Synthesis of bioactive material by sol–gel process utilizing polymorphic calcium carbonate precipitate and their direct and indirect in-vitro cytotoxicity analysis

Abstract To mitigate the rising level of CO2, biological method of CO2 sequestration is one of the effective methods. Chemolithotrophic microbes are able to fix atmospheric CO2 and precipitated polymorphic minerals like calcite, vaterite and aragonite. Based on this, bioactive glass was synthesized by sol–gel process using polymorphic calcium carbonate mineral precipitated by chemolithotrophic Serratia sp. ISTD04. Characterization of bioactive material and its bioactivity was evaluated by SEM, EDX, FT-IR, XRD, ICP-MS. SEM analysis revealed biomaterial showing more bioactivity due to deposition of smaller particle like appearance throughout the surface. FT-IR analysis of sintered and immersed bioactive material indicated presence of O-Ca-O, O-Si-O and Si-O-Si functional group. The XRD analysis indicated important features similar to melt-derived Na2O-containg glass ceramics like formation of crystalline phase Na2Ca2Si3O9. Further in-vitro study was performed in simulated body fluid (SBF) and on osteosarcoma cell line, confirmed that material and their supernatant did not reflect any cytotoxicity.