In Situ Peptide Self‐Assembly Augments Antibody Recruitment for Tumor Immunotherapy

In innate immune regulation-based therapy, the degree of killing by innate immunity depends on the number of antibodies binding on the tumor cells. It is well known that antibodies can only bind to tumor cells by interacting with specific receptors. However, there is little receptor expression on the surface of tumor cells, so it becomes a challenge to recruit a sufficiently large number of antibodies to activate innate immunity. Here, we developed a peptide self-assembly antibody recruitment strategy (SARS), which uses intermolecular non-covalent forces of assembled peptides, resulting in a large number of peptide molecules on the tumor surface. The assembly exhibits a fivefold increase in antibody recruitment capacity compared to the monomer, resulting in a fivefold enhancement of the final immune-mediated killing effect. This strategy reduces the dependence on cell surface antigens, demonstrating that self-assembled antibody-recruiting molecules have strong antibody-recruiting as well as tumor cell-killing abilities in vitro and in vivo. These findings emphasize the potential of self-assembled peptides as a promising novel antibody-recruiting nanomaterial for cancer immunotherapy.