AbstractAimsThe care of patients undergoing long-term urethral catheterization is frequently complicated byProteus mirabilisinfection. This organism forms dense, crystalline biofilms, which block catheters leading to serious clinical conditions. However, there are currently no truly effective approaches to control this problem. Here, we describe the development of a novel theranostic catheter coating, to simultaneously provide early warning of blockage, and actively delay crystalline biofilm formation.Methods and ResultsThe coating comprises of a pH sensitive upper polymer layer (poly(methyl methacrylate-co-methacrylic acid); Eudragit S 100®) and a hydrogel base layer of poly(vinyl alcohol), which is loaded with therapeutic agents (acetohydroxamic acid or ciprofloxacin hydrochloride) and a fluorescent dye, 5(6)-carboxyfluorescein (CF). The elevation of urinary pH due toP. mirabilisurease activity results in the dissolution of the upper layer and release of cargo agents contained in the base layer. Experiments usingin vitromodels, which were representative ofP. mirabiliscatheter-associated urinary tract infections, demonstrated that these coatings significantly delay time taken for catheters to block. Coatings containing both CF dye and ciprofloxacin HCl were able to provide an average ofca. 79 h advanced warning of blockage and extend catheter lifespanca. 3.40-fold.ConclusionsThis study has demonstrated the potential for theranostic, infection-responsive coatings to form a promising approach to combat catheter encrustation and actively delay blockage.