Development of Zwitterionic Poly(SBMA-AA) Coatings for Ureteral Stents Enhanced Lubrication and Antifouling Properties

Ureteral stents are employed to relieve ureteral stenosis, but they face challenges including high friction that causes endothelial damage, microbial colonization, and encrustation. The long-term use of ureteral stents usually leads to pain, increased urinary frequency, and even secondary surgery. To address these issues, ureteral stents require lubricating antifouling surfaces to reduce tissue damage, bacterial infection and encrustation. Herein, we report an antifouling and lubricating hydrophilic coating based on the zwitterionic polymer poly(sulfobetaine methacrylate-acrylic acid) (poly(SBMA-AA)) prepared using UV-initiated polymerization. Controlled monomer feed ratios were used to study the antimicrobial and anti-encrustation capacities. The poly(SBMA-AA) coatings were hydrophilic, which facilitated the formation of a hydrated layer, thereby reducing friction. The friction test revealed that the coatings could achieve an initial friction coefficient as low as 0.023. After 15 days of immersion in artificial urine, the coefficient of friction remained stable at approximately 0.027, indicating its long-term lubricity and potential to reduce tissue damage. Furthermore, as the AA monomer molar ratio increased, the coatings exhibited enhanced antibacterial adhesion, and demonstrated superior anti-encrustation performance in a 30-day urinary crystallization model. This study proposes a novel approach for developing multifunctional ureteral stent coatings that integrate long-term lubrication, antibacterial adhesion activity, and anti-encrustation capabilities.