Tumor Microenvironment-Activatable Prodrug Vesicles for Nanoenabled Cancer Chemoimmunotherapy Combining Immunogenic Cell Death Induction and CD47 Blockade.

Chemoimmunotherapy is reported to activate a robust T cell antitumor immune response by triggering immunogenic cell death (ICD), which has initiated a number of clinical trials. However, current chemoimmunotherapy is restricted to a small fraction of patients due to low drug delivery efficacy and immunosuppression within the tumor microenvironment. A tumor microenvironment-activatable prodrug vesicle for cancer chemoimmunotherapy using ICD is herein reported. The prodrug vesicles are engineered by integrating an oxaliplatin (OXA) prodrug and PEGylated photosensitizer (PS) into a single nanoplatform, which show tumor-specific accumulation, activation, and deep penetration in response to the tumoral acidic and enzymatic microenvironment. It is demonstrated that codelivery of OXA prodrug and PS can trigger ICD of the tumor cells by immunogenic cells killing. The combination of prodrug vesicle-induced ICD with Î ± CD47-mediated CD47 blockade further facilitates dendritic cell (DC) maturation, promotes antigen presentation by DCs, and eventually propagates the antitumor immunity of ICD. CD47 blockade and ICD induction efficiently inhibit the growth of both primary and abscopal tumors, suppress tumor metastasis, and prevent tumor recurrence. Collectively, these results imply that boosting antitumor immunity using ICD induction and suppressing tumor immune evasion via CD47 blockade might be promising for improved cancer chemoimmunotherapy.