Personalized Vaccination of Tumor‐Derived Antigens and STING Agonists for Specific Cancer Immunotherapy

Abstract Personalized vaccines have shown their promise in cancer immunotherapy, while screening of personalized antigens remains challenging. Herein, a personalized immunotherapy strategy to treat tumors by its own mechanism is reported, which is achieved through the hydrogel‐integrated delivery of tumor‐derived antigens and STING signaling activation. Self‐assembled nanoparticles composed of gallic acid, manganese ions, and mitoxantrone are prepared to induce immunogenic cell death of tumor cells in vitro to release damage‐associated molecular patterns and autologous antigens. Sodium alginate integrated with the released antigens and STING agonists (i.e., MSA‐2) can be instantaneously cross‐linked with endogenous calcium ions in vivo to form hydrogels upon subcutaneous injection. The hydrogels allow for the controlled release of autologous tumor antigens and agonists to activate specific anti‐tumor immune responses via promotion of the maturation of dendritic cells and elicitation of tumor infiltration of cytotoxic T lymphocytes. As a result, the in‐situ formation of hydrogel‐based vaccines can prevent homologous tumor progression and inhibit metastatic tumor growth. This work outlines a straightforward and generalized strategy for personalized vaccination to enhance cancer immunotherapy.