A Bridge-like Copolymer for Surface Functionalization of Ureteral Stents with Enhanced Lubrication, Antibacterial,...

Commercial ureteral stents frequently encounter clinical issues, such as mucosal injury due to friction, bacterial colonization resulting in infections, and mineral encrustation compromising long-term use. To effectively address these challenges, we developed a bridge-like copolymer coating, namely, P(DMA-bMPC-bDMA) (PDMD), which was synthesized via reversible addition-fragmentation chain transfer polymerization. The PDMD architecture strategically positioned dopamine methacrylamide groups at both ends, generating a "molecular clamp" that provided robust dual-end self-adhesion and ensured uniform, stable anchoring to the polyurethane substrate. Compared to conventional single-end adhesive coatings, this "molecular clamp" approach significantly enhanced the integrity and durability under dynamic physiological conditions. In addition, the bridge-like structure also optimally introduced the central segment of 2-methacryloyloxyethyl phosphorylcholine, forming a highly effective hydration layer that dramatically reduced friction by 92% (coefficient of friction ∼ 0.032) and acted as a physical barrier to inhibit bacterial adhesion. Consequently, the PDMD-modified polyurethane samples inhibited the adhesion of common uropathogens such as Escherichia coli (>98.8%), Staphylococcus aureus (>92.2%), and Proteus mirabilis (>98.5%) and effectively prevented the formation of encrustation in dynamic in vitro and in vivo urinary tract infection models. Overall, this multifunctional surface treatment combining dual-end self-adhesion stability with both superlubrication and antifouling performances provides a substantial improvement over previous traditional coatings, enhancing biocompatibility, reducing complications, and markedly improving patient comfort and clinical outcomes for commercial ureteral stents.