Sol-gel processing and characterization of binary P2O5-CaO and ternary P2O5-CaO-Li2O mesoporous phosphate bioactive glasses

Mesoporous phosphate bioactive glasses (MPBGs) are novel and attractive biomaterials for biomedical applications. Here we report the sol-gel processing of P₂O₅-CaO and P₂O₅-CaO-Li₂O MPBGs using Pluronic P123 as the surfactant. Our results showed that P123 could act as a crystallization inhibitor, thus extending the composition range of MPBGs. The concentration of CaO from 40 to 55 mol% in P₂O₅-CaO MPBGs did not affect the phosphate chain structure and mesoporous morphology. However, the specific surface area and pore volume were slightly enhanced with the increased CaO concentration. In ternary P₂O₅-CaO-Li₂O MPBGs, the increase in Li₂O concentration (from 5 to 20 mol%) did not alter the phosphate chain structure and mesoporous morphology. However, 20 mol% Li₂O incorporation induced crystallization. Binary and ternary MPBGs showed relatively low acellular bioactivity as indicated by the slow formation of hydroxyapatite in physiological fluids. Sol-gel processing is a feasible strategy for synthesizing P₂O₅-CaO and P₂O₅-CaO-Li₂O MPBGs.