Engineering autologous tumor cell vaccine to locally mobilize antitumor immunity in tumor surgical bed.

Autologous tumor cell-based vaccines (ATVs) are emerging as a transformable approach for personalized immunotherapy, but their therapeutic efficacy remains unsatisfying in patients with cancer. Here, we design a photodynamic therapy (PDT)-motivated ATV (P-ATV) in Fmoc-KCRGDK-phenylboronic acid (FK-PBA) hydrogel, which mobilizes local immune activation to inhibit relapse of postoperative tumors. The FK-PBA targeting overexpressed sialic acid on tumor cells can enable on-demand gelation in residue tumor areas and maintain continuous vaccination in surgical bed. Unlike neoantigen-based vaccine or adoptive cell therapy that takes several months to prepare, P-ATV can be easily manufactured within a few days and efficiently boost neoepitope-specific CD8+ T cells to activate personalized immunotherapy. This simple and powerful approach of engineered ATVs provides an alternative strategy for personalized immunotherapy and is readily transformable to various kinds of cell-based antigens to inhibit the relapse of postoperative tumors.