Silicon surfaces coated with polydopamine and poly (2-hydroxyethyl methacrylate) for medical device applications

In order to prevent catheter-associated urinary tract infections caused by biofilm, in this study, polydopamine (PDA) was polymerized in the presence of ammonia on the surface of the silicone samples selected from the urinary catheters used in medicine. The OH groups in polydopamine were alpha-brominated by nucleophilic substitution reaction in the presence of alpha-bromoisobutyryl bromide. Then, poly (2-hydroxyethyl methacrylate) (PHEMA) was polymerized on the functionalized polydopamine by ATRP polymerization. PHEMA-PDA-coated catheter was evaluated at each step using attenuated total reflection-Fourier transform infrared (ATR-FTIR), scanning electron microscope, thermal gravimetric analysis, and atomic force microscopy, and its hydrophilicity was assessed by water contact angle. The contact angle of water decreases from 115 degrees for uncoated catheter to 84 degrees for PHEMA-PDA-catheter. PHEMA-PDA-coated catheter prevented Pseudomonas aeruginosa adhesion and colonization during 24 and 48 h and Escherichia coli during 24 h compared to the uncoated sample. It is concluded that functionalization of catheters with PDA-PHEMA appears as a favorable candidate for indwelling urinary catheters.