EGF-loaded, bioactive-rich Panax notoginseng-derived nanovesicles accelerate skin wound healing

Wound healing is a complex physiological process involving homeostasis, inflammation, proliferation, migration and tissue remodeling. Impaired keratinocyte migration across the wound bed is a key determinant of non-healing wounds. In this context, plant-derived nanovesicles (PDNVs) have emerged as promising therapeutic agents for wound healing due to their high yield, intrinsic biocompatibility, the ability to traverse biological barriers, and an intrinsic molecular cargo (lipids, proteins, nucleic acids, and phytochemicals) that can exert multitarget effects. In this study, we screened a panel of six PDNVs and found Panax notoginseng-derived PDNVs (PNVs) displayed superior cell proliferation-promoting activity. To further amplify the bioactivity of PNVs, we actively loaded epidermal growth factor (EGF) onto PNVs (EGF@PNVs). By employing LC-MS and miRNA sequencing, we identified abundant small-molecule compounds (e.g., ginsenoside Rb1, Rg1) and miRNAs (e.g., miRNA 159) in PNVs. In vitro experiments demonstrated that PNVs and EGF@PNVs significantly enhanced the proliferation and migration of human keratinocytes (HACAT) as well as the repair of skin mechanical trauma. Moreover, they not only directly accelerated the proliferation and migration of L929 mouse fibroblast cells (L929 cells) but also orchestrated the secretion of TNF-α by mouse mononuclear macrophages (RAW264.7 cells). This cytokine subsequently induced the fibroblast activation or phenotype modulation in L929 cells, further augmenting their proliferative and migratory potential. In a mouse skin injury model both formulations accelerated wound closure and exerted immunomodulatory effects, with EGF@PNVs consistently outperforming PNVs. Collectively, our findings introduce EGF@PNVs as a natural, cost-effective, topical alternative to conventional biologics for wound management.