Chitosan‐based Polyelectrolyte Complexes Soluble in Enzyme‐friendly pH Range

By studying chitosan interactions with poly(styrene sulfonate) anions, a procedure that yields chitosan-based non-stoichiometric polyelectrolyte complexes soluble in neutral media has been developed. The elaborated strategy of the complex formation depended on the peculiar order of mixing the polyelectrolyte solutions, which served as a remedy for kinetic hindrances. The kinetic restrictions inevitably occurred on direct mixing of the components in slightly acidic and neutral media, due to the significant contribution of hydrogen bonds in stabilization of the intermediate insoluble products. The approach developed opens up a new avenue of attack on the problem of preparing water soluble biocompatible and biodegradable chitosan complexes that are suitable for use at physiological pH and ionic strength.