Biomimetic Nanophotosensitizer Amplifies Immunogenic Pyroptosis and Triggers Synergistic Cancer Therapy.

Immunotherapy is considered to be an effective treatment for cancer and has drawn extensive interest. Nevertheless, the insufficient antigenicity and immunosuppressive tumor microenvironment often cause unsatisfactory therapeutic efficacy. Herein, a photo-activated reactive oxygen species (ROS) amplifying system (defined as "M-Cu-T") is developed to induce antitumor immune response by triggering a tumor-specific immunogenic pyroptosis. In M-Cu-T, M1 macrophage membrane-based vesicles are used for drug loading and tumor targeting, photosensitizers (meso-tetra(4-aminophenyl) porphyrin, TAPP) are used as a pyroptosis inducer, copper ions (Cu ) can enhance ROS-induced pyroptosis by consuming antioxidant systems in cells. As expected, the prepared M-Cu-T targets enrichment into tumor cells and cascades the generation of ROS, which further induces pyroptosis through caspase 3-mediated gasdermin E (GSDME) cleavage under laser activation. The pyroptotic cancer cells accompanying secrete related pattern molecules, induce immunogenic cell death, and activate antitumor immunity for immunotherapy. An effective tumor ablation is observed in LLC and CT26 cancer mouse models. This study provides inspiration for boosting the immunogenicity and achieving satisfactory therapeutic effects in cancer therapy.