Reshaping Intratumoral Mononuclear Phagocytes with Antibody‐Opsonized Immunometabolic Nanoparticles

Abstract Mononuclear phagocytes (MPs) are vital components of host immune defenses against cancer. However, tumor‐infiltrating MPs often present tolerogenic and pro‐tumorigenic phenotypes via metabolic switching triggered by excessive lipid accumulation in solid tumors. Inspired by viral infection‐mediated MP modulation, here enveloped immunometabolic nanoparticles (immeNPs) are designed to co‐deliver a viral RNA analog and a fatty acid oxidation regulator for synergistic reshaping of intratumoral MPs. These immeNPs are camouflaged with cancer cell membranes for tumor homing and opsonized with anti‐CD163 antibodies for specific MP recognition and uptake. It is found that internalized immeNPs coordinate lipid metabolic reprogramming with innate immune stimulation, inducing M2‐to‐M1 macrophage repolarization and tolerogenic‐to‐immunogenic dendritic cell differentiation for cytotoxic T cell infiltration. The authors further demonstrate that the use of immeNPs confers susceptibility to anti‐PD‐1 therapy in immune checkpoint blockade‐resistant breast and ovarian tumors, and thereby provide a promising strategy to expand the potential of conventional immunotherapy.