Preparation and drug release behavior study of intelligent pH-Responsive sodium alginate/κ-carrageenan polysaccharide-based hydrogels

Fucoxanthin (FX), a natural carotenoid sourced from algae, is renowned for its strong antioxidant, anti-inflammatory, and anticancer effects, positioning it as a promising candidate for applications in functional foods and pharmaceuticals. Despite its potential, FX suffers from low oral bioavailability and is prone to degradation during digestion, hindering its effective absorption in the colon. In this study, κ-carrageenan-sodium alginate (Car-SAA) hydrogel beads were employed as an encapsulation system to investigate their pH-responsive drug release behavior and their influence on FX's oral bioavailability. The results showed that the hydrogel beads exhibited excellent mechanical properties in simulated colonic fluid (SCF), intestinal fluid (SIF), and gastric fluid (SGF). FX was gradually released in SGF and SIF, while a rapid release was observed in SCF, with a cumulative release of 74.38 ± 2.00% after 72 h for Car-SAA2.0-FX. This behavior was likely due to the swelling properties of the hydrogel, and the release kinetics were consistent with the Korsmeyer-Peppas model. Moreover, in vitro cytotoxicity assays showed that FX-loaded Car-SAA2.0 hydrogel beads had no significant impact on HaCaT cells but exhibited significant inhibitory effects on cancer cells. These findings indicated that the formulation holds promise as a colon-targeted delivery system, paving the way for future innovations in functional foods and pharmaceutical formulations.