Hierarchical silver-tannic acid hydrophobic coating via layer-by-layer assembly for antibiofilm applications on urinary catheters

Catheter-associated urinary tract infections (CAUTIs) are a serious global concern due to the emergence of drug-resistant bacteria and the biofilm formation on urinary catheters (UCs). Surface modification strategies have been identified as a prominent and cost-effective method to address this issue owing to its tunable properties, which effectively combat the biofilm formation on UCs. This study reports the development of a hydrophobic-silver nanoparticles (Ag NPs) decorated tannic acid-based coating on silicone UC using a layer-by-layer (LBL) approach that can effectively eradicate <i>Escherichia coli</i> (<i>E. coli</i>) biofilms. The LBL coating (PFDT-Ag-Dex) consists of a tannic acid (TA)-(3-aminoprophyl) triethoxysilane (APTES) NPs deposition, followed by Ag NPs decoration and 1H,1H,2H,2H-perfluorodecane-thiol (PFDT) layers, which impart the hydrophobicity, biocompatibility, antibacterial activity, and coating adhesion, respectively. Formation of the LBL coating on the Si catheter was successfully confirmed through extensive characterizations. <i>In vitro</i> and <i>in vivo</i> investigations showed that the PFDT-Ag-Dex coated Si catheter significantly inhibited the <i>E. coli</i> biofilm formation with ∼95 % efficiency due to the combined effects of the hydrophobic properties, tannic acid and Ag⁺ ions causing the cell membrane disruption. Furthermore, <i>in vivo</i> studies using mouse and rabbit animal models confirmed the biosafety of the PFDT-Ag-Dex-coated Si catheter, which exhibited a negligible inflammatory response. The studies suggest that the Ag-TA-hydrophobic coated catheter is a promising solution for combating the urinary tract infections.