Smart bacteria-responsive coatings for combating catheter-associated urinary tract infections

As one of the leading hospital-acquired infections (HAI), catheter-associated urinary tract infections (CAUTIs) can not only give rise to high treatment costs, but may also lead to serious after effects like pyelonephritis, sepsis, bacteremia, and even death. In order to reduce the infection risk, a lot of efforts have been devoted to the development of antibacterial urinary catheters such as antibiotic-coated catheters. With the emergence of antibiotic resistance, the design of alternative antibacterial strategies such as stimuli-responsive coatings for combating CAUTIs has attracted increasing interest in recent years. In this review, we summarize recent advances of bacteria-responsive coatings that are specially designed for urinary catheters. Based on the specific microenvironments of CAUTIs, various responsive coatings triggered by pH changes and bacterial metabolites such as enzymes and toxins, have been developed. The design principles, fabrication approaches and antibacterial performance of such smart coatings are discussed based on representative examples. Finally, a brief perspective is presented on the challenges and future of bacteria-responsive coatings for urinary catheters.