Polymer-Coated Urinary Catheter Reduces Biofilm Formation and Biomineralization: A First-in-Man, Prospective Pilot Study

Biofilm formation and biomineralization on urinary catheters may cause severe complications including infection and obstruction. Here, we describe an in vitro evaluation and prospective pilot clinical study of a silicone catheter coated with a biofilm-resistant polymer. Biofilm biomass and biomineralization on uncoated and coated catheters were quantified by confocal microscopy using fluorescently tagged bacteria or stained for biofilm and minerals. Biomineral identity was determined using scanning electron microscopy and X-ray spectroscopy. Biofilm formation and biomineralization were evaluated in vitro using uropathogens Proteus mirabilis and Pseudomonas aeruginosa and on catheters recovered from hospitalized patients. Fibrinogen in patient urine and on catheters was quantified using an immunofluorescence assay. In vitro P. mirabilis and P. aeruginosa formed significantly less biofilm and biomineral and failed to block coated compared with uncoated catheters in a bladder model after 89 h. Biofilm-resistant polymer-coated catheters (n = 83) recovered from hospitalized patients exhibited significantly lower biofilm biomass and biomineralization compared with uncoated silicone catheters (n = 78). Electron microscopy with elemental analysis of recovered catheters revealed calcium oxalate crystals on coated compared with the struvite and apatite crystals on uncoated catheters associated with catheter blockage. Lower levels of biofilm-promoting fibrinogen in postcatheterization urine and on catheters from patients receiving coated catheters was observed compared with those receiving uncoated catheters indicative of a reduced inflammatory response. These data provide evidence that polymer-coated urinary catheters exhibit enhanced resistance to fibrinogen deposition, biofilm formation, and encrustation, reducing the risks associated with catheter-associated urinary tract infections and obstruction.