In-vitro antibacterial and anti-encrustation performance of silver-polytetrafluoroethylene nanocomposite coated urinary catheters

Abstract Background Catheter-associated urinary tract infections (CAUTIs) are some of the most common hospital-acquired infections, leading to increased morbidity and mortality. One major reason is that current urinary catheters are yet not capable of preventing CAUTIs. Aim To develop an anti-infective urinary catheter. Methods We deposited an efficient silver-polytetrafluoroethylene (Ag-PTFE) nanocomposite coating onto whole silicone catheters, and designed two in vitro bladder models to respectively test the antibacterial (against Escherichia coli ) and the anti-encrustation (against Proteus mirabilis ) performances. Each model was challenged with two different concentrations of bacterial suspension. Findings Compared with uncoated catheters, coated catheters could significantly inhibit bacterial migration and biofilm formation along the external catheter surfaces. The time to developing bacteriuria was an average of 1.8 days versus 4 days and 6 days versus 41 days, when the urethral meatus was infected with 106 and 102 cells/mL, respectively. For anti-encrustation tests, the coated catheter could significantly resist encrustation, although it did not strongly inhibit the increases of bacterial density and urinary pH. The time to blockage that was found independent of bacterial initial concentration in the bladder, was extended from 36.2±1.1 h (uncoated) to 89.5±3.54 h (coated) following bacterial contamination initially with 103 cells/mL in the bladder. Moreover, our coated catheter exhibited an excellent biocompatibility with L929 fibroblast cells. Conclusion It would be feasible to apply Ag-PTFE coated Foley catheters for further clinical trials to prevent CAUTIs during catheterization.