Peptide Hydrogels for Postoperative Tumor Therapy: Enhancing Immune Modulation and Local Drug Delivery

Postoperative tumor cavities provide a transient but targetable immune niche where local biomaterials can suppress residual disease and complement systemic therapy. Self-assembling peptidic hydrogels are uniquely suited for this setting because their molecular programmability, supramolecular order, and tissue-conforming mechanics enable both precision drug delivery and immune modulation. In this review, we organize recent advances into three emerging strategies: (i) immunoactive carriers that remain immunologically inert while delivering innate agonists, nucleic acids, or antibodies with spatial and temporal precision; (ii) intrinsically immunomodulatory matrices whose chirality, supramolecular order, and mechanics regulate dendritic-cell activation, macrophage polarization, and memory formation; and (iii) drug-as-hydrogelator formats that integrate cytotoxic debulking and myeloid reprogramming within a single filament network. We highlight design elements such as sequence-encoded motifs, stimulus-responsive linkers, chemokine programming, and logic-gated release systems, and we discuss translational considerations including cavity geometry, surgical workflow, and safety liabilities. Together, these strategies reframe the resection cavity as a programmable immune interface rather than a passive drug reservoir, pointing toward material-centric frameworks that could transform postoperative oncology. This article is categorized under: Biology-Inspired Nanomaterials > Peptide-Based Structures Therapeutic Approaches and Drug Discovery > Emerging Technologies.