Autocatalytic Ceria Nanoparticle-Embedded Tilapia Collagen Hydrogels as Enhanced Antioxidative and Long-Lasting Dermal Fillers for Photoaged Skin.

Excessive reactive oxygen species (ROS) generated by ultraviolet (UV) irradiation significantly contribute to photoaging by increasing the level of matrix metalloproteinases (MMPs), accelerating collagen degradation. Commercial dermal fillers offer temporary wrinkle reduction via volume enhancement. In this study, we propose tilapia-derived collagen hydrogels embedded with ceria nanoparticles (Ce@Col gels) as long-lasting dermal fillers for UVB-induced photoaging. Ceria nanoparticles (CeNPs) significantly enhance the stability of the collagen matrix against enzymatic degradation. These gels exhibit mechanical stability and injectability comparable to those of commercial alternatives. Additionally, CeNPs effectively eliminate ROS to suppress MMP production, curbing both collagen degradation and inflammatory responses. In a UVB-induced photoaging mouse model, the Ce@Col gels significantly reduced the level of oxidative stress in the skin, decreased the number of wrinkles, reduced epidermal thickness, and decreased levels of aging-related biomarkers while increasing the level of collagen deposition. These antiaging effects persisted for seven months post-injection, highlighting Ce@Col gels as a promising approach for prolonged collagen regeneration and sustained anti-inflammatory benefits in photoaged skin.