Durable antibacterial polyurethane based on crosslinked epsilon-poly-l-lysine for urinary catheter coating

Bacterial infections associated with indwelling catheters pose a significant clinical challenge, often leading to severe morbidity and mortality. The development of effective antibacterial coatings is thus of paramount importance. This study presents a novel polyurethane (PU) incorporating cationic epsilon-poly- l -lysine (CPL)/docusate sodium (DS). The incorporation of CPL/DS nanoparticles enhanced the hydrophilicity of the PU material. Among the PUs we prepared, PU-1.75 boasted optimized performances featuring high bactericidal efficiency against S. aureus and E. coli . Notably, in vitro tests confirmed that PU-1.75 maintains nearly 100 % bactericidal activity against S. aureus even after 21 days of incubation in physiological saline solutions. Furthermore, PU-1.75-coated urinary catheters effectively inhibit the growth of S. aureus and E. coli under static and dynamic flow conditions. The in vivo SD rat model approved the good biocompatibility of PU-1.75-coated catheters. These findings collectively indicate that PU-1.75 is a highly promising, safe, and durable antibacterial capable of providing long-term protection against catheter-associated infections.