Optimizing Cnt Loading In Antimicrobial Composites For Urinary Tract Application

Featured ApplicationCarbon nanotube composites produced in the scope of this work can potentially be used as a starting point for designing urinary tract devices with inherent antibiofilm activity.Several methodologies have been implemented with the intent of preventing or reducing the formation of biofilms on indwelling urinary devices. The use of carbon nanotubes (CNTs) in the biomedical field has been increasing, particularly in the production of antimicrobial and antifouling coatings. Despite their proven antimicrobial properties, their use as coating materials for urinary tract devices (UTDs) is still poorly documented. In the present work, CNT/poly(dimethylsiloxane) (PDMS) composite materials containing different CNT loadings were prepared and further tested against Escherichia coli under conditions prevailing in UTDs. Besides CNT loading optimization, textural modifications were also introduced on the surface of CNTs to improve the antibiofilm properties of the final composites. Material characterization included the textural evaluation of CNTs and the assessment of surface morphology by scanning electron microscopy, while the surface hydrophobicity was determined by contact angle measurements. Biofilm analysis was performed by determining the number of culturable and total cells and by confocal laser scanning microscopy. Results revealed that, by filling the PDMS matrix with 3 wt% CNT loading, a significant reduction in cell culturability (39%) can be achieved compared to PDMS. Additionally, the textural modifications induced by ball-milling treatment proved to be effective on the inhibition of biofilm formation, reducing the amount of biofilm per surface area, biofilm thickness and surface coverage in 31, 47 and 27%, respectively (compared to surfaces where CNTs were not ball-milled).