Preparation and study of cellulose-based ZnO NPs@HEC/C-β-CD/Menthol hydrogel as wound dressing

A cellulose-based hydrogel with synergistic therapeutic effect was prepared by a one-pot method. The hydrogel had hydroxyethyl cellulose (HEC) as a framework and epichlorohydrin (EPI) as a cross-linking agent. Cationic-β-cyclodextrin (C-β-CD) was homogeneously embedded in the grid of the cross-linked structure. Zinc oxide nanoparticles (ZnO NPs) and menthol were used to provide analgesic and bactericidal effects. Menthol was uniformly loaded onto the hydrogel matrix by the addition of C-β-CD and increased the solubility of menthol in water. ZnO NPs were synthesized by in situ hydrothermal treatment. The positively charged group of C-β-CD and the active hydroxyl group of HEC were used to distribute the ZnO NPs uniformly on the hydrogel matrix without significant agglomeration. The hydrogel had a smoothly ordered and compact morphology. It exhibited adequate mechanical, swelling, water retention and oxygen permeability properties in tests. In addition, the hydrogel had an efficient bactericidal effect. Release experiments showed that the encapsulation of menthol by C-β-CD allowed for a slow release of menthol. Biocompatibility tests had shown that the hydrogel was non-toxic to normal human cells.