Development of sea urchin type silica stabilised zirconia nanospheres with enhanced antimicrobial and osteoactivity properties.

Zirconia based ceramics are giving new hope in hard tissues replacement and implants application. Among the three forms of zirconia (ZrO₂), tetragonal form (t-ZrO₂) possess high mechanical stability in comparison with the other two which makes it suitable for fabricating biomedical implants with enhanced osteo activity. Here, tetragonal phase nanospheres consisting of silica stabilised zirconia (1:1) were prepared via sol gel method. The nanospheres exhibit sea urchin type morphology as observed from FESEM analysis. XRD patterns confirm the formation of t -SiO₂-ZrO₂ binary phase after high temperature calcination at 650°C. The immersion studies in SBF help in the formation of a layer of apatite in a gradual manner over the pallets for the period of 7, 14, 21 and 28 days which was confirmed by XRD, FTIR analysis. Moreover, t- SiO₂ - ZrO₂ samples were subjected to cytotoxicity tests through MTT assay on MG-63 cell lines. Antibacterial properties were investigated quantitatively using colony forming unit method against both gram positive as well as gram-negative bacteria.