Ionic liquids enable the preparation of a copper-loaded gel with transdermal delivery function for wound dressings

Antibacterial hydrogel dressings play an important role in wound healing and infection treatment. The majority of hydrogels are obtained through chemical cross-linking and complex synthesis or processing. Copper ions (Cu²⁺) have been involved in sterilization; however, their direct use may lead to high local concentrations and heavy metal toxic side effects. Herein, dopamine (DA) was polymerized in situ along a polyvinyl alcohol (PVA) chain and chelated copper ions (Cu²⁺) to form a mixture. Ionic liquid (IL) choline-glycolate (CGLY) was added to the mixture to form an ionic gel. CGLY promotes gel formation through intermolecular hydrogen bonds with the polymer chains and avoids the use of toxic chemical crosslinking agents. Meanwhile, CGLY can also promote the release of Cu²⁺ and generate hydrogel free radicals (˙OH) in the wound through chemodynamic therapy to kill drug-resistant bacteria. In addition, the excellent transdermal property of CGLY enables the released Cu²⁺ to stimulate cell migration and accelerate wound healing. The gel exhibits favorable biocompatibility and its use has been demonstrated in skin infection therapy of mice.