Organic small molecule-based photothermal agents for cancer therapy: Design strategies from single-molecule optimization to synergistic enhancement

Organic photothermal agents have received increasing attention in the past few decades due to their excellent biocompatibility and flexible chemical modification and functionalization in cancer photothermal therapy (PTT). Various organic small molecule-based photothermal agents with potential for future clinical applications have been developed. In this review, we summarize the design strategies to improve the individual capabilities of organic small molecule-based photothermal agents, collaborative strategies for the enhancement of PTT based on organic small molecules, and other organic photothermal agents with special structures, including porphyrin, metal complexes, and metallacycles. The prospects and challenges associated with organic small molecule-based photothermal agents for successful clinical applications are also discussed.