Copper-phenolic coating constructed on silicone urinary catheters to prevent catheter-associated infections

Catheter-associated infections (CAIs) are serious issues in clinics, significantly affecting patient morbidity, mortality, and incurring substantial treatment costs. Hence, the development of a novel strategy to endow surfaces with antibacterial function is particularly important for catheter materials. In this work, Tannic acid (TA) and various concentrations of copper (Cu) were used to construct metal-phenolic network (MPN) coatings to impart silicone catheters antibacterial surfaces (TA/Cu₅, TA/Cu₅ and TA/Cu₂₅). The prepared copper-phenolic coatings exhibited desirable biocompatibility towards mammalian cells and remarkable antibacterial properties against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and even “superbug” such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The antibacterial properties of the MPN coatings were attributed to the combined effects of Cu and TA. Among all MPN coated silicone catheters, TA/Cu₂₅ (10 mM TA and 250 mM CuCl₂·2 H₂O) exhibited the highest antibacterial activity with killing ratios of 99.84%, 98.67%, 99.85%, and 99.90% against S. aureus, E. Coli, MRSA and VRE, respectively. Thus, the MPN has significant potential for developing antibacterial surface coatings for silicone catheters, which can effectively mitigate CAIs.