Highly stable and bioactive yak type I collagen gels for accelerated healing of photoaging skin

Excessive ultraviolet radiation is one of the most common external factors causing skin photoaging, which leads to collagen degradation, wrinkle formation, pigmentation, and is even associated with skin disorders such as seborrheic keratosis and skin tumors. Although various strategies have been developed to treat photoaging skin; however, they suffer from poor stability, risk of allergic reactions, and prolonged recovery periods. In this study, we develop a novel highly stable and bioactive yak type I collagen-based hydrogels dressing to promote the rejuvenation of photoaged skin. The YIC gel demonstrated excellent stability over a six-month period, and maintained the intact triple-helical structure of collagen. It also displayed shear-thinning behavior and notable ductility. In vitro cell experiments confirmed its favorable biocompatibility and bioactivity.Non-invasive Combo evaluations demonstrated the remarkable ability of YIC gel to restore dermal density, elasticity, hydration, and transepidermal water loss to healthy levels, surpassing the efficacy of the commercial product. Histological analysis revealed YIC gel significantly reduced epidermal thickness, promoted the deposition and regeneration of collagen, demonstrating greater efficacy than the commercial product. Antioxidant indicators further highlighted the antioxidant properties of YIC gel, including reduced MDA content, increased SOD activity and GSH content. Immunofluorescence staining suggested that the YIC gel may enhance collagen synthesis through modulation of the TGF-β/Smad signaling pathway. This YIC gel offers valuable insights into its protective effects against skin photoaging and highlights its promising applications in cosmetic formulations.