Effects of oxidation degree on the physicochemical properties of xanthan gum hydrogels containing N,O-carboxymethyl chitosan

Most xanthan gum-based hydrogels are crosslinked by physical methods, but they typically have inadequate mechanical strength and low thermal, pH, and salt stability. To improve the physicochemical properties of XG-based hydrogels, this study applied periodate oxidation of XG to produce ring-opened products with dialdehyde groups for forming chemically crosslinked hydrogels. The research investigated the effects of oxidized xanthan gum (OXG) at different degrees on the properties of its hydrogels with N,O-carboxymethyl chitosan (NOCC), a water-soluble chitosan derivative. Results show that the rigidity and brittleness of NOCC/OXG hydrogels were enhanced with the increased oxidation of XG. Additionally, the swelling ratio of NOCC/OXG hydrogels was increased by 3.5 times and the degradation rate was reduced by 1.5 times. These hydrogels are promising biomaterials for drug delivery, cell therapy, or tissue regeneration applications.