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

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 Escherichia coli (E. coli) 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. In vitro and in vivo investigations showed that the PFDT-Ag-Dex coated Si catheter significantly inhibited the E. coli 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, in vivo 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.