Self-Guiding Polymeric Prodrug Micelles with Two Aggregation-Induced Emission Photosensitizers for Enhanced Chemo-Photodynamic Therapy

Nowadays, aggregation-induced emission luminogens (AIEgens) with reactive oxygen species (ROS) generating ability have been used as photosensitizers for imaging guided photodynamic therapy (PDT). To achieve enhanced antitumor outcomes, combining AIEgens-based PDT with chemotherapy is an efficient strategy. However, the therapeutic efficiency is hampered by the limited cellular uptake efficiency and the appropriate light irradiation occasion. In this paper, a self-guiding polymeric micelle (TB@PMPT) composed of two AIE photosensitizers and a reduction-sensitive paclitaxel prodrug (PTX-SS-N3) was established for enhanced chemo-photodynamic therapy by a dual-stage light irradiation strategy. When the micelles were accumulated in tumor tissues, the first light irradiation (L1, 6 min) was utilized to facilitate cellular uptake by ?°photochemical internalization?± (PCI). Then the intracellular glutathione (GSH) would induce the PTX release, micelles disassembly and the aggregation state change of AIEgens. The fluorescence signal change of two AIEgens-based ratiometric fluorescent probe could not only precisely guide the second light irradiation (L2, 18 min) for sufficient ROS production, but also monitor the non-fluorescent drug PTX release in turn. Both in vivo and in vitro studies demonstrated that the dual-stage light irradiation strategy employed for TB@PMPT micelles exhibited superior therapeutic effect than only 24-min continuous light irradiation.