Design strategies for aggregation-induced emission photosensitizers with enhanced safety in photodynamic therapy

Photodynamic therapy (PDT) is emerging as a powerful tool in tumor treatment due to its unique advantages of being minimally invasive and universally applicable. Photosensitizers (PSs) play a crucial role in PDT, and those with aggregation-induced emission (AIE) have been developed to enhance fluorescence and improve photosensitization under physiological conditions for image-guided PDT. However, the non-specific distribution of PSs during PDT and their prolonged retention in the body after PDT can result in damage to normal tissues upon exposure to light, leading to the occurrence of severe side effects. Therefore, this review systematically summarized the latest advances in designing new AIE PSs to enhance the safety of PDT. In particular, some strategies of targeted PSs, responsive turn-on PSs, and two-photon excitable PSs to enhance the intraoperative safety, as well as the strategy of degradable PSs to enhance the postoperative safety were focused.