Persistent Luminescence Immune Hydrogel for Photodynamic‐Immunotherapy of Tumors In Vivo

Abstract Persistent luminescence material (PLM)‐based photodynamic therapy (PDT) has shown tremendous promise in tumor elimination via avoiding continuous external light illumination. In addition, the tumor‐associated antigens produced by PDT can trigger systemic antitumor immune responses, but only exhibit a limited immunotherapy effect. Herein, a persistent luminescence immune hydrogel is developed via a “turning solid into gel” strategy by introducing a PLM and an immunoadjuvant (R837) into an alginate‐Ca 2+ hydrogel for rechargeable photodynamic‐immunotherapy of tumors, for the first time. The designed PLM‐R837‐ALG hydrogel exhibits the intact persistent luminescence of the PLM, 100% of utilization efficiency of the hydrophobic precursors, good biocompatibility and syringeability, and can be easily injected into tumors to serve as an internal light source for efficiently activating photosensitizers to induce a sustained PDT effect. Moreover, the loaded R837 can significantly amplify the immunogenicity of tumor‐associated antigens originating from PL sensitized PDT, thereby leading to a powerful immune response to suppress tumors in vivo. The proposed PL‐based photodynamic‐immunotherapy provides a novel combined tumor treatment paradigm.