Near‐Infrared Triggered Cascade of Antitumor Immune Responses Based on the Integrated Core–Shell Nanoparticle.

The clinical application of antitumor immunotherapy still faces severe challenges related to efficacy. Here, a light‐triggered core–shell nanosystem is designed to boost antitumor immune response via controlled release of anti‐PD‐L1 (αPD‐L1) antibodies and enhanced antigen presentation. The nanosystem (AZ‐P@P) is constructed via integrating gold nanorods (AuNRs) as a photothermal core and zeolitic imidazolate framework‐8 (ZIF‐8) as a shell for aPD‐L1 delivery, and further PEGylating. In the nanosystem, the ZIF‐8 shell protects αPD‐L1 antibody from the complex physiological environment and hyperthermia. Once accumulated at the tumor site, AZ‐P@P under near‐infrared (NIR) light‐triggered heating induces tumor cell deaths releasing tumor‐derived protein antigens (TDPAs) and adenosine triphosphate (ATP). Thereafter, the released ATP degrades the ZIF‐8 shell to expose the AuNRs, which can promote intratumoral T cell infiltration by capturing TDPAs and transporting them to dendritic cells (DCs). Concurrently, a large amount of αPD‐L1 is released in situ to reinvigorate T cell activity. Mechanistic studies reveal that AZ‐P@P promotes the maturation of DCs and the infiltration of activated T cells, thus eliciting a robust antitumor immunity. It is demonstrated that AZ‐P@P triggered by NIR light can significantly destroy primary tumors and suppress metastasis. This multiple immunoregulatory system provides a promising tool for tumor treatment. [ABSTRACT FROM AUTHOR]