In biomedicine fields, biofouling can easily occur on devices such as sensors and catheters, causing some iatrogenic infections, which menace the lives and health of patients greatly. Therefore, it is of great significance to solve the problems of bacterial infection on the surfaces of medical devices. In this paper, "self-defensive" and antifouling zwitterionic hydrogel coatings were prepared by network interpenetration of the hydrogel and the polymeric substrates. The zwitterionic polysulfobetaine methacrylate (PSBMA) hydrogel coatings resisted most of the bacteria to adhere on the substrates. When a few bacteria were lucky to escape the antifouling defense and adhered to the coatings, gentamicin sulfate (GS) would be released under the trigger of a weakly acidic environment caused by bacterial metabolism to kill these bacteria. Simultaneously, the coatings of the bacteria-adhering sites would be degraded by hyaluronidase secreted by these bacteria and peeled off to remove the bacteria and renew the antifouling surfaces. The antifouling properties and mechanism of the self-defensive behavior of the hydrogel coatings on polymeric substrates were investigated. Furthermore, the in vitro and in vivo antibacterial performances, as well as the biocompatibility of the coatings, were demonstrated. The results suggested that the self-defensive antifouling zwitterionic hydrogel coatings hold great potential to be used on the surfaces of polymeric medical devices.
Keywords: antibacterial; antifouling; bacteria-responsive; hydrogel coatings; self-defensive; zwitterionic.