An injectable antibacterial hydrogel with bacterial-targeting properties for subcutaneous suppuration treatment

Purulent infections present challenges to medical procedures and burden patients with drainage procedures. An injectable antibacterial hydrogel can be directly administered to the infected tissue through a syringe, making it one of the most effective strategies for treating subcutaneous infections. In this study, we utilized an injectable hydrogel (PHP gel) with targeted bactericidal properties for surgery-free treatment of subcutaneous infections. The PHP gel was cross-linked using the Schiff base reaction between amino-functionalized polyhydromethylpyrimidine (PHP-NH2) and oxidized dextran (o-Dex). PHP-NH2 possesses the ability to kill bacteria through electrostatic interactions, while o-Dex enhances bacterial targeting by binding to lectins on the bacterial outer membrane via sugar units. In vitro experiments demonstrated that the PHP gel effectively eradicated 100 % of pathogenic bacteria within 2 h. Moreover, when used in vivo for treating purulent subcutaneous infections, the injectable PHP gel exhibited remarkable efficacy by preventing infection progression and eliminating pustule tissue within 24 h. Importantly, no significant adverse effects on blood or organ systems were observed in mice treated with PHP gel. Therefore, this polysaccharide- and polyhydropyrimidine- based hydrogel material holds immense potential as a novel antibacterial agent for managing purulent subcutaneous infections.