Effect of Zn addition on sol-gel derived apatite/wollastonite glass-ceramics scaffolds

Abstract

Bioactive glasses and glass-ceramics consisting of CaO-MgO-P2O5-SiO₂ system have been shown tobe bioactive, resorbable and to exhibit appropriate mechanical properties for bone tissue engineeringapplications. Bioactive glass-ceramics scaffolds consisting of zinc doped-apatite/wollastonite (AW) glassceramicswere prepared by coating polyurethane foams with sol-gel derived glass gels. Density andcompressive strength of the scaffolds decreased with increased in zinc contents. In vitro bioactivity of ZndopedAW glass-ceramics in a simulated body fluid (SBF) showed the formation of apatite layer on thesurface within 7 days of soaking. However, increasing Zn addition increased the chemical durability of theAW glass-ceramics, resulting in a decrease in the rate of apatite formation in a simulated body fluid. Withobservation by SEM technique microstructure of pores showed interconnected macropores in the range of 300-500 ?m as depended on the type of sponge. Average pore size increased with increasing the zincadditions. Macropores and interconnect size can be tailored by controlling the zinc concentrations.