Antimicrobial efficacy of ultrasonically deposited poly(vinyl alcohol)/poly(l-lysine)-based coatings for urinary catheters

Although urinary catheters are an essential part of hospital care, they are responsible for 75 % of hospital-acquired urinary tract infections. For that reason, there is a critical need for the development of long-term medical catheters exhibiting antibacterial properties, stability, and biocompatibility. Antimicrobial peptides, such as poly- l -lysine (PLL), have recently gained attention as promising agents for modifying biomedical devices due to their excellent biocompatibility and minimal toxicity. This study investigates the use of poly(vinyl alcohol) and poly- l -lysine (PVA/PLL) blend films as antimicrobial coatings for urinary catheters to enhance infection prevention, with PVA (0.5 %) and PLL (0.1 %) volume ratios between 400:1 and 100:1. An advanced ultrasonic coating technique (nozzle speed of 5 mm/s, flow rate of 0.25 cm 3 /min, and nozzle rotational speed of 90 rpm) was employed to create durable, uniform films on both flat and tubular surface of catheters. The resulting PVA/PLL coatings were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy, while their biocompatibility was assessed in vitro with human dermal fibroblasts. Microbiological tests indicated antimicrobial activity of PVA/PLL against Escherichia coli (2.5-fold decrease in surface coverage), Staphylococcus epidermidis (98.8 ± 0.5 % inhibition) and Candida albicans (2.5-fold reduction in cell viability). Additionally, computational studies examined the antimicrobial mechanism of PLL on bacterial membranes. Consequently, the optimized PVA/PLL-coated catheters demonstrated biocompatibility together with strong antimicrobial activity against pathogens associated with catheter-associated urinary tract infections. • Poly(vinyl alcohol) and poly- l -lysine blend films were used as urinary catheters coatings. • Uniform coverage was achieved using an ultrasonic coating technique. • Durable, uniform films were formed on both flat and tubular surface of catheters. • PVA/PLL coatings demonstrated biocompatibility together with strong antimicrobial activity. • Developed coating showed its applicability in reducing urinary catheter-associated infections.