Engineered Iron-Based nanoplatform amplifies repolarization of M2-Like Tumor-Associated Macrophages for enhanced cancer immunotherapy

Resetting M2-like tumor-associated macrophages (TAMs) to antitumor M1 phenotype is a promising strategy in cancer immunotherapy. Although iron-based nanoparticles exhibit the potential of M2-to-M1 macrophage repolarization, the efficient M2-like TAM targeting and the subsequent intracellular iron retention remains a big challenge. Here, M2 macrophage-targeting peptide-conjugated iron-based metal–organic frameworks are developed to load diclofenac ([email protected]) for enhanced cancer immunotherapy. [email protected] efficiently targets M2-like TAMs and decreases the efflux by hepcidin/ferroportin signaling pathway, enabling enhanced intracellular accumulation for improved M2-to-M1 macrophage repolarization. [email protected] M2-like TAMs efficiently kill and phagocytose tumor cells, and importantly remodel tumor immune microenvironment to generate long-term antitumor immune memory, eliciting strong anticancer efficacy with tumor recurrence inhibition. Our results support [email protected] as a potential drug for cancer immunotherapy.