Inhibition of Immunosuppressive Tumors by Polymer‐Assisted Inductions of Immunogenic Cell Death and Multivalent PD‐L1 Crosslinking

surface receptor crosslinking, and produces prolonged elimination of PD-L1 rather than the transient blocking afforded by standard anti-PD-L1 antibodies. Together, these findings established the polymer-facilitated tumor targeting of immunogenic drugs and surface crosslinking of PD-L1 as a potential new therapeutic strategy to propagate a long-term antitumor immunity, which might broaden the application of immunotherapy to immunosuppressive cancers.