CONSTRUCTION OF DOUBLE-NETWORK HYDROGELS THROUGH HOST-GUEST COMPLEXATION AND SCHIFF-BASE BONDING FOR POTENTIAL BIOMEDICAL APPLICATIONS

Abstract

A double-network hydrogel was designed and successfully fabricated, featuring a first network formed through host-guest interactions and a second network based on Schiff base covalent bonding. The host-guest network was formed between β-cyclodextrin (βCD)-modified alginate (βCD-Alg) and adamantane-modified alginate (AD-Alg). The covalent network of this hydrogel was constructed by the chemical reaction between aldehyde-modified 4arm-poly(ethylene glycol) (4-PEG-CHO) and carboxyl-modified chitosan (CS-COOH). This hydrogel network exhibited injectability, rapid in situ gelation, and self-healing properties. The double-network hydrogel was compared with the single-network interpenetrating polymer network (IPN) hydrogel formed by the same polymer compositions that was crosslinked only by Schiff base covalent bonding without the first host-guest networking. The storage modulus of the double-network hydrogel reached 934 Pa, significantly surpassing that of the IPN hydrogel (677 Pa). In drug release experiments, the double-network hydrogel loaded with vancomycin (Van) exhibited sustained release of Van for up to 96 hours and demonstrated pH-responsive release. In antibacterial tests, the Van-loaded hydrogel displayed excellent antibacterial properties. This hydrogel holds immense potential for application in wound healing and drug release.