Molecular design of NIR type I phenothiazine-based photosensitizers with aggregation-enhanced ROS generation for effective photodynamic therapy applications

In this work, four phenothiazine (PHE)-based PSs (termed PPI1, PPI2, TPI1, and TPI2) were designed and synthesized by integrating various electron donor groups (pyrene, phenanthrene, terphenyl, and tetraphenylene) with PHE to regulate their donor structure. These PSs exhibit near-infrared fluorescence and aggregation-enhanced reactive oxygen species generation ability through a type I pathway, offering a potential strategy to enhance the therapeutic efficacy of PDT in cancer treatment.