Formation of apatite nano-needles on novel gel derived SiO2-P2O5-CaO-SrO-Ag2O bioactive glasses

A novel SiO2-P2O5-CaO-SrO-Ag2O bioactive glass containing from 0 to 10 mol% Ag2O was produced via the sol-gel method. The influence of silver content on in vitro hydroxyapatite (HA) formation, antibacterial and cell viability properties were investigated. The apatite shape and structure were evaluated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The results demonstrated that the rate of formation of crystalline HA on SiO2-P2O5-CaO-SrO-Ag2O bioactive glass containing 5% Ag2O (BG-5A) was higher in comparison with other specimens. Formation of apatite nano-needles on the SiO2-P2O5-CaO-SrO-5%Ag2O surface in vitro, after 3 days soaking in SBF solution, demonstrated high bioactivity. The alkaline phosphatase (ALP) and 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay evaluation methods illustrated that the presence of low silver (3% and 5% Ag2O) had stimulating effect on promoting both differentiation and proliferation of G292 osteoblastic cells. Finally, results offer that specimen BG-5A is well candidate for bone tissue application with considerable high antibacterial potential, bioactivity and optimal cell viability.