Cyclodextrin-stabilized silver and gold nanoparticles induce radiosensitization of MDA-MB-231 and MCF7 breast cancer cells.

Nanomedicine highlights nanoparticles as a promising approach to improve radiation therapy, especially for breast cancer. This research investigates the impact of silver and gold nanoparticles stabilized with β-cyclodextrin (Ag-CD and Au-CD), on the X-ray susceptibility of both radiosensitive (MDA-MB-231) and radioresistant (MCF7) breast cancer cell lines. Ag-CD and Au-CD nanoparticles had an average diameter of 12 ± 3 and 16 ± 4 nm, respectively. Both demonstrated good biocompatibility with erythrocytes and peripheral blood mononuclear cells (PBMCs). NPs elevated oxidative stress following exposure to 6 Gy radiation in both cell lines. After exposure to 6 Gy, both nanoparticles led to a larger decrease in cell mitochondrial activity, as evidenced by the Alamar Blue test. At the same dose, nanoparticles raised the mRNA of SOD2 and CAT genes in MCF7 cells but lowered their expressions in MDA-MB-231 cells. Ag-CD nanoparticles induced the increase of γH2AX and 53BP1 foci formation in MDA-MB-231 cells 1 h and 24 h after 2 Gy irradiation. Au-CD nanoparticles elicited similar effects in MCF7 cells only. Both silver and gold nanoparticles efficiently induced apoptotic cell death in MDA-MB-231 cells after 6 Gy exposure. Dose-response clonogenic assay indicated significant decrease in the survival of NPs-treated cells compared to control groups. Our findings reveal that silver and gold nanoparticles stabilized with cyclodextrin can enhance radiation therapy for breast cancer. These radiosensitizing effects warrant further development of target-specific nanoparticle formulations, underscoring their potential as adjunctive agents in radiotherapy protocols.