Effect of Boron Addition on the Thermal, Degradation, and Cytocompatibility Properties of Phosphate-Based Glasses

摘要

In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P2O5)45-(CaO)16-(Na2O)15-x -(MgO)24-(B2O3)x system and four in the system (P2O5)50-(CaO)16-(Na2O)10-x-(MgO)₂₄-(B₂O₃)_x, where x = 0,1, 5 and 10 mol%. The effect of B₂O₃ addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B₂O₃ increased the glass transition (T _g), crystallisation (T _c), melting (T _m), Liquidus (T _L) and dilatometric softening (T _d) temperature and molar volume (V _m). The thermal expansion coefficient (α) and density (ρ) were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, T _c,ons minus glass transition temperature, T _g), and an increase in the processing window was observed with increasing B₂O₃ content. Degradation studies of the glasses revealed that the rates decreased with increasing B₂O₃ content and a decrease in degradation rates was also observed as the P₂O₅ content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B₂O₃.