Programmable Tumor-Activated NanoCRISPR Platform Synergizes cGAS-STING Activation With PD-L1 Blockade for Potentiated Antitumor Immunity

The cGAS-STING pathway is an essential element of antitumor immunity. However, its activation triggers immunosuppressive molecules like PD-L1 to feedback upregulate, which limits therapeutic efficacy. Herein, we develop a programmable tumor-activated nanoCRISPR platform (PATROL) that co-delivers CRISPR/Cas13a-CARM1 plasmid and PD-L1 blocking peptide to stimulate the cGAS-STING-IFN-I pathway and diminish its immunosuppressive feedback loop, thereby improving antitumor efficacy. PATROL achieves enhanced circulation longevity, tumor-targeting specificity, and tissue penetration due to surface modifications such as PEGylation, hyaluronic acid, and TAT peptide. At the same time, its PD-L1 blocking peptide on the surface facilitates drug accumulation with the tumor and inhibits PD-L1 activity. Following exposure to tumor-associated hyaluronidase, PATROL undergoes enzyme-triggered disassembly, surface charge reversal, rapid lysosomal escape, and significant CARM1 knockdown, leading to enhanced cGAS-STING signaling. This bifunctional approach cooperatively reprograms the immunosuppressive tumor microenvironment, increases cytotoxic T lymphocyte infiltration, and elicits powerful antitumor immunity by simultaneously blocking PD-1/PD-L1 signaling and activating the cGAS-STING-IFN-I pathway. PATROL exhibits significant antitumor efficacy in B16-F10 melanoma models, successfully inhibiting tumor growth and prolonging survival. As consequently, PATROL presents an innovative therapeutic strategy that achieves effective tumor suppression by enhancing antitumor immunity through dual-pathway activation.