MICELLAR ATTACK OF ARGININE-BASED SURFACTANTS TOWARDS THE ERYTHROCYTE MEMBRANE

COMELLES, F.; PRIETO, E.; FAIT, M.E.; CLAPÉS, P.; MORCELLE, S. R.; HERMET, M.; ALVAREZ, A.; BAKÁS, L.

Tucumán

Congreso; III LAFeBS-IX Iberoamerican Congress of Biophysics-XLV reunión de la SAB; 2016

Arginine-based surfactants constitute an interesting group of amino acid-based surfactants since they are generally non-toxic and highly biodegradable cationic compounds .Two novel arginine-based compounds, Bz-Arg-NHC10 and Bz-Arg-NHC12, were characterized in terms of surface properties and interaction with human red blood cells (HRBC) membranes. The CMC values, obtained by surface tension determinations, were 0.23 mM for Bz-Arg-NHC10 and 0.085 mM for Bz-Arg-NHC12. According to the Γmax (maximum surfactant adsorption at the air/liquid interface) and Amin (area per molecule) values calculated for both compounds, Bz-Arg-NHC12 showed better surface properties than Bz-Arg-NHC10. Cylindrical worm-like aggregates were observed in atomic force microscopy (AFM) images for Bz-Arg-NHCn supported the predictions based on the surfactant packing parameter value (SPP). Hemolytic effect of Bz-Ar-NHCn on HRBC at different hematocrits allowed the determination of the effective surfactant/lipid molar ratios for saturation (Rsat), being these ratios of 6 molecules of Bz-Arg-NHC12 and 11 molecules of Bz-Arg-NHC10 per lipid molecule. Erythrocyte membrane solubilization was induced by surfactant aggregates, since cell lysis was only evidenced at surfactant concentrations above CMC. Changes in HRBC shape observed at different surfactants? concentrations allowed to conclude that a slow micellar mechanism, based on the extraction of membrane lipids upon collisions between HRBC and surfactant aggregates or by shedding of microvesicles would be responsible for the hemolysis produced by both surfactants.