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

Abstract

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.

Keywords

• Phosphate glasses
• Bioactive glasses
• Mesoporous materials
• Sol-gel processing
• lithium