Multifunctional Neutrophil Nanovesicles Induce Remodeling of Tumor Immune Microenvironment and Synergistic Multimodal Tumor Therapy

ABSTRACT Extracellular vesicles (EVs) from immune cells represent a novel drug delivery system with inherent anti‐tumor properties. To remodel the immunosuppressive tumor microenvironment and mediate multimodal therapy, we produced neutrophil nanovesicles at high yield and loaded them with drug (doxorubicin, DOX), near‐infrared region II fluorescent dye (FD1080), and PD‐1 inhibitor (TFA) through a simple extrusion method and further modified them with DSPE‐PEG2000‐cRGD to enhance their tumor‐targeting ability. The RGD‐NNV@FD1080&DOX/TFA exhibited excellent photothermal effect and efficiently suppressed tumor progression in mouse xenograft tumor, PDX, and lung metastasis models. Upon laser irradiation, the RGD‐NNV@FD1080&DOX/TFA elicited the activation of anti‐tumor immunity with increased infiltration of mature dendritic cells (DCs), CD8 + T cells, and decreased infiltration of regulatory T cells (Tregs) in tumors. Single‐cell RNA sequencing revealed that the combination therapy increased the subtype of cytotoxic and memory T cells while decreasing that of exhausted T cells, and re‐polarized M2 TAMs and N2 TANs. The re‐challenge model further confirmed that RGD‐NNV@FD1080&DOX/TFA exerted effective long‐term immune memory in mouse models and displayed excellent biosafety in vivo. Overall, we designed a simple and potentially clinically applicable nanovesicle‐based nanomedicine delivery system that exhibits a highly efficient anti‐tumor effect by remodeling the tumor immune microenvironment and activating anti‐tumor immunity.