Protecting Against Postsurgery Oral Cancer Recurrence with an Implantable Hydrogel Vaccine for In Situ Photoimmunotherapy

nanoparticles, are directly released into the resected tumor bed. This approach induces apoptosis of residual OSCC cells through sequential near-infrared irradiation, promoting calcium interference therapy (CIT). The hydrogel further stimulates immunogenic cell death (ICD), facilitating the polarization of tumor-associated macrophages from the M2 to the M1 phenotype. This facilitates phagocytosis, dendritic cell activation, robust antigen presentation, and cytotoxic T lymphocyte-mediated cytotoxicity. In murine OSCC models, the in situ vaccine effectively prevents local recurrence, inhibits orthotopic OSCC growth and pulmonary metastases, and provides long-term protective immunity against tumor rechalle nge. These findings support postoperative in situ vaccination with a biocompatible hydrogel implant as a promising strategy to minimize residual tumor burden and reduce recurrence risk after OSCC resection.