Novel phosphate bioglasses and bioglass-ceramics for bone regeneration

Bioactive glasses and glass-ceramics are biomaterials characterized by excellent bone bonding abilities. Many different bioactive glass formulations have been studied since the introduction of 45S5 bioglass by Larry Hench. Among silicate and borate bioglasses the phosphate-based ones seem to be interesting in drug delivery systems applications due to their high solubility and low toxicity. In this study novel phosphate bioactive glasses from the composition of P2O5 2 O 5 - CaO - Ca(OH)2 2 - KF - Na2O 2 O - TiO2 2 and P2O5 2 O 5 - CaO - Ca(OH)2 2 - ZnO - KF -TiO2 2 modified with 500 ppm or 2000 ppm of HAuCl4 4 - 3H2O 2 O were obtained by traditional melt-quenching technique. Glass crystallization temperature was measured by DSC calorimetry. The bioglasses were partially crystallized above the crystallization temperature and the bioactive glass-ceramic based on the composition of the parent glasses was obtained. The FT-IR structural studies were performed to detect the presence of structural units beneficial for bioactivity of the materials. Crystalline phases of the bioglass-ceramics were identified with XRD. All bioglassceramics contained bioactive beta- pyrophosphate. The obtained bioglasses and glass-ceramics were incubated in SBF to evaluate their bioactivity. Only P2O5 2 O 5 - CaO - Ca(OH)2 2 - KF- Na2O-TiO2 2 O-TiO 2 bioglass-ceramics developed apatite-like layer on the surface after incubation in Simulated Body Fluid and was chosen as the material for future studies. The impact of the chemical composition of the bioglass, presence of particular structural units and bioglass-ceramic phase composition on the in vitro bioactivity was discussed.