Effect of gamma irradiation on cytotoxicity and drug delivery applications of borosilicate bioactive glasses

This study investigates the synthesis and characterization of borosilicate bioactive glass with the composition [50 B2O3–5 SiO2–15 ZnO–30 CaO], focusing on the effects of gamma irradiation on its properties and drug delivery capabilities. The samples were prepared through the melt-quenching method and subjected to gamma radiation doses of 0.5, 1, and 2 mGy. Characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM/EDX), revealed that gamma irradiation increased the number of non-bridging oxygens in the glass network, enhancing its bioactivity while maintaining its amorphous structure. The cytotoxicity assay using Vero cells demonstrated improved biocompatibility with higher irradiation doses, with an IC50 value of 463.21 μg/ml for the most irradiated sample. The encapsulation efficiency of ciprofloxacin (CFX) in borosilicate glass was confirmed, showing that all samples successfully loaded the drug, with the non-irradiated sample achieving the highest efficiency (53.65%). In vitro drug release studies indicated that the release profiles conformed to the Higuchi model, highlighting sustained release characteristics, particularly in samples irradiated with 2 mGy. The research suggests that gamma-irradiated borosilicate glass may be a promising biomaterial for drug delivery applications as antibiotics in treating bacterial bone infections, providing sustained antibiotic release over extended periods.