Self-assembly behavior and conformation of amphiphilic hemicellulose-graft-fatty acid micelles

In this work, a series of amphiphilic hemicellulose-based grafting polymers are synthesized by homogeneous esterification with various hydrophobic chain fatty acids. With the flexible chain conformation of hemicelluloses, the hemicellulose-graft-fatty acid is self-assembled into hard sphere micelles in aqueous solution through hydrophobic interactions. The resultant micelles show apparent hydrodynamic radius (R_h) varying in the range of 34-57 nm and radius of gyration (R_g) varying from 30 to 44 nm. Moreover, the R_h, R_g, zeta potential and critical micelle concentration (CMC) of the micelles gradually decreases with the increasing hydrophobic chain length. The aggregation number of micelles can be tuned by varying alkyl chain lengths. Taking curcumin (Cur) as a model drug, the hemicellulose micelles were investigated as drug carriers, which exhibit a chain length-controlled drug release behavior. Taken together, structure and property tunable hemicellulose-based micelles were obtained, and showed potential of application in pharmaceutical, food, and cosmetics fields.