Injectable bone paste biocomposite based on melt-derived bioactive glass and sodium alginate natural polymer

In this study, melt-derived bioactive glass powder was mixed with different concentration of sodium alginate solution to prepare injectable pastes. Injectability of the pastes was investigated using needles with different tip diameter. Rheological measurements were performed both in rotatory and oscillatory modes. Washout resistance was evaluated through soaking pastes in simulated body fluid under dynamic condition. The ability of in vitro apatite formation was also studied in simulated body fluid using XRD, FTIR and SEM techniques. Sodium alginate increased injection force although all pastes could be injected completely through standard syringe. Biocomposite pastes exhibited thixotropic and shear thinning behaviour. The solid nature of pastes overcomes its liquid nature at all frequencies. This paste did not disintegrate in simulated body fluid, moreover apatite phase was precipitated on its surface after 21 days. Overall, the results confirm that bioactive glass/sodium alginate composite may be successfully used in the treatment of bone injuries.