Highly Efficient Antibacterial Hydrogel-based Multifunctional Coatings for Ureteral Stent to Inhibit Severe Infectious Encrustation

Ureteral stents are prone to encrustation due to urinary crystallization and bacterial infection, leading to severe complications and restricting long-term use. In this study, a multifunctional hydrogel-based coating was developed, which integrates the crosslinking of polyacrylic acid coupled with zinc ions (PAA(Zn 2+ )) possessing antibacterial properties and polyvinylpyrrolidone (PVP) with hydrophilic lubrication properties on the PU stent (PPAZ/PU). This novel PPAZ/PU coating was devised to mitigate the challenges of bacterial infectious encrustation associated with stent placement in clinical settings. The coating was synthesized via complex decomposition and addition polymerization, forming a stable zinc-ion-rich crosslinked network. The intertwining of PVP and PAA(Zn²⁺) molecular chains, along with hydrogen bond formation, enhanced the hydrogel's cohesion and peel strength up to 1000 N/m. The hydrophilicity and lubricity of the PPAZ/PU-coated stent was markedly enhanced for clinical applications, with a reduction in contact angle and friction coefficient by a factor of 3.25 and 2.62, respectively. In vitro antibacterial assays and simulated infectious encrustation experiments revealed that the PPAZ/PU-coated stent had an antibacterial efficacy of over 99% and halved the surface encrustation per unit area. This PPAZ/PU hydrogel-based coating strategy presents an efficacious solution to the anti-encrustation demands of ureteral stents, particularly in severe urinary tract infection scenarios.