Preparation and Characterization of Silver-Doped Nanobioactive Glass Particles and Their In Vitro Behaviour for Biomedical Applications

In this study, silver-doped silica- and phosphate-based nanobioactive glass compositions (58SiO(2)-(33 - x)CaO-9P(2)O(5)-xAg(2)O) (x = 0, 0.5, 1, 2 and 3 mol%) were synthesised by a simple and cost-effective sot-gel method. The prepared samples were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and energy-dispersive X-ray fluorescence spectrometer studies. All the compositions of the glass samples revealed amorphous phase with spherical morphology and a particle size less than.100 nm. The prepared glass samples reveal the specific surface area in the range of 55.31-90.69 m(2) g(-1). The bioactivity of glass samples was confirmed through the formation of the hydroxyapatite layer on glass surfaces during in vitro studies in which silver doped glasses (2 and 3 mol%) showed better bioactivity. A better biocompatibility was achieved in human gastric adenocarcinoma cell line in case of silver-free glass sample while comparing the biological behaviour of Ag2O-doped glasses. Further, the Ag2O-doped nanobioactive glasses revealed significant antibacterial activity against Staphylococcus aureus and Escherichia coli. Ag2O substitutions showed better in vitro bioactivity and remained slightly toxic to human cells at a concentration of 100 mu g mL(-1). Silver-doped nanobioactive glass shows good antimicrobial property as well as no significant toxic for implant applications.