Abstract
Exposure to ultraviolet (UV) radiation compromises both the aesthetic and functional properties of the skin, accelerates aging, increases the risk of skin cancer, and significantly impairs quality of life. Exosomes derived from human umbilical cord mesenchymal stem cells (hUMSC-Exo) and natural compounds such as epigallocatechin gallate (EGCG) show great therapeutic potential for UV-induced skin damage. However, their efficacy is often limited by poor stability, low bioavailability, and inefficient skin penetration. In this study, we show that hUMSC-Exo and EGCG act synergistically to reduce oxidative stress and exert potent anti-inflammatory effects. By incorporating these agents into a microneedle-based delivery system, we achieved efficient transdermal co-delivery, which significantly enhanced the repair of UV-induced skin injury. The treatment markedly attenuated inflammatory responses, reduced DNA damage, and promoted tissue regeneration. These findings suggest that hUMSC-Exo/EGCG-loaded microneedles provide a simple yet effective strategy for treating UV-induced skin damage and aging, with potential applicability to a broader range of inflammatory skin conditions.