IFLYSIB   05383
INSTITUTO DE FISICA DE LIQUIDOS Y SISTEMAS BIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Antihemolysis induced by arginine-based surfactants
Autor/es:
M. ELISA FAIT; MELISA HERMET; FRANCESC COMELLES; PERE CLAPÉS; H. ARIEL ALVAREZ; EDUARDO PRIETO; SUSANA R. MORCELLE; LAURA BAKAS
Lugar:
Salto
Reunión:
Congreso; Latin American Crosstalk in Biophysics and Physiology; 2015
Institución organizadora:
Sociedad Argentina de Biofisica - Sociedad Uruguaya de Biociencias
Resumen:
Two novel arginine-based cationic surfactants (Bz-Arg-NHC10 and BzArg-NHC12) were synthesized in our laboratory using as biocatalystpapain, an endopeptidase from Carica papaya latex.The CMC, obtained from the intersection of the two linear portions in theplots γ vs C were 0.23 and 0.085 mM for Bz-Arg-NHC10 and Bz-ArgNHC12 respectively. Ionic surfactants have higher CMC values comparedto non-ionic ones due to the repulsion between the head groups However forBz-Arg-NHCn, the head group repulsion is counteracted by the additionalbenzoil group, facilitating the surfactant self assembly.We used in our experiments sheep (SRBC), and human (HBC) erythrocytesdue to their differences in protein and lipid composition. SRBC membraneslack of phosphatidylcholine (PC), which is substituted by sphingomyelin(SM). Both surfactants display a biphasic (protective/lytic) behavior uponinteraction with the erythrocytes membranes. The most accepted hypothesisfor the lytic action is that surfactants are intercalated into the lipid bilayer,leading to cell lysis. On the other hand, the antihemolytic mechanism isbased mainly on the idea that the intercalated compound increases either themembrane-area/cell-volume ratio or the stretching capacity of the bilayer,thereby allowing the cell to attain a higher critical hemolytic volume. HC50was found to be higher than the respective CMC, showing that hemolysis isinduced in the presence of aggregates rather than monomers. We found agood correlation between the CMC, HC50 and cAHmax for bothsurfactants. The lower CMC value correlates with the lower HC50 and thehigher cAHmax and pA (antihemolytic potency), i.e., the higher hemolyticactivity, the higher antihemolytic potency. Interestingly, HRBC showednegligible volume expansion caused by both surfactants, while a positivecorrelation was found on SRBC only for Bz-Arg-NHC12.This knowledge, together with a deeper study of the interaction propertiesof these compounds with skin would make the two novel argininecompounds a promising alternative to commercial cationic surfactants,especially for their use as penetration enhancers in topical formulations.