Anti-swelling, antithrombotic and antibacterial zwitterionic hydrogel coatings with a sandwich structure on polymer substrates.

Interventional medical catheters and blood-contact biomedical devices are crucial in clinical treatment, but they often face challenges such as thrombosis, infection and inflammation. In this study, a sandwich-structured hydrogel coating was successfully prepared with antithrombotic, antimicrobial and anti-swelling properties. The coating consisted of a polydopamine adhesion base layer, an antimicrobial and anti-swelling middle layer, and an anti-adhesive top layer. The middle layer contains Pluronic F127 diacrylate (FDA) micelles and the poly(methacryloyl sulfobetaine) (pSBMA) hydrogel, wherein glucose oxidase (GOx) encapsulated in FDA micelles is incorporated into the coating for achieving a sustained antimicrobial effect. The top layer consists of zwitterionic polycarboxybetaine (pCBMA), which prevents non-specific protein adhesion and acts as a barrier to reduce the release of GOx and prolong its antimicrobial effect. The coating was applied onto the surface of silicone catheters, which showed excellent durability as well as antithrombotic and antimicrobial properties, providing a new solution to improve the safety and efficacy of clinical treatments.