Hyaluronic acid/ε-polylysine hydrogel enriched with Saussurea involucrata polysaccharide for improved skin dryness induced by ultraviolet radiation

Ultraviolet B (UVB) radiation exposure is a major contributor to skin photoaging, ultimately resulting in dryness. Conventional treatments for this condition frequently exhibit limited efficacy due to poor skin penetration and are associated with significant side effects. Saussurea involucrate polysaccharide (SIP) has been shown to alleviate photoaging-induced dry skin; however, its effectiveness is limited due to low drug utilization and the need for frequent dosing. In this study, we developed hyaluronic acid (HA) and ε-polylysine (ε-PLL) hydrogels designed to enhance skin hydration and enable sustained drug release. The optimal formulation, designated A5E3, contained 5 % HA plus 3 % ε-PLL. The sustained release of SIP from A5E3 demonstrated superior therapeutic effects in a mouse model of skin photoaging, including reduced inflammation and apoptosis, as well as enhanced keratinocyte differentiation and lipid production. The A5E3 hydrogel not only enhanced the drug utilization of SIP but also provided a sustained moisturizing environment, promoting faster skin repair. These findings support the development of skincare products with superior moisturizing and reparative properties, underscoring the potential of hydrogels as effective carriers for treating UVB-induced skin dryness and damage.