Plasma surface modification as a new approach to protect urinary catheter against Escherichia coli biofilm formation

BACKGROUND AND OBJECTIVES Biomaterials are widely used in medical devices such as urinary catheters. One of the main problems associated with long term using of the urinary catheters is biofilm formation on their surfaces. Many techniques have been presented to reduce the biofilm formation. One of the most revolutionary techniques allowing such surface fictionalization is plasma surface modification. MATERIALS AND METHODS In this study, a glow discharge plasma (GDP) effect on Escherichia coli biofilm formation on the surface of urinary catheter in the pressure of 1.6 × 10-1 Torr of nitrogen, discharge voltage about 1.2 kV and current of 150 mA for 20 minutes has been investigated. Crystal violet binding assay and sonication method were performed in order to evaluate the amount of biofilm formation on tested biomaterials. RESULTS Characterization of modified surfaces by Attenuated Total Reflectance Fourier Transform Infrared Spectrometry (ATR-FTIR) and atomic force microscopy (AFM) revealed a noticeable change in hydrophobicity and roughness of catheter surfaces achieved by nitrogen plasma. The results of crystal violet binding assay and sonication method showed that the amount of biofilm formation on modified surface was about 86% less than the pristine sample. CONCLUSION Plasma surface modification can reduce the risk of infections in patients with long-term use of urinary catheters.