Synergistic Photodynamic Therapy: Copper-Cysteamine Nanoparticles and UV Radiation Suppress Melanoma (A375)

Conventional melanoma cancer treatments, including surgery, radiotherapy, and chemotherapy, are often costly and associated with adverse effects such as tissue damage, pigmentation changes, pain, inflammation, and prolonged recovery. Hence, this study explores photodynamic therapy (PDT) using copper-cysteamine nanoparticles (Cu-Cy NPs) combined with UVA irradiation as a potential approach to enhance therapeutic efficacy while reducing side effects. A375 melanoma cells were treated with Cu-Cy NPs (3 μg/mL) and exposed to UVA light for 2 or 10 minutes. Cell viability, ROS generation, and apoptosis were evaluated using MTT, NBT, and flow cytometry assays, respectively. Neither Cu-Cy NPs nor UVA irradiation alone significantly increased ROS or apoptosis. However, their combination for 10 minutes synergistically elevated ROS levels and induced pronounced apoptosis, with cell death comparable to cisplatin-treated positive controls. Shorter UVA exposure (2 minutes) did not produce a significant effect, indicating the critical role of irradiation duration. Comparative analysis across cell lines confirmed that A375 cells exhibit high sensitivity to UVA-mediated PDT, highlighting cell-line-specific differences in response. The combination of UVA irradiation and Cu-Cy NPs effectively induces apoptosis in melanoma cells, highlighting a synergistic effect that surpasses individual treatments. This approach represents a potential alternative or adjunct to conventional therapies, with the advantage of minimizing adverse effects.