Metabolic click-labeling of interleukin-10 enhances the immunomodulatory potential and wound healing properties of mesenchymal stem cell-derived extracellular nanovesicles

Mesenchymal stem cell-derived extracellular nanovesicles (MSC-NVs) exhibit unique biological properties and tissue-regenerative effects comparable to their parent MSCs. However, despite the robust angiogenic and anti-apoptotic effects of MSC-NVs, their immunomodulatory effect is limited due to insufficient translation of anti-inflammatory cytokines from parent MSCs to isolated NVs. Hence, in this study we suggest the incorporation of interleukin (IL)-10, a key anti-inflammatory mediator in the body's immune system, on the surface of MSC-NVs <i>via</i> bio-orthogonal click chemistry. Metabolically engineered MSCs were serially extruded to generate azido-displaying MSC-NV-N₃, followed by click chemistry-based conjugation of IL-10. Synthesized MSC-NV/IL-10 exhibited superior abilities for cell proliferation and migration of fibroblast and endothelial cells. MSC-NV/IL-10 markedly attenuated the activity of the pro-inflammatory M1 macrophage and promoted the expression of the anti-inflammatory M2 marker. We also demonstrated that MSC-NV/IL-10 induces the phenotypic transition of dendritic cells (DCs) from mature DCs to immune-tolerogenic DCs. Moreover, RNA sequencing revealed that metabolic engineering does not alter the regenerative potential or immunomodulatory functions of MSCs. In animal studies, MSC-NV/IL-10 treated mice exhibited significantly accelerated wound healing, accompanied by resolution of inflammatory responses in injured skin.