Mussel-Inspired Epoxy Bioadhesive with Enhanced Interfacial Interactions for Wound Repair

The balance between high mechanical properties and strong adhesion strength is crucial in designing and preparing a bio-based hydrogel adhesive for wound closure. Although the adhesion performance of bioad-hesives has been remarkably improved by modification with catechol groups, their mechanical properties are yet to meet the biomedical requirements. In this study, mussel-inspired epoxy bioadhesives (CSD-PEG) were synthesized based on catechol-modified chitosan oligosaccharide (CSD) and polyethylene gly-col diglycidyl ether (PEGDGE) through nucleophilic substitution. Notably, the CSD-PEG adhesive showed high mechanical and adhesion strengths, which were up to 50.7 kPa and 136.7 kPa, respectively. It was confirmed that a certain amount of the epoxy and catechol groups provided multiple interfacial interac-tions among the adhesives, substrates, and polymer chains for enhancing the performance of adhesives. The adhesives showed good binding and repairing effects for wound closure and favorable biocompatibil-ity in vivo . The prepared CSD-PEG adhesives are expected to be a promising candidate for surgical tissue repair, wound closure, and tissue engineering fields. Statement of significance Current reported adhesives composed of biopolymers generally suffer from poor mechanical properties or weak tissue adhesiveness. Therefore, to achieve simultaneously high mechanical and adhesion prop-erties in a bio-based adhesive for wound closure is a big challenge. In this study, mussel-inspired adhe-sive hydrogels (CSD-PEG) were prepared based on catechol-modified chitosan oligosaccharide (CSD) and polyethylene glycol diglycidyl ether (PEGDGE). The tensile strength and adhesive strength of CSD-PEG on porcine skin reached 50.7 kPa and 136.7 kPa, respectively, which were higher than those for most re-ported biopolymeric adhesives, mainly due to the multiple interfacial interactions between the catechol and epoxy groups. The CSD-PEG bioadhesives also showed good binding and repairing effects for wound closure and tissue regeneration in vivo . (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.