A Self‐Cascading Catalytic Therapy and Antigen Capture Scaffold‐Mediated T Cells Augments for Postoperative Brain Immunotherapy

Abstract The recruitment of T lymphocytes holds great potential for suppressing the most aggressive glioblastoma (GBM) recurrence with immunotherapy. However, the phenomenon of immune privilege and the generally low immunogenicity of vaccines often reduce the presence of lymphocytes within brain tumors, especially in brain tumor recurrence clusters. In this study, an implantable self‐cascading catalytic therapy and antigen capture scaffold (CAS) that can boost catalytic therapy efficiency at post‐surgery brain tumor and capture the antigens via urethane‐polyethylene glycol‐polypropylene glycol (PU‐EO‐PO) segments are developed for postoperative brain immunotherapy. The CAS consists of 3D‐printed elastomers modified with iron (Fe 2+ ) metal‐organic frameworks (MOFs, MIL88) and acts as a programmed peroxide mimic in cancer cells to initiate the Fenton reaction and sustain ROS production. With the assistance of chloroquine (CQ), autophagy is inhibited through lysosome deacidification, which interrupts the self‐defense mechanism, further enhances cytotoxicity, and releases antigens. Then, CAS containing PU‐EO‐PO groups acts as an antigen depot to detain autologous tumor‐associated antigens to dendritic cells maturation and T cell augments for sustained immune stimulation. CAS enhanced the immune response to postoperative brain tumors and improved survival through brain immunotherapy.