Polysaccharide Gels Based on Chitosan and Modified Starch: Structural Characterization and Linear Viscoelastic Behavior

We investigated the properties of polymeric systems formed by cross-linking chitosan with modified starch (oxidized maltodextrin). Such a macromolecular cross-linker proved to be efficient to react with chitosan with potentially minimal toxicity. The structural characterization of modified starch alone and of the two-polysaccharide reactive systems was performed using H-1 NMR and FTIR. The rheological behaviors of all systems, from solutions to gels, were also characterized. Depending on experimental parameters, such as chitosan concentration, cross-linking pH, degree of oxidation of starch, and molar ratio of reactive groups, different kinds of systems ranging from pure viscoelastic solutions to stiff hydrogels were formed. These versatile systems could be used in biomedical applications because of the good biocompatibility of their constituents.