Surface Grafted N‐Oxides have Low‐Fouling and Antibacterial Properties

Abstract Low‐fouling materials are often generated by surface zwitterionization with polymers. In this context, poly‐N‐oxides have recently attracted considerable attention as biomimetic stealth coatings with low protein adsorption. Herein, this study reports that poly‐N‐oxides can be grafted from plasma‐activated plastic base materials. The resulting hydrophilic surfaces have low‐fouling properties in bacterial suspensions and suppress the formation of biofilms. Moreover, efficient antibacterial activity against Gram‐negative and Gram‐positive bacteria caused by release of reactive oxygen species is observed. The latter effect is specific for polymeric N‐oxides and is most likely triggered by a reductive activation of the N‐oxide functionality in the presence of bacteria. In contrast to other zwitterionic polymers, N‐oxides combine thus low‐fouling (stealth) properties with antibacterial activity. The bioactive N‐oxide groups can be regenerated after use by common oxidative disinfectants. Poly‐N‐oxides are thus attractive antibacterial coatings for many base materials with a unique combined mechanism of action.