Nanoliposome-embedded alginate/κ-carrageenan double-network composite beads: Characterization, molecular...

This study developed nanoliposome-integrated composite beads for the encapsulation and controlled release delivery of quercetin (Q) by incorporating various concentrations of quercetin-loaded nanoliposomes (QNLs, 96.9 nm diameter) into a sodium alginate/κ-carrageenan mixture. The microstructural, stability, textural, swelling, and gastrointestinal (GI) release properties of wet and dry beads were analyzed. QNL-loaded beads achieved excellent Q encapsulation efficiency (>98 %). They exhibited a smooth, even, and less porous microstructure, with a bead size of 2.42-2.59 mm (wet) and 1.01-1.08 mm (dry). Thermally, QNL-beads were more stable, losing 32 % mass at 265-275 °C, whereas the control (non-nanoliposomal) bead lost the same mass at 250 °C. Drying significantly reduced textural quality and increased the swelling index. Consequently, wet beads displayed a sustained release of Q throughout GI digestion, with QNL-beads having better controlled release capabilities than control beads. Despite a comparable controlled-release pattern observed at the gastric phase, the QNL-integrated dried beads exhibited expedited Q release rates in the intestinal fluid. The wet and dried beads showed Fickian diffusion and anomalous transport mechanisms, respectively, demonstrating that molecular diffusion influences Q release kinetics in wet beads and diffusion and polymer relaxation in dried beads. Overall, embedding nanoliposomes within the composite hydrogel matrix provides a dual-protection strategy, significantly enhancing Q stability and enabling controlled, targeted delivery. This approach holds strong translational potential for functional foods and precision pharmaceuticals.