Powdered Medical\nAdhesive with Long Lasting Adhesion\nin Water Environment

Medical adhesives have been used\nunder surgical conditions.\nHowever,\nit is always a big challenge to maintain long-term adhesion in a water\nenvironment. Besides, it usually takes a long time to complete the\nadhesion, and the operation might be complicated. In this study, tannic\nacid and gelatin solution under acidic conditions were mixed, flocculated,\nlyophilized, and crushed; thus, a powdered medical adhesive (POWDER)\nwas prepared with long-lasting adhesion in a water environment, convenience,\nand low price. Tannic acid bound gelatin and maintained adhesive force\nprimarily through hydrogen bonding and reacted with amino sulfhydryl\nand other amino acid residues after oxidation into aldehyde, exhibiting\nexcellent underwater adhesion. Oxidized dextran (ODex) powder rich\nin an aldehyde group was introduced to provide covalent binding in\nthe adhesive. In vitro and in vivo studies showed that POWDER could\nquickly adhere to various tissues in the water environment. In vitro\nskin adhesion experiments demonstrated that it could achieve effective\nadhesion in a water environment for up to 60 days. Its blood compatibility,\nlow cytotoxicity, and biodegradability were also verified. The POWDER\ndeveloped in this study is of great significance for patients who\nneed rapid wound treatments.