ROS-scavenging hydrogel to accelerate wound healing and reduce scar formation

Both repair of chronic wounds and prevention of excessive scarring after skin trauma remain great challenges, which can lead to psychological diseases and serious economic burden. The accumulation of excessive reactive oxygen species (ROS) at the wound site in particular presents additional obstacles for the above two issues as ROS can hinder the healing of both normal and difficult-to-heal diabetic wounds and lead to the formation of wound scarring. To address these dilemmas, here, a novel multifunctional ROS-scavenging hydrogel (CT-X) was readily prepared via cross-linking carboxymethyl chitosan (CMCS) with the excellent natural biological crosslinking agent (genipin) and introducing a ROS-responsive linker (TPA) to the system. In vitro studies have shown that the obtained hydrogel could remove ROS from cells under a variety of extremely harsh conditions and reduce various intracellular damages caused by ROS. Benefitting from the excellent ROS scavenging ability, this hydrogel could upregulate the expressions of anti-inflammatory genes, reduce M1 phenotype macrophages, and alleviate adverse inflammatory responses. Moreover, this hydrogel could inhibit the expressions of genes related to scar formation. More interestingly, the in vivo-study further suggested that this ROS-scavenging hydrogel could not only promote the healing of normal and diabetic wounds, but also reduce wound scarring. Overall, the present approach furnishes new light on designing ROS-scavenging hydrogels with promising potential in chronic wound and dressing applications with less scar formation.