A Superhydrophilic Zwitterionic Hydrogel Coating for Enhancing Long-Term Anti-bacterial Adhesion and Anti-encrustation Properties of Ureteral Stents

Prolonged indwelling of ureteral stents often leads to encrustation, which can cause functional failure and poses a significant clinical challenge. Zwitterionic polymers exhibit excellent anti-fouling performance due to their strong surface hydrations. Inspired by this, a multifunctional hydrogel coating based on a trimethylamine N-oxide zwitterionic polymer was developed for polyurethane stents to mitigate encrustation. The coating was fabricated using an innovative approach that combines superwetting-assisted interfacial polymerization strategy with dip coating technology, significantly improving the adhesion strength between the coating and the stent surface to ensure long term stability. Notably, the coating strongly interacts with water molecules to form a robust hydration layer, effectively inhibiting bacterial adhesion. In a 90-day simulated urinary flow test, the coating demonstrated outstanding anti-encrustation performance, reducing encrustation by 92%, while maintaining excellent biocompatibility. This coating technology provides an effective and durable solution for preventing complications associated with ureteral stents and shows broad application potential in the field of urological medical devices.