), were synthesised and characterized in terms of solubility (according to ISO 10993‐14), and in vitro biocompatibility using human MG‐63 osteoblast cells. Dissolution tests were carried out in Tris‐HCl (pH 7.4) to simulate the physiological pH and in citric acid (pH 3.0) to simulate an acidic environment. The weight loss decreased with increasing TiO2 content, a process further enhanced in acidic medium. TiO2 reduced the pH changes usually caused by the dissolution products released. Cellular tests showed that all the glasses studied (0–5 mol % TiO2) and TiCl4, used to investigate the biocompatibility of titanium ions, did not produce cytotoxic effects on human MG‐63 osteoblasts for up to 5 days in culture. On the basis of these results, we suggest that TiO2‐containing phosphate glasses could be promising substrates for bone tissue engineering applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011.