Hydrophobic Derivatization of Sodium Alginate for Use in Fucoxanthin Delivery

Abstract

In this study, sodium alginate was modified with octyl chloride (C8) via an esterification reaction to impart amphiphilic self-assembly property and loading of fucoxanthin via sonication. The hydration diameter and critical aggregation concentration of the micellar-like aggregates gradually decreased with the increasing degree of substitution. The encapsulation efficiency and loading capacity 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.

Keywords: Sodium alginate, Hydrophobic modification, Targeted delivery