An Infection-Responsive Approach To Reduce Bacterial Adhesion in Urinary Biomaterials

Infection is an inevitable consequence of chronic urinary catheterization with associated problems of recurrent catheter encrustation and blockage experienced by approximately 50% of all long-term catheterized patients. In this work, we have exploited, for the first time, the reported pathogen-induced elevation of urine pH as a trigger for "intelligent" antimicrobial release from novel hydrogel drug delivery systems of 2-hydroxyethyl methacrylate and vinyl-functionalized nalidixic acid derivatives, developed as candidate infection-resistant urinary catheter coatings. Demonstrating up to 20-fold faster rates of drug release at pH 10, representing infected urine pH, than at pH 7 and achieving reductions of up to 96.5% in in vitro bacterial adherence, our paradigm of pH-responsive drug delivery, which requires no external manipulation, therefore represents a promising development toward the prevention of catheter-associated urinary tract infections in vivo.