A self-assembled hydrogel dressing as multi-target therapeutics to promote wound healing

Wound healing is one of the major challenges in biomedicine owing to the absence of ideal wound dressings which can integrate easy absorption, satisfied injectability, rapid self-healing property, and multiple therapeutic effects into one system. Here, we explore a self-assembled supramolecular hydrogel composed of herbal cinnamaldehyde (CA) and folic acid (FA). This enables the Schiff base and the Ionic crosslinking as a dynamic double cross-linked network. This nano-scale hydrogel (C-FA-gel) maintains good adhesion and is apt to get peeled off from tissues without any residuals. Further experiments show a percutaneous absorption within 12 h after the hydrogel dressing perfectly fills the irregular wound by injection on pig skin. For muti-target therapeutics, the drug sustained-release of C-FA-gel exhibits broad-spectrum antibacterial activities without evident cytotoxicity. Besides, the topical dressing on rat skin promotes wound healing via multifunctional effects including inflammatory reduction, facilitation of the angiogenesis improvement, and regeneration promotion of skin appendages. Moreover, the C-FA-gel induces anti-inflammatory macrophages from pro-inflammatory macrophages. Therefore, we successfully present a self-assembled hydrogel using the 'one system' strategy. This study offers a green and efficient design for the potential to be applied to complicated wound treatment.