Gamma irradiation effectuality on the antibacterial and bioactivity behavior of multicomponent borate glasses against methicillin-resistant Staphylococcus aureus (MRSA).

Recently some borate bioactive glasses have been discovered to have an antibacterial effect when interacting with pathogenic bacteria. In this study, borate bioactive glasses (BG) doped with metal oxide (MO) ZnO, TiO2, TeO2, and CeO2 (encoded BG-Zn, BG-Ti, BG-Te, and BG-Ce, respectively) were prepared using the melt-quench method and have been characterized before and after gamma irradiation at 25.0 kGy. X-ray diffraction was performed to recognize the amorphous phases of all samples. Infrared absorption of glasses confirms vibrational bands in their wave number according to mixed main triangular and tetrahedral borate groups. After immersion in the simulated body fluid (SBF) solution, two characteristic peaks are generated indicating the bioactivity of the studied glasses through the formation of hydroxyapatite. SEM micrographs of glass after immersion display that the crystalline phases are identified to be more distinct in different shapes because of the multi-composition involved. The antibacterial activity of borate glasses was assessed against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 6538. The antibacterial results showed that BG-Te was  the most efficient against S. aureus ATCC 6538. Furthermore, BG-Te reduced biofilm production (79.23%) at the concentration of 20.0 mg/mL. (BG-Te) at 20.0 mg/mL significantly decreased the viability percent, cell count, protein content, and protease activity of S. aureus cells. BG-Te presents powerful activity against bacterial infections. It was necessary to equilibrate the antibacterial efficiency with the biocompatibility, so the MTT assay confirmed that BG-Te has low cytotoxicity on the human fibroblast cells (WI-38). It is expected that borate bioglass contained TeO2 could be a promising biomaterial for bone tissue engineering.