Pyrrolidinium surfactants with a biodegradable carbamate fragment: Self-assembling and biomedical application

Abstract

In this work, new carbamate-bearing surfactants of 1-alkyl-1-(2-(ethylcarbamoyloxy)ethyl) pyrrolidinium bromides (PRRC-n(Et)) series were obtained. The aggregation properties, antimicrobial activity, hemolytic action, ability to act as nanocontainers for hydrophobic substrates and their complexation effect toward human serum albumin (HSA) were investigated by a wide variety of physicochemical methods. Using tensiometry, conductometry and fluorescence spectroscopy it was shown that the modification of pyrrolidinium surfactants by a carbamate fragment allows to reduce the aggregation thresholds approximately twofold. For amphiphiles with 14, 16, 18 alkyl tails the formation of micellar aggregates was characteristic, while for surfactants with a dodecyl chain, a vesicle-micelle transition probably occurred. The study of the antimicrobial activity showed that all the amphiphiles studied exhibit high bacteriostatic and bactericidal action including activity against antibiotic resistant strains (MRSA) and high selectivity for microbial cells. Worth noting that at the same concentrations they had low hemolytic and cytotoxic activity. Also, the surfactants studied showed a high solubilizing capability toward a hydrophobic model dye Orange OT and an antifungal medicine - amphotericin B. Evaluation of the amphiphiles ability to interact with HSA using a hexadecyl derivative showed an atypical nature of the components binding due to electrostatic and hydrophobic interactions with the tyrosine fragment.