A novel uniform monodispersed radial mesoporous bioactive glass nanosphere (MBG) with high phosphorus and calcium content has been successfully synthesized. The synthesis was first taken place in a cyclohexane-water biphasic stratification reaction system, which fabricated the radial mesoporous SiO2-P2O5 nanosphere (SPN) using hexadecyltrimethyl ammonium bromide (CTAB) as a template agent and triethanolamine (TEA) as a hydrolysis catalyst. Solid reactions were then carried out to synthesize SiO2-CaO-P2O5 MBG using SPN as both the silicon source and phosphorus source, and Ca(NO3)(2) as the calcium source. The prepared MBG not only displayed the radial structure and high specific surface area (similar to 321 m(2)/g), but also had high phosphorus and calcium content. The results of energy dispersive spectrometer (EDS) demonstrated that P2O5 content was enhanced by properly increasing the reaction temperature. The in vitro bioactivity test showed that MBG had an excellent ability of inducing apatite formation. Furthermore, the MBG showed excellent biocompatibility at a low concentration of 50-100 lg/mL in vitro, and it would have a promising prospect as drug delivery system for bone tissue regeneration. (C) 2020 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.