Dual-modality treatment using gamma radiation and ZnO nanoparticles: effects on normal and malignant lung cells

This study primarily aims to investigate the effects of gamma (γ) radiation, both independently and in combination with zinc oxide nanoparticles (ZnO NPs), on normal and lung cancer cell lines. Lung cancer continues to be a major cause of cancer-related mortality globally. Radiotherapy is a common way of treating lung cancer. The treatment efficacy of cell death requires a high dosage of focused radiation. Due to their physicochemical properties and potential biological activity, ZnO NPs have emerged as promising candidates in nanomedicine and oncology. In this research, ZnO NPs were synthesized and characterized through various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), and dynamic light scattering (DLS). The resulting nanoparticles were semi-spherical in shape (22-29 nm), stable, and had a zeta potential of - 21 ± 2.40 mV. The cytotoxic effects were assessed using human lung cancer cells (A549) and normal lung fibroblast cells (WI-38). Treatments involved ZnO NPs alone or combined with 15 Gy of γ-radiation over 48 h. A significant increase in cytotoxicity was observed in A549 cancer cells compared to normal cells. ZnO NPs alone showed moderate anticancer efficacy with an IC50 of 26.78 ± 0.44 µg/mL, whereas ZnO NPs + 15 Gy gamma radiation led to a pronounced reduction in cell viability with an IC50 of 15.97 ± 0.45 µg/mL. These results indicate that the combination of ZnO NPs with γ-radiation enhances apoptosis and significantly suppresses the growth of lung cancer cells (p < 0.001), offering potential for improved therapeutic outcomes in lung cancer radiotherapy.