Hydrogel Composed of Chitosan and Cyclodextrin and Evaluation of its Antioxidant Activity

The hydrogels composed of chitosan and carboxylmethyl-β-cyclodextrin (CMCD) were prepared to enhance and sustain the antioxidant activities. The carboxylic groups of CMCD were directly grafted and cross-linked on the amino groups of chitosan. The swelling rate decreased with increasing the CMCD contents in the hydrogel and the swelling ratio of CMCD-grafted chitosan hydrogels was improved due to breaking the crystallinity of chitosan caused by introducing the bulky group such as cyclodextrin. The scavenging activity of the tested hydrogels increased with CMCD contents, because antioxidants entrapped in the CMCD were potent free radical terminators.