Reversibly Adhesive, Anti‐Swelling and Antibacterial Hydrogels for Tooth‐Extraction Wound Healing

Abstract Oral wound treatment faces challenges due to the complex oral environment such as moisture, bacteria and dynamic mechanics, thus, sealing wound quickly becomes necessary. Although some materials have achieved adhesion and antibacterial properties, how to effectively solve the contradiction between strong adhesion and on‐demand removal remains a challenge. Herein, a reversibly adhesive hydrogel was designed by free radical copolymerization of cationic monomer [2‐(acryloyloxy) ethyl] trimethylammonium chloride (ATAC), hydrophobic monomer ethylene glycol phenyl ether acrylate (PEA) and N ‐isopropylacrylamide (NIPAAm). The cationic quaternary ammonium salts provide electrostatic interactions, the hydrophobic groups provide hydrophobic interactions, and the PNIPAAm chain segments provide hydrogen bonding, leading to strong adhesion. Therefore, the hydrogel obtains an adhesion strength of 18.67 KPa to oral mucosa, and could seal wound fast within 10 s. Furthermore, unlike pure PNIPAAm, the hydrogel has a LCST of 40.3 °C due to the contribution of ATAC and PEA, enabling rapid removal with 40 °C water after treatment. In addition, the hydrogel realizes excellent anti‐swelling ratio (∼ 80%) and antibacterial efficiency (over 90%). Animal experiments prove that the hydrogel effectively reduces inflammation infiltration, promotes collagen deposition and vascular regeneration. Thus, the hydrogel as a multi‐functional dressing has great application prospects in oral wound management. This article is protected by copyright. All rights reserved