A Stable and Local H₂ Nanogenerator for Antifading Responses

Persistent inflammation effects existed in the senescence microenvironment, and hydrogen (H₂) was an antioxidant stress agent and could solve the aging and inflammation. In view of the issue of low solubility of H₂ and conversion efficiency of traditional hydrogen therapy, an in-site hydrogen production system (HPS) was designed by using liposome as a compartment, emodin as a photosensitizer, l-ascorbic acid-2-phosphate trisodium salt (AAP) as hydrogen sources, and Au NPs as photocatalysts. Different from the commonly used chlorophyll A, emodin with strong absorption in the wide range of 200-500 nm could absorb more photons to form electrons for the participation of H₂ generation. Emodin- and AAP-embedded HPS largely increased stability at 50 °C for 28 days. HPS facilitated the decrease of inflammatory factors of TNF-α, IL-6, and ROS in RAW264.7 cells, as well as the elimination of senescence-associated β-galactosidase, realizing convenient and efficient antifading responses. But strikingly, the constructed HPS can penetrate the pig skin in transdermal experiments and showed huge prospects for the application of antifading cosmetics.