Synthesis and characterization of functional multilayer capsules based on chemically modified polysaccharides

Polyelectrolyte multilayer microcapsules are made by layer-by-layer (LbL) assembly of oppositely charged polyelectrolytes onto sacrificial colloidal particles, followed by core removal. In this paper, we prepared contact killing polyelectrolyte microcapsules based solely on polysaccharides. To this end, water-soluble quaternized chitosan (QCHI) with varying degree of substitution (DS) and hyaluronic acid (HA) were assembled into thin films. The quaternary ammonium groups were selectively grafted on the primary amine group of chitosan based on its reaction with glycidyltrimethylammonium chloride (GTMAC) under homogeneous aqueous acidic conditions. We found that the morphology of the capsules was closely dependent on the DS of the quaternized chitosan derivatives, suggesting differences in their complexation with HA. The DS was also a key parameter to control the antibacterial activity of QCHI against Escherichia Coli (E. coli). Thus, capsules containing the QCHI derivative with the highest DS were shown to be the most efficient to kill E. coli while te l-0 06 21 20 8, v er si on 1 9 Se p 20 11