Biocompatible supramolecular systems based on novel cationic imidazolium- and urethane-containing amphiphiles: Self-assembly and antimicrobial properties

Abstract

In the framework of this investigation novel cationic amphiphiles of N-(2-butylaminocarbonyloxyethyl)-N-alkylimidazolium bromides series have been synthesized and characterized in terms of their aggregation capacity in aqueous solutions, antimicrobial properties and solubilization action toward hydrophobic dye. Using tensiometry, conductometry and fluorescence spectroscopy techniques it has been demonstrated, that the presence of urethane fragment with butyl moiety is responsible for the one order of magnitude decrease of critical micelle concentration of amphiphiles in comparison with unsubstituted analogs. Fabrication of aggregates with hydrodynamic diameter in the range of 4–10 nm has been exhibited for all amphiphiles. Transmission electron microscopy technique allows to establish the spherical shape of aggregates formed. These amphiphiles were shown as effective solubilizers of hydrophobic azodye, which efficacy could be 2.5-fold increased by elongation of the length of hydrophobic tail by four methylene units. Estimation of interaction of amphiphiles with biological objects has revealed, that all compounds exhibit high bacteriostatic and bactericide properties preferably toward gram-positive strains, as well as they have low hemolytic activity at active concentrations. Antibacterial properties of tetradecyl amphiphilic derivative have surpassed norfloxacin by 5 and 8.5 times in relation to Staphylococcus aureus and Bacillus cereus, respectively.