METHODS: The harvested stem cells from adipose tissues were isolated, cultured, and then starved. The centrifugation of cell cultures medium yielded the human adipose-derived stem cells conditional medium (HADSCs-CM). Collagen secretion and fibroblast viability of human fibroblasts (Hs68) were measured in the presence of HADSCs-CM. The dermal layer, vascular endothelial growth factor (VEGF), and collagen levels were evaluated on the mice animal models between the treatments with and without HADSCs-CM.
RESULTS: Western blotting, transmission electron microscopy (TEM), and dynamic light scattering (DLS) confirmed that the functional particles in HADSCs-CM were exosomes. When Hs68 fibroblasts were treated with HADSCs-CM, both cell viability and collagen secretion increased in a dose-dependent manner. Following the post-ultraviolet A (post-UVA) exposure, the mice exposed to the HADSCs-CM have decreased dermal thickness and VEGF expression and increased collagen volume compared to the non-HADSCs-CM exposed mice (control group).
CONCLUSION: HADSCs-CM significantly alleviated signs of skin senescence, including reduced dermal thickness, decreased VEGF expression, and enhanced collagen production. Exosomes, identified in the HADSCs-CM, are the functional component of these regenerative effects. This study highlights that the exosomal nanomedicine found in HADSCs-CM could regenerate skin, boost collagen production, improve fibroblast cell viability, and contain functional exosomes.