Goat Milk-Derived Extracellular Vesicles Attenuate Hydrogen Peroxide-Treated Cell Damage in Human Skin Fibroblasts

Abstract

Oxidative damage drives skin aging, yet the poor skin permeability of antioxidants often limits their efficacy. Extracellular vesicles (EVs) have lipid bilayer structure and nanoscale size, emerge as promising intercellular communication mediators. Milk-derived EVs offer distinct advantages over plant or animal sources, including high yield and minimal preprocessing requirements. Despite goat milk is widely utilized in whitening and anti-aging cosmetics, the anti-aging mechanisms of goat milk-derived EVs (GMEVs) remain underexplored. This study investigates GMEVs’ protective effects against oxidative stress in human skin fibroblasts cells (HSFs cells). Isolated through ultracentrifugation and sucrose density gradients, GMEVs-1 (174.3 ± 1 nm) and GMEVs-2 (213.8 ± 3 nm) were characterized by transmission electron microscope, nanoparticle tracking analysis, and proteomic analysis (identifying 2301 proteins, 58 proteins were unique to GMEVs-1, and 144 proteins were unique to GMEVs-2). Confocal imaging confirmed DiO-labeled GMEVs internalization in HSFs cells, which reduced H₂O₂ -induced β-galactosidase activity and reactive oxygen species (ROS) levels while enhancing migration rates (p < 0.05). Mechanistically, GMEVs-1 and GMEVs-2 attenuated hypertrophic scarring through TGF-β1/SMAD pathway influence collagen I synthesis (p < 0.05), MMP-1/MMP-3 inhibition with TIMP-1 upregulation (p < 0.05), and suppression of caspase-dependent apoptosis, as verified by multi-method analyses (ELISA, immunofluorescence, Western blot). Fluorescent tracking in BALB/c-nu mice demonstrated significant epidermal retention without histopathological toxicity or serum biomarker alterations. Both GMEVs-1 and GMEVs-2 exhibited anti-oxidative stress effects; GMEVs-2 demonstrated superior efficacy at a lower protein concentration. These findings position GMEVs (GMEVs-1 and GMEVs-2) as promising nanoscale candidates for developing enhanced anti-aging skincare therapeutics with improved epidermal bioavailability.