Hydrophobic derivatization of sodium alginate for use in fucoxanthin delivery

Abstract

The present study successfully devised an innovative pH-sensitive system for encapsulating fucoxanthin, which effectively shielded RAW 264.7 cells from H2O2-induced damage. The formulation requires modification of sodium alginate with octanoyl chloride (C8) via esterification to provide amphiphilic self-assembly capacity of the system and loading of fucoxanthin via sonication. The hydration diameter (193.9–167.9 nm) and critical aggregation concentration of the micellar-like aggregates (1.4–0.5 mg/mL) gradually decreased with the increasing degree of substitution (1.54 %–60.20 %). The encapsulation efficiency (46.11 %–88.54 %) and loading capacity (4.61 %–8.85 %) showed a positive correlation with the increasing degree of substitution. The TEM confirmed complete fucoxanthin encapsulation in micellar-like aggregates, forming smooth-surfaced spherical particles. In vitro simulated digestion assays demonstrated that micellar-like aggregates effectively shielded fucoxanthin from premature gastric release, while significantly improving its release efficiency during the intestinal phase. Fucoxanthin-loaded micellar-like aggregates endocytosed by RAW 264.7 cells alleviated cellular oxidative stress damage by reducing ROS levels. The study demonstrates the potential of self-assembled sodium alginate nanoparticles as a novel carrier for efficient delivery of hydrophobic substances, thereby establishing an innovative formulation for alleviating oxidative stress