Fibroblast-Derived Extracellular Vesicles Ameliorate the Skin Injury Microenvironment to Promote Wound Healing.

Fibroblasts are pivotal cellular components in cutaneous wound healing and are regarded as promising therapeutic candidates. However, their functional heterogeneity within tissue microenvironments significantly limits their clinical application. In contrast, whether fibroblast-derived extracellular vesicles (EVs) can overcome fibroblast heterogeneity while retaining the bioactivity and regenerative potential of homeostatic fibroblasts remains unclear. In this study, we systematically analyzed and compared the therapeutic potential and functional advantages of human dermal fibroblast-derived EVs (hDF-EVs) in promoting cutaneous wound healing. Our findings highlight the translational potential of fibroblast-derived EVs as a novel strategy to improve clinical outcomes for skin injuries. hDF-EVs were internalized by fibroblasts and keratinocytes at the wound margins, thereby attenuating early inflammatory responses and accelerating tissue repair following dermal excisional injuries. hDF-EVs significantly enhanced the proliferation and migration of both fibroblasts and keratinocytes in a coculture system. Transcriptomic analysis revealed that hDF-EVs upregulated genes involved in cell proliferation and cytokine regulation. Integrated miRNA profiling revealed a subset of hDF-EVs-enriched miRNAs that mechanistically orchestrate fibroblast activation through coordinated MAPK, Wnt, and Ras signaling axis engagement, consequently reprogramming inflammatory mediator secretion dynamics in wound microenvironments. Furthermore, cytokine array analysis demonstrated that hDF-EVs enhanced the expression of various cytokines, including Amphiregulin, GCSF, IL-7, and IL-2, while activating Ras, Rap1, PI3K-Akt, and MAPK signaling pathways during the early stage of wound healing. Collectively, hDF-EVs promote wound healing by modulating early growth factor dynamics and enhancing fibroblast-keratinocyte crosstalk, presenting a novel cell-free strategy for skin regeneration.