COCu: A Robust Self‐Regenerative Hydrogel with Applicability as Both Hydrated Gel Dressing and Dry Suture for Seamless Tissue Fixation and Repair

Abstract

Self-regenerative hydrogels have recently been developed, and represent a special type of self-healing hydrogels with the ability to restore a dehydrated hydrogel with physical damage. In this study, a self-regenerative hydrogel (COCu) based on two chitosan polymers assembled by slow-released Cu 2+ is developed. The COCu hydrogel displays an excellent regeneration ability after being dehydrated and fractured. By simple hydration at room temperature, the fragments of the dehydrated gel fuse into one seamless whole, thereby preserving the mechanical properties and functionalities of the original hydrogel. The regeneration process can be conducted repeatedly after different methods of dehydration (natural volatilization, heat drying, lyophilization) and various modes of deconstruction (flakes, powder, lumpy sponge, etc.). Furthermore, the COCu hydrogel provides ultra-stretchability, and it can be stretched into thin (0.01-0.1 mm) filaments, which, when dried (dtCOCu), can be used as suture lines. Moreover, when used as a dry suture, it regenerates into the hydrogel in the presence of the tissue fluid, forming an excellent sealant to immobilize tissues and seamlessly seal wounds. The fast self-regeneration allows for its facile application as both a hydrated gel dressing and dry suture, and offers customized strategies for fixing and repair of different wounds in soft tissues.

Bioactive hydrogels based on polysaccharides and peptides for soft tissue wound management

“…Chitosan usually acts as a cross-linker with aldehydes and diisocyanate functional biopolymers to prepare hydrogels. 3 Many chemical modified methods have been taken on chitosan-based hydrogels to improve their hemostasis and adhesion performance, including catechol 16–23 and pyrogallol 24–26 decoration, amino 27 and aldehyde 28 modification, photoactive methacrylate 17,29–33 and o -nitrobenzyl 34 functionalization, etc. For example, Peng et al 35 fabricated a polyethyleneimine/polyacrylic acid/quaternized chitosan (PEI/PAA/QCS) powder through a freeze drying-grinding procedure with ultrafast self-gelling and wet adhesive properties (Fig.…”