Novel ionic liquids with antibacterial and low cytotoxic properties for double-J stents

Infections are common postoperative complications associated with the use of medical implants such as ureteric double-J stents. However, bacterial resistance to antibiotics poses serious risks to human health. These complications highlight the need for novel antibacterial agents. This study aimed to synthesize ionic liquids (ILs) with antibacterial potential, namely, 1-benzyl-3-(2-nitrobenzoyl)-1 H-imidazol-3-ium chloride (OM-1) and 4-(dimethyl amino)-1-(4-nitrobenzoyl) pyridin-1-ium chloride (OM-2), for use as biocompatible coating materials on double-J stents. The chemical structures of the synthesized ILs were confirmed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The antibacterial properties were evaluated using the Kirby-Bauer Disk Diffusion method on Klebsiella pneumoniae and Escherichia coli. Cytotoxicity was evaluated in a human skin fibroblast cell line (HFF-1) using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H tetrazolium (MTS) assay. Molecular docking and ADMETox analyses were also performed to calculate binding affinities and pharmacokinetic properties. At 50 µg/mL, OM-1 and OM-2 exhibited significant activity against Klebsiella pneumoniae (p = 0.04), with OM-1 differing significantly from Gentamicin (p = 0.017). In Escherichia coli, both ILs exhibited significant differences compared to piperacillin/tazobactam (p < 0.001 and p = 0.002, respectively). At 100 µg/mL, both ILs demonstrated statistically significant differences compared to Ceftazidime and Piperacillin/Tazobactam. The IC₅₀ values for OM-1 and OM-2 in HFF-1 cells were calculated as 260.90 µg/mL and 216.35 µg/mL, respectively. Docking studies performed on OM-1 revealed stronger binding affinity as antifungal and antioxidant, while OM-2 was a stronger candidate for antibacterial applications due to its ADMETox profile. These findings, supported by both experimental and computational studies, confirm the biocoating potential of OM-1 and OM-2 for double-J stents.