Water-induced directed self-assembly of matrine-unsaturated fatty acid natural deep eutectic solvent into eutectogel...

Self-assembly of active pharmaceutic ingredient (API)-based small molecules via hydrogen bonds offers a sustainable new approach for constructing functional soft materials. However, construction of gels usually involves complex process and demanding conditions. This work developed a natural deep eutectic solvent (DES) composed of plant-derived alkaloid matrine and unsaturated fatty acids. These systems undergo direct self-assembly in the presence of water without any chemical modification, forming a structurally stable eutectic gel (eutectogel). Spectroscopic analysis and molecular dynamics simulations indicate that the addition of water promotes the redistribution of the hydrogen bond network within the DES, thereby driving the formation of the gel structure. The resulting matrine-unsaturated fatty acid DES and corresponding eutectogels exhibit anti-photoaging capabilities, exerting a protective effect by reducing oxidative stress and inflammatory responses in skin cells. Further mechanism studies show that these systems can regulate the NF-κB signaling pathway, reducing reactive oxygen species (ROS) production and inhibiting the expression of inflammatory factors. This study not only reveals the unique water-induced self-assembly process in API-based DES but also provides a novel strategy for transforming green solvents into functional eutectogels, with potential applications in areas related to oxidative stress and inflammation, such as skin anti-photoaging.