Powdered Medical Adhesive with Long Lasting Adhesion in Water Environment

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