Synthesis of an elastic β-cyclodextrin hydrogel cage by hydroxyethyl cellulose

Current cyclodextrin (CD) hydrogels have disadvantages, including a limited CD content, long reaction time, and complicated chemical reactions. To overcome these, a one-pot reaction was adopted, and a concept of a beta-CD hydrogel cage was proposed. Hydroxyethyl cellulose (HEC) was used as the raw material with the adjustment of the stoichiometric relationship among the cross-linking agent of epichlorohydrin, alkali environment, and beta-CD amount, and an elastic beta-CD hydrogel cage system was established. After the beta-CD was caged, the contents of active beta-CD in hydrogel products reached 74.45 and 69.14 wt % by weight measurement and photometric titration, respectively. Furthermore, compared to the pure HEC hydrogel, the hydrogel mechanical strength improved obviously after the beta-CD was caged, and we obtained a faster water swelling rate at the same time. Finally, a hydrophobic molecule of phenolphthalein (PP) was used to evaluated the activity of caged beta-CD in the hydrogel. In addition, the absorption and release of PP by an elastic beta-CD hydrogel cage at certain time intervals were also studied. The results demonstrate that the beta-CD hydrogel cage was used as a functional molecule carrier to quickly absorb and sustain the release of PP. (C) 2016 Wiley Periodicals, Inc.