Antimicrobial andAntibiofilm Activities of UrinaryCatheter Incorporated with ZnO-Carbon Nanotube

Urinary tract infections are among the most common nosocomial infections, with the majority being catheter-associated urinary tract infections (CAUTIs). This study demonstrated that an antimicrobial and antibiofilm urinary catheter containing zinc oxide-carbon nanotubes (ZnO-CNT) can inhibit CAUTIs in patients. ZnO-CNT polymers were synthesized by mixing ZnO and CNT using a high-shear mixer, and the synthesized ZnO-CNT polymers were incorporated into a silicone matrix to produce a ZnO-CNT urinary catheter. Scanning electron microscopy was used to evaluate the morphology and atomic composition of the polymer and urinary catheter, which contained 1.23% Zn element. Dynamic light scattering analysis showed an average particle size of 253.4 nm with a zeta potential of +21.4 mV. To assess antimicrobial activity, the ZnO-CNT polymer and urinary catheter were tested using minimum inhibitory concentration (MIC) and antibiofilm assays. The ZnO-CNT polymers exhibited MIC values of 0.0078, 1, 0.00625, and 0.0039% against E. coli, P. aeruginosa, E. faecalis, and S. aureus, respectively. Antibiofilm assays conducted at concentrations ranging from 1/4 to 2 × MIC demonstrated effective inhibition of biofilm formation at 1 × MIC or lower concentrations in E. coli and P. aeruginosa. The ZnO-CNT urinary catheter inhibited biofilm formation by 53.42 and 56.44% after 120 h of incubation compared to the silicone urinary catheter against E. coli and P. aeruginosa, respectively. These findings suggest that the ZnO-CNT urinary catheter could not only replace commonly used silicone catheters to reduce patient discomfort but also serve as a viable alternative to antimicrobial urinary catheters coated with metal alloys such as silver, gold, or palladium.