MICELLAR ATTACK OF ARGININE-BASED SURFACTANTS TOWARDS THE ERYTHROCYTE MEMBRANE

ELISA FAIT; MELISA HERMET; FRANCESC COMELLES; PERE CLAPÉS; HUGO ARIEL ALVAREZ; BIOQ. PRIETO E.D; SUSANA MORCELLE; LAURA BAKAS

San Carlos de Bariloche

Congreso; III Latin American Federation of Biophysical Societies (LAFeBS). IX IberoAmerican Congress of Biophysics . XLV Reunion Anual SAB; 2016

Sociedad Argentina de Biofisica

Arginine-based surfactants constitute an interesting group of aminoacid-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 interms of surface properties and interaction with human red blood cells(HRBC) membranes. The CMC values, obtained by surface tensiondeterminations, were 0.23 mM for Bz-Arg-NHC10 and 0.085 mM forBz-Arg-NHC12. According to theGammamax (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-ArgNHC10.Cylindrical worm-like aggregates were observed in atomicforce microscopy (AFM) images for Bz-Arg-NHCn supported thepredictions based on the surfactant packing parameter value (SPP).Hemolytic effect of Bz-Ar-NHCn on HRBC at different hematocrits allowedthe determination of the effective surfactant/lipid molar ratios forsaturation (Rsat), being these ratios of 6 molecules of Bz-Arg-NHC12and 11 molecules of Bz-Arg-NHC10 per lipid molecule. Erythrocytemembrane solubilization was induced by surfactant aggregates, sincecell lysis was only evidenced at surfactant concentrations above CMC.Changes in HRBC shape observed at different surfactants? concentrationsallowed to conclude that a slow micellar mechanism, based on theextraction of membrane lipids upon collisions between HRBC and surfactantaggregates or by shedding of microvesicles would be responsiblefor the hemolysis produced by both surfactants.