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

ABSTRACT 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