Structural phase formation and in vitro bioactivity evaluations of strontium phosphosilicate for orthopedic...

Structural features of apatites make them one of the most promising candidates for bone tissue regenerative applications. The unique structure and availability of mobile Metal ion as well as other components help interaction with biological fluids and can promote as well as stimulate bone regeneration with correct components. The present study focusses on Strontium phosphosilicate, an apatite analogue to Calcium phosphate-based HAP only loaded with better composition replacing Calcium with stimulatory Strontium and co-existent Silicate alongside phosphate both known to stimulate osteogenesis. Bulk particles were synthesized as powders with Acidic medium as well as the Basic medium of reaction mixture via Sol-Gel and Co-precipitation techniques respectively and phase formation was studied with respect to temperature further detailed by TGA-DSC studies. Secondary phases were also indexed based on which Acidic medium samples sintered at 800°C were comparatively better from the Basic medium on account of the presence of silicate phase forming agglomerated Strontium phosphosilicate. Hemolysis assay and MG-63 based cytotoxicity assay were carried out to study biocompatibility and antibacterial properties were also elucidated in Gram-positive and Gram-negative bacteria. Apatite seeding and bone mineralization studies were carried out with Simulated body fluid and characterized structurally and morphologically.