Synthesis, physico-chemical and biological characterization of strontium and cobalt substituted bioactive glasses for bone tissue engineering

• A series of strontium and cobalt containing bioactive glasses was successfully synthesized by melt-derived route.
• HCA layer was formed on all the glasses after incubation in simulated body fluid (SBF) indicating their bioactivity.
• The glasses significantly promoted osteogenic activity of human osteosarcoma cells without any cytotoxicity effect.

Due to their vast potential for repair and regeneration, different types of bioactive glasses (BGs) have been widely studied for bone tissue engineering. In this study, different groups of melt-derived bioactive glasses containing strontium (Sr2 +) and cobalt (Co2 +) ions have been designed to investigate their potential effect on increasing cell osteogenic activity. After full characterization of the synthesized bioactive glasses, they were evaluated for apatite forming ability in simulated body fluid (SBF) after different time intervals. The glasses have been examined for cell attachment and cell cytotoxicity plus their influence on osteogenic activity of the cells was analyzed by alkaline phosphatase assay (ALP) and alizarin red staining. The results show that the samples are in glassy state before immersion in SBF and an apatite-like layer has formed on the surface of SBF-immersed samples after 3, 7 and 14 days. In vitro experiments demonstrated that the incorporation of Sr2 + and Co2 + in the glass composition significantly promote osteogenic activity of human osteosarcoma cells without any cytotoxicity effect.