Preparation and Rheological Properties of Bioactive Glass-Polyvinyl Alcohol Nanocomposites to Repair Bone Defects

Bioactive glasses with different compositions have been extensively used as substitute for defective bones. Injectable biomaterial is important in clinical applications that involve defects with limited accessibility or when using minimally invasive surgical techniques. In this study bioactive glass nano-powder was synthesized by acid-base catalyzed sol-gel process and used as solid phase of injectable non-setting pastes. Morphological characteristics of powder were found by TEM. To prepare paste the powder was mixed with hyaluronic acid and polyvinyl alcohol solutions. Stability of pastes was determined by soaking in simulated body fluid. Rheological behaviours of paste in both rotation and oscillation modes were also measured. The results showed that particle size of glass powder was 20-30 nm. According to rheometry, these nano composites exhibited non-Newtonian shear thinning behaviour. By adding polyvinyl alcohol more stable paste with increased hysteresis loop area is obtained. The oscillatory tests revealed that these pastes were viscoelastic with more elastic character. The biocomposite can potentially be used as bioactive paste for the treatment of hard and even soft tissues.