Structural, physico-mechanical and in-vitro bioactivity studies on SiO 2 -CaO-P 2 O 5 -SrO-Al 2 O 3 bioactive glasses.

Strontium based bioactive glasses have shown a better biocompatibility than calcia based bioactive glasses. In this report, we have shown that the bioactivity is found to be even more when we incorporate Al2 O3 upto 1.5 mol% in SiO2 -CaO-P2 O5 -SrO bioactive glass. We have studied the structural, physico-mechanical and bioactive properties in these glasses with varying alumina concentration from 0.5 to 2.5 mol%. The bioactivity of the glasses is evaluated by in vitro test in simulated body fluid (SBF). The formation of hydroxy carbonated apatite layer (HCA) on the surface of glasses after immersion in SBF is identified by the XRD, FTIR and SEM. The substitution of Al2 O3 for SrO in these glasses demonstrates a significant enhancement in compressive strength and elastic modulus. However cytotoxicity and cell viability assessed using human osteosarcoma U2-OS cell lines show the growth of the cells without causing any significant loss of viability and cell death upto 1.5 mol% addition of Al2 O3 . Osteosarcoma cells grow on the surface of bioglasses which make them biocompatible and fit for use in clinical trials.