Metal-based nanomaterials for cancer phototherapy: current advancements and translational challenges

Cancer remains a leading global health challenge, with limitations in chemotherapy, radiotherapy, and immunotherapy driving interest in alternative modalities. Phototherapy, comprising photodynamic therapy and photothermal therapy, has shown promising antitumor efficacy, yet conventional photosensitizers and photothermal agents often suffer from poor stability, limited tissue specificity, and suboptimal in vivo performance. Metal-based nanomaterials effectively address the above limitations and bottlenecks by providing tunable optical properties, catalytic activity for reactive oxygen species generation, and multifunctional platforms for imaging and combination therapies. In this review, we systematically discuss recent advances in precious metal and non-precious metal nanomaterials for cancer phototherapy, elucidating their diverse mechanisms of action and anticancer efficacy, and highlighting the pivotal role of materials design in performance optimization. We further summarize strategies to design and improve these nanomaterials, with an emphasis on enhancing biocompatibility, tumor targeting, and photothermal conversion efficiency, all of which are critical for clinical translation. We also highlight synergistic therapeutic paradigms that combine metal-based phototherapy with other anticancer modalities, providing representative examples of how such combinations can improve treatment outcomes. Finally, we discuss future directions, particularly the development toward intelligent, multifunctional, and low-toxicity metal-based nanoplatforms through stimulus-responsive designs, functional integration, green synthesis, and artificial intelligence-assisted approaches. Overall, this review aims to provide a solid theoretical and technical reference to accelerate the clinical application of metal-based nanomaterials in cancer phototherapy.