Engineered dual-functional gold nanoparticles enhance radiosensitization in prostate cancer cells: synergistic action of curcumin and gold

Abstract

Prostate cancer remains a leading cause of cancer-related mortality in men, with the three main treatment modalities being surgery, chemotherapy, radiotherapy, or a combination depending on the stage. However, the use of radiotherapy is often restricted by dose-limiting toxicity of the organs at risk. To address this challenge, we developed curcumin-coated gold nanoparticles (Curc-GNPs) that leverage both the photoelectric properties of gold and the radiosensitizing effects of curcumin. In this study, we explore the stability, cytotoxicity, cellular uptake, and radio-sensitizing potential of Curc-GNP in PC-3 prostate cancer cells. Curc-GNPs exhibited a biphasic dose–response curve where concentrations up to 100 μg mL⁻¹ showed minimal cytotoxicity, whereas higher doses (>100 μg mL⁻¹) were markedly cytotoxic. Cellular uptake was enhanced under serum-free conditions. Clonogenic survival assays revealed significant radiosensitization (sensitizer enhancement ratio up to 1.82 at 500 μg per mL Curc-GNPs), linked to an elevated α-parameter in the linear–quadratic model and heightened reactive oxygen species production. These results highlight Curc-GNPs as a promising platform for enhancing radiotherapy efficacy in prostate cancer while potentially mitigating off-target toxicity.