Effects of strontium dopants on the in vitro bioactivity and cytotoxicity of strontium-doped spray-dried bioactive glass microspheres

Bioactive glass (BG) has attracted vast interest with their bioactivity and non-toxicity. In addition, studies have reported that the incorporation of metal ions is able to induce and stimulate different biological responses. Following this perspective, we demonstrated the fabrication of strontium-doped BG prepared using the spray drying method, which has the advantages of high purity and mass production capability. The characteristics of phase information and particle morphology of the BG microspheres were examined via X-ray diffractometer and scanning electron microscope, respectively. Meanwhile, in vitro bioactivity was assessed with respect to the formation of hydroxyapatite. In addition, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate the cell viability against the osteoblast cells. Finally, the results demonstrated that three morphologies were observed with their formation mechanism discussed, while positive effect of Sr dopant was shown on both in vitro bioactivity and osteoblast cell viability as compared to the un-doped BG specimen.