Synthesis and in vitro bioactivity of CaO–SiO2–P2O5 mesoporous microspheres

In CaO–SiO2–P2O5 system, mesoporous bioactive microspheres with comparatively high P2O5 content (5 mol%–15 mol%) were successfully synthesized by co-templates of non-ionic block copolymer EO20–PO70–EO20 (P123) and cationic surfactant cetyltrimethylammonium bromide (CTAB), followed by hydrothermal and calcination treatment. The structural, morphological and textural properties were investigated by small-angle X-ray diffraction (SAXRD), transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscope and N2 sorption/desorption techniques. Results showed that the obtained microspheres with a diameter of ∼5 μm exhibit hexagonal ordered and wormlike mesostructures with certain uniformity in size and morphology. This material has BJH pore size of ∼7.3 nm and BET specific surface area of ∼618 m2/g. Samples with 15 mol% P2O5 induce apatite formation on their surface after soaked in simulated body fluid (SBF) solution for 7 d. The bioactive mesoporous microspheres could be used as a drug carrier for bone repair in future.