Novel multifunctional composite cryogel with high-performance and rapid fat-lowering efficacy via the synergy of fat digestion blockage and synthesis inhibition.

Excessive dietary fat intake poses considerable health risks. Developing biomaterials with fat adsorption and digestion intervention properties may satisfy consumer preferences for fat taste while enhancing anti-obesity efficacy. However, this strategy has remained largely unrealized. Cryogels, known for exceptional wettability and porous structure, are not employed as fat-blocking biomaterials with dual functionality. Herein, a novel curcumin (Cur)-releasing hydrophobic oral composite cryogel with excellent fat ingestion inhibition was fabricated using cellulose nanofiber (CNF) and carrageenan (Car). By optimizing the preparation process, the microstructure, porosity, and adsorption properties were analyzed to improve performance and functionality. Subsequently, the lipophilic performance and fat-lowering effect of the cryogel were further investigated through simulated gastrointestinal digestion and high-fat diet models. The proposed oral cryogels, with 91.10-98.70 % porosity and 145° hydrophobic angle, displayed favorable porous structure and fat/oil absorption capacity. Incorporation of Car-CNF-Cur cryogel reduced stimulated fat hydrolysis by 23.4 %. Additionally, supplementation with Car-CNF-Cur cryogels in high-fat diet significantly lowered body weight and fat synthetase expression in mice after short-term ingestion. This treatment also increased fecal fat content by 29.45 %, suppressed inflammation and lipopolysaccharide without toxicity, along with modulated gut microbiota composition, thereby interfering with fat digestion. Collectively, these findings highlight the potential of Car-CNF-Cur cryogels as a promising oral fat-lowering biomaterial for obesity management.