Plasma-Activated\nAVC Hydrogel for Reactive Oxygen\nand Nitrogen Species Delivery to Treat Allergic Contact Dermatitis

Allergic contact dermatitis (ACD)\nis a common inflammatory\nskin\ndisease that accounts for approximately 20% of all occupational skin\ndiseases. As an adverse and recurrent inflammatory dermatological\nagent, ACD shows insufficient response to current therapies largely\nowing to abnormal inflammatory activation and accompanying bacterial\ninfection in lesions. Cold atmospheric plasma is a noninvasive fledgling\nreactive oxygen and nitrogen species (RONS)-based therapeutic technique\nfor ACD treatment; however, its clinical adoption has been hindered\ndue to the risk of electrical burns and insufficient delivery of the\nplasma-generated RONS. To address these limitations, we constructed\nplasma-activated AVC (PA-AVC) hydrogels loaded with plasma-generated\nRONS for ACD treatment as an alternative to the common direct plasma\nirradiation treatment. The proposed PA-AVC hydrogels were produced\non a biodegradable acryloyldimethylammonium taurate/VP copolymer (AVC)\nwith the aid of a novel air discharge plasma without the involvement\nof any catalyst. In vitro data showed that abundant RONS were produced\nand incorporated into the PA-AVC hydrogels via complex gas–liquid\nreactions between the air discharge plasma and hydrosolvent; additionally,\nthe PA-AVC hydrogels exhibited excellent storage, slow release and\ntransdermal delivery of RONS as well as good antibacterial effects.\nMoreover, in vivo experiments demonstrated that PA-AVC hydrogels effectively\nalleviated the ACD symptoms, such as skin redness and swelling, reduced\nepidermal thickening and inhibited mast cell infiltration and IL-9,\nTNF-α, and TSLP expression with no evident systemic toxicity.\nOur results revealed that long-acting plasma-activated AVC hydrogels\ncould be effective therapeutic agents for local ACD treatment.