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Recently, bone marrow endothelial cells (BMECs) were found to play an important role in regulating bone homeostasis. However, few studies utilized BMECs to treat bone metabolic diseases including osteoporosis. Here, we reported bioinspired nanovesicles (BNVs) prepared from human induced pluripotent stem cells-derived endothelial cells under hypoxia culture through an extrusion approach. Abundant membrane C-X-C motif chemokine receptor 4 conferred these BNVs bone-targeting ability and the endothelial homology facilitated the BMEC tropism. Due to their unique endogenous miRNA cargos, these BNVs re-educated BMECs to secret cytokines favoring osteogenesis and anti-inflammation. Owing to the conversion of secretory phenotype, the osteogenic differentiation of bone mesenchymal stem cells was facilitated, and the M1-macrophage-dominant pro-inflammatory microenvironment was ameliorated in osteoporotic bones. Taken together, this study proposed BMEC-targeting nanovesicles treating osteoporosis via converting the skeletal endothelium-associated secretory phenotype.

Cancer is the outcome of the conflict between the host immune system and cancer cells. The crosstalk between immune cells and tumor cells within the tumor microenvironment (TME) influences tumor progression and metastasis. Many studies have clarified the cellular and molecular events that can induce cancer cells to escape immune surveillance, including those involving tumor‐induced myeloid cell‐mediated immunosuppression. Emerging evidence indicates that tumor‐infiltrating myeloid cells (TIMs) accelerate tumor growth and induce angiogenesis, metastasis, and therapy resistance once converted into potent immunosuppressive cells. Here, how tumor infiltrating myeloid cells participate in tumor immune evasion and the prospects of these cells in cancer immunotherapy are discussed.

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