Arginine-based surfactants alter the rheological and in-plane structural properties of stratum corneum model membranes.

Hypothesis: Amino acid-based surfactants have been proposed as skin permeation enhancers. In this work, we investigated the potentiality of two arginine-based amphiphiles as permeation enhancers by studying their interaction with stratum corneum (SC) model lipid membranes.

Experiments: N-benzoyl arginine decyl- and dodecylamide were tested in comparison with the classical enhancer, oleic acid, and the non-enhancer, stearic acid.

Interaction of cationic surfactants with DPPC membranes: effect of a novel N-benzoylated arginine-based compound.

Cationic amino acid-based surfactants are known to interact with the lipid bilayer of microorganism resulting in cell death through a disruption of the membrane topology. To elucidate the interaction of a cationic surfactant synthesized in our lab, investigations involving N-benzoyl-arginine decyl amide (Bz-Arg-NHC), and model membranes composed by 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were done. Bz-Arg-NHCwas able to penetrate into DPPC monolayers up to a critical pressure of 59.

Bromide counterion as a spectroscopic sensor at the interface of cetyltrimethylammonium micelles.

The strong UV absorption of the bromide in aqueous solution undergoes a remarkable red shift of more than 10 nm induced by the addition of the salts that constitute a saline buffer. The maximum absorption wavelength of the bromide is displaced from approximately 194 nm in ultrapure water to wavelengths above 200 nm, depending on the composition of the solution. The bromide spectrum as counterion of the cetyltrimethylammonium in the surfactant CTAB also shows sensitivity to the aggregation behavior of the tensioactive, being able to detect intermolecular interactions even at concentrations lower than the critical micelle concentration.

Volume expansion of erythrocytes is not the only mechanism responsible for the protection by arginine-based surfactants against hypotonic hemolysis.

A novel arginine-based cationic surfactant N-benzoyl-arginine dodecylamide (Bz-Arg-NHC) was synthesized in our laboratory. In this paper we study the interaction of Bz-Arg-NHC with sheep and human red blood cells (SRBC and HRBC respectively) due to their different membrane physicochemical/biophysical properties. SRBC demonstrated to be slightly more resistant than HRBC to the hemolytic effect of the surfactant, being the micellar structure responsible for the hemolytic effect in both cases.