Water-soluble poly(ethylene glycol) methyl ether-grafted chitosan/alginate polyelectrolyte complex hydrogels.

ABSTRACT

This study aimed to fabricate polyelectrolyte complexes from water-soluble poly(ethylene glycol) methyl ether-grafted chitosan (mPEG-g-CTS) and alginate (ALG) in the absence of acetic acid. The complexes formed fibrous network macrogels when mPEG-g-CTS with short mPEG chains (mPEG750-g-CTS and mPEG2000-g-CTS) and mPEG-g-CTSALG weight ratios in the range from 10.14 to 11 were used. The macrogels at a weight ratio of mPEG-g-CTSALG of 11 possessed the highest elasticity with electrophoretic mobility close to 0 m2·V-1·s-1. Water uptake of the sponge-like lyophilized macrogels decreased with increasing ALG content, mPEG chain length, and degree of substitution of mPEG-g-CTS. In contrast, the polyelectrolyte complexes prepared using long mPEG chains of mPEG-g-CTS (mPEG5000-g-CTS) formed spherical nanoparticles (70-90 nm) and showed highly negative electrophoretic mobility (< -3.20 × 108 m2·V-1·s-1). The obtained mPEG-g-CTS/ALG polyelectrolyte complex hydrogels and nanoparticles have the potential to be applied as carriers for functional food additives, drugs, and bioactive compounds.