Abstract

Extracellular vesicles (EVs) isolated from mesenchymal stem cells hold tremendous potential in regenerative medicine. Deer antler stem cells (ASC), well-known for their distinctive regenerative ability, secrete ASC-EVs that are highly concentrated with bioactive factors that could improve skin regeneration and delay skin aging. The exact potential of ASC-EVs in relieving oxidative-stress-triggered fibroblast aging and burn injuries has yet to be explored. ASC-EVs were purified from ASCs and identified by morphological evaluation, size analysis, and surface protein expression. The biological function of ASC-EVs was examined using H2O2-stimulated senescent human fibroblasts, assessing migration assays, β-Galactosidase staining, and gene expression for senescence-associated markers (p16, p21, p53) and fibroblast abilities (Coll1, Coll3). Additionally, a rat burn model was induced by creating standardized dorsal skin burns, followed by ASC-EV or PBS treatments. Wound closure, morphological analysis (HE stain), and gene expression for cytokines (IL-10, TNF-α) were examined at day 16. ASC-EVs significantly attenuated the expression of both fibroblast senescence and stimulated Col1 and Col3. Moreover, they also stimulated the migration of fibroblasts. Besides, EVs-treated rats significantly restored skin structure and the retention of adnexal structures when compared to the Sham group in the burn model. Molecular studies also identified a significant increase (p < 0.05) in IL-10 expression and a decline in TNF-α expression (p < 0.05) in ASC-EVs-treated wounds. ASC-EVs possessed dual therapeutic properties in that they suppressed the senescence of fibroblasts in vitro and supported the healing of burns in vivo by both structural regeneration and regulation of inflammation. The discovery of ASC-EVs indicated that a novel, cell-free therapy for skin rejuvenation and burn treatment could be developed.

Key words: Anti-aging, Antler stem cells, Human fibroblast, Oxidative stress, Secretome, Senescence, Wound healing