Cryo-Nanocatalyst Enhances Therapeutic Efficacy of Cryo-Immunotherapy through Necroptosis and Local Delivery of Programmed Death-Ligand 1 Inhibitors.

ABSTRACT

Combining cryoablation and immunotherapy presents a promising approach to revert immunosuppressive responses to solid tumors. However, challenges such as postablated residual tumors and insufficient immune activity contribute to recurrence after cryo-immunotherapy. Herein, we investigated metallic supra-structured cryo-nanocatalyst (MSCN), which features numerous ice nucleation sites and interspace loading of therapeutic agents. MSCN elevates the freezing point and enhances ice nucleation, facilitating effective ice formation during cryotreatment. MSCN-loaded tumor cells showed a 2-fold increase in cryo-cytotoxicity and undergo osmotic-related cell damage, primarily necroptosis rather than other regulated cell death mechanisms. In prostate cancer models, RNA sequencing reveals that MSCN-cryoablation promoted antitumor inflammatory pathways, including necroptosis, compared to cryoablation alone. Additionally, following programmed death-ligand 1 (PD-L1) upregulation postcryoablation, synergistic effects with PD-L1 blockade were confirmed. Given the interspace of MSCN for aPD-L1 loading, we compared the intratumoral delivery of PD-L1 blockade against systemic injection. Enhanced necrosis and necroptosis from MSCN-cryoablation and PD-L1 blockade effectively eradicated tumors and triggered antitumor and memory immune responses locally and systemically. Lastly, a spatial landscape of tumor-infiltrating immune cells was analyzed to gain insight into heterogeneous tumor responses, leading to the limitations of conventional focal ablation techniques. Our findings highlight the potential of advanced cryo-immunotherapy using cryo-nanocatalysis to promote ice formation and necroptosis, stimulating antitumor immunogenic responses.