Plant-derived gold nanoparticles functionalized with pheophorbide-a for potent photodynamic therapy against A549 lung cancer cells

Lung cancer remains a leading cause of cancer-related mortality worldwide, highlighting the urgent need for more effective and safer therapeutic strategies. In this study, we investigated the potential of green-synthesized gold nanoparticles (AuNPs) conjugated with pheophorbide-a (Pheo-a) to enhance photodynamic therapy (PDT) efficacy against A549 lung cancer cells. The AuNPs-Pheo-a nanoconjugate demonstrated excellent physicochemical stability, minimal dark toxicity, and pronounced light-activated cytotoxicity in a concentration-dependent manner. Comprehensive in vitro evaluations revealed significant reductions in cell viability and metabolic activity, accompanied by increased apoptotic cell death following laser irradiation, while negligible effects were observed under dark conditions. Importantly, the nanoconjugate exhibited strong photodynamic selectivity toward cancer cells, underscoring its therapeutic potential. Overall, these findings demonstrate that green-synthesized AuNPs-Pheo-a represent a promising, biocompatible, and sustainable nanoplatform for photodynamic therapy in lung cancer, warranting further preclinical investigation.