Poison Turned Panacea: Arsenic Trioxide Loaded Hydrogel for Inhibiting Scar Formation in Wound Healing

Without intervention, the natural wound healing process can often result in scarring, which can have detrimental effects on both the physical and mental well-being of patients. Therefore, it is crucial to develop biomaterials that can promote healing without scarring. Regulating the Yes-associated protein-1/PDZ-binding motif (YAP/TAZ) signaling pathway is possible to reduce excessive fibrosis of fibroblasts and proliferation of vascular endothelial cells, ultimately impacting scar formation. Arsenic trioxide (ATO), an ancient drug with medicinal and toxic properties, has shown promise in regulating this pathway. An ATO-loaded hydrogel dressing (ATO@CS/SA) was created to facilitate scarless wound healing, utilizing chitosan (CS) and sodium alginate (SA) to prevent direct contact of ATO with the wound tissue and minimize potential side effects. In vitro studies demonstrated that low concentrations of ATO did not impact cell viability and even promoted proliferation and migration. Co-culturing the hydrogel with fibroblasts and vascular endothelial cells led to decreased expression levels of YAP and TAZ. Animal studies over a 90-day period revealed significant inhibition of scar formation with this system. Histological experiments further confirmed that the decreased expression of YAP and TAZ was responsible for this outcome. In conclusion, when administered at the appropriate dose, ATO can be repurposed from a traditional poison to a therapeutic agent, effectively suppressing excessive cell fibrosis and blood vessel proliferation and offering a novel approach to scar-free treatment.