Proximity Estimation and Quantification of Ionizing Radiation-induced DNA Lesions in Aqueous Media using Fluorescence Spectroscopy.

INTRODUCTION

Research has unveiled the remarkable properties of extracellular vesicles derived from mesenchymal stromal cells (MSCs), particularly in promoting wound healing, aiding re-epithelialization, revitalizing aging skin, and inhibiting hyperpigmentation. However, investigations into the potential of small extracellular vesicles from umbilical cord-derived MSCs (UC-MSC-sEVs) in reducing scarring and preventing hyperpigmentation remain limited. Therefore, this study aims to evaluate the impact of UC-MSC-sEVs on the synthesis of the skin's extracellular matrix (ECM) and pigmentation using in vitro models.

METHODS

The study investigated the impact of characterized UC-MSC-sEVs on various aspects including the proliferation, migration, antioxidant activity, and ECM gene expression of human dermal fibroblasts (HDF). Additionally, the effects of UC-MSC-sEVs on the proliferation, melanin content, and tyrosinase (TYR) activity of human melanoma cells (MNT-1) were examined. Furthermore, ex vivo models were employed to evaluate the skin permeation of PKH26-labelled UC-MSC-sEVs.

RESULTS

The findings indicated that a high concentration of UC-MSC-sEVs positively influenced the proliferation of HDF. However, no changes in cell migration rate were observed. While the expressions of collagen type 1 and type 3 remained unaffected by UC-MSC-sEVs treatment, there were dose-dependent increases in the gene expressions of fibronectin, matrix metallopeptidase (MMP) 1, and MMP 3. Furthermore, UC-MSC-sEVs treatment did not impact the antioxidative superoxide dismutase (SOD) expression in HDF. Although UC-MSC-sEVs did not alter the proliferation of MNT-1 cells, it did result in a dose-dependent reduction in melanin synthesis without affecting TYR activity. However, when it was applied topically, UC-MSC-sEVs failed to penetrate the skin barrier and remained localized within the stratum corneum layer even after 18 hours.

CONCLUSION

These results highlight the potential of UC-MSC-sEVs in stimulating HDF proliferation, regulating ECM synthesis, and reducing melanin production. This demonstrates the promising application of UC-MSC-sEVs in medical aesthetics for benefits such as scar reduction, skin rejuvenation, and skin lightening.