A NIR‐II Fluorescent PolyBodipy Delivering Cationic Pt‐NHC with Type II Immunogenic Cell Death for Combined Chemotherapy and Photodynamic Immunotherapy

Abstract Tumor immunotherapy has emerged as one of the most promising clinical techniques to treat cancer tumors. Despite its clinical application, the cancerous immunosuppressive microenvironment limits the therapeutic efficiency of the treatment. To generate a stronger immunogenic therapeutic effect, herein, a platinum complex for chemotherapy and a BODIPY photosensitizer for photodynamic therapy are encapsulated into multimodal type II immunogenic cell death (ICD) induce nanoparticles. As the platinum complex and the photosensitizer are able to induce type II ICD, an exceptionally strong immune response is observed in triple‐negative breast cancer cells. While remaining stable and therefore poorly cytotoxic in the dark, the nanomaterial is found to quickly dissociate upon exposure to near‐infrared light, causing a multimodal mechanism of action in cancer cells as well as multicellular tumor spheroids through combined chemotherapy, photodynamic therapy, and immunotherapy. The nanoparticles are found to nearly fully eradicate a triple‐negative breast cancer tumor and therefore to strongly enhance the survival of tumor‐bearing mice models using low drug and light doses.