Evaluation of physico-chemical, antioxidant and antibacterial properties of ZnO added fluorophosphate glasses

This investigation aimed to study the effects of ZnO-added fluorophosphate glass on in vitro degradation, apatite- forming ability, cytotoxicity, antioxidant efficacy, and antibacterial activity. In this regard, fluorophosphate glasses with varying zinc oxide (ZnO) content (0, 1, 2, 4, and 8 mol%) were synthesized by the standard melt quenching technique and subsequently in vitro degradation of the glass samples was analyzed by water solubility test. The apatite-forming ability of the glasses was studied by simulated body fluid (SBF) immersion analysis. Variations in the elemental and structural properties of the glasses before and after SBF immersion were assessed using an X-ray diffractometer, a Fourier transform infrared spectrometer, and a scanning electron microscope coupled with energy-dispersive X-ray spectrometer. The cytotoxicity assessment for ZnO-added fluorophosphate glasses was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The antioxidant efficacy of the glass samples was evaluated using 2,2-diphenyl-1-picrylhydrazyl assay. Variations were observed in lower concentrations of ZnO compared to higher concentrations in mechanical, structural, and biological properties. Amongst the concentrations, 2 mol% ZnO-added fluorophosphate glass demonstrated superior antioxidant activity compared to the zinc-free fluorophosphate glass. The optimized 2 mol% of ZnO was evaluated against different bacterial strains such as Escherichia coli, , Klebsiella pneumonia, , Proteus vulgaris, , Staphylococcus epidermidis, , Pseudomonas aeruginosa, , and Staphylococcus aureus using the agar diffusion method. A distinct transparent inhibitory zone was observed against all the bacterial strains, following exposure to the 2 mol% of ZnO containing fluorophosphate glass compared to the zinc-free glass sample. These findings suggest that 2 mol% of ZnO containing fluorophosphate glass is well-suited for biomedical applications involving cellular activity.