Surfactant-assisted sol–gel synthesis of mesoporous bioactive glass microspheres

Abstract

Spherical mesoporous bioactive glasses in the silicon dioxide (SiO2)–phosphorus pentoxide (P2O5)–calcium oxide (CaO) system with a high specific surface area of up to 300 m2/g and a medium pore radius of 4 nm were synthesized by using a simple one-pot surfactant-assisted sol–gel synthesis method followed by calcination at 500–700°C. The authors were able to control the particle properties by varying synthesis parameters to achieve microscale powders with spherical morphology and a particle size of around 5–10 μm by employing one structure-directing agent. Due to a high calcium oxide content of 33·6 mol% and a phosphorus pentoxide content of 4·0 mol%, the powder showed very good bioactivity up to 7 d of immersion in simulated body fluid. The resulting microspheres are promising materials for a variety of life science applications, as further processing – for example, granulation – is unnecessary. Microspheres can be applied as materials for powder-based additive manufacturing or in stable suspensions for drug release, in bone cements or fillers.