Hydrophilic PAAm/SA‐Ca²⁺ Hydrogel Coating for Ureteral Stents With Lubrication, Antimicrobial Adhesion, and Anti‐Stone Functions

Conventional ureteral stents frequently cause mucosal damage during placement due to surface hydrophobicity and elevated friction coefficients. Additionally, post‐insertion complications such as bacterial adhesion and calculus deposition pose significant clinical risks. To address these challenges, we developed a polyacrylamide/sodium alginate‐Ca 2+ (PAAm/SA‐Ca 2+ ) dual‐network hydrogel as a functional coating for ureteral stents. By modulating calcium chloride (CaCl 2 ) concentration, we optimized the PAAm/SA‐Ca 2+ dual‐network hydrogel's cross‐linking density, resulting in enhanced hydrophilicity, reduced swelling ratio (from 48.5% to 17.3%), and a lower coefficient of friction (COF) (from 0.19 to 0.06). The hydrogel coating exhibited excellent stability and sustained lubricity with a uniform thickness of approximately 16 μm. Notably, the coating reduced calculus deposition by 74% over a 7‐day period and demonstrated exceptional antibacterial efficacy, achieving 97% inhibition against Escherichia coli ( E. coli ) and 98% against Staphylococcus aureus ( S. aureus ). Furthermore, the coating displayed favorable hemocompatibility. These findings highlight the potential of PAAm/SA‐Ca 2+ dual‐network hydrogel coatings for improving ureteral stent performance.