A biomimetic phage-inspired supramolecular system based on glucose-conjugated pillar[5]arene with ciprofloxacin...

Self-assembling phage-inspired carriers based on macrocyclic molecules have the potential to overcome antibiotic resistance and extend the antimicrobial effect of drugs. In this study, we have synthesized a new water-soluble pillar[5]arene containing thioglycoside fragments. This compound had an affinity for a model lipid membrane, underwent self-assembly, and associated with the fluoroquinolone antibiotic ciprofloxacin hydrochloride (Cipro) to form biocompatible supramolecular nanostructures. UV-vis and fluorescence spectroscopies were used to assess the ability of the pillar[5]arene/antibiotic system to form supramolecular complexes in a 1 : 2 stoichiometry (lg K_1 : 1 = 1.49 and lg K_1 : 2 = 4.22). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies confirmed the formation of stable pillararene/antibacterial complexes with particle sizes in the range of 250-300 nanometers. And the biological characteristics of the systems we obtained indicate their low toxicity to cancer (A549) and normal cells (LEK and HSF), with a twofold increase in the inhibitory effect of the combined pillar[5]arene/antibiotic system on the strain of K. pneumoniae with increased resistance to ciprofloxacin. The improved antibacterial properties of the antibiotic in combination with the pillar[5]arene may be due to the blocking of efflux pumps, which is confirmed by molecular docking.