title: Surface tension and adsorption behavior of mixtures of diacyl glycerol arginine-based surfactants with DPPC and DMPC phospholipids.
abstract: The binary surface interactions of some novel cationic diacyl glycerol arginine-based surfactants with model phospholipids, which are often used as model membrane components, are studied at 25 degrees C in aqueous solutions of 0.1M sodium chloride. The surfactants are 1,2-dimyristoyl-rac-glycero-3-O-(N(alpha)-acetyl-L-arginine) hydrochloride (1414RAc) and 1,2-dilauroyl-rac-glycero-3-O-(N(alpha)-acetyl-L-arginine) hydrochloride (1212RAc), and they are important as potential antimicrobial agents which are biodegradable and with less toxicity than other cationic surfactants. The phospholipids are 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC). The equilibrium and dynamic surface tension of each surfactant, each phospholipid, and some of their binary mixtures are studied using the bubble surfactometry method at constant area or pulsating area conditions. In addition, the surface densities of pure and mixed monolayers of these compounds at the air/water interface are probed with infrared reflection-absorption spectroscopy (IRRAS). Steady state and dynamic surface tension synergism, or antisynergism in one case, and synergistic adsorption effects are detected for the mixed dispersions studied. The enhanced adsorption detected with IRRAS, and the enhanced dynamic and steady state surface tension lowering indicate strong miscibility and net attractive interactions between the compounds in the adsorbed mixed monolayers.
authors.affiliation: Departament de Tecnologia Química i de Tensioactius, Institut de Química Avançada de Catalunya (IQAC), CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Lozano
authors.forename: Aurora
authors.initials: A
authors.lastname: Pinazo
authors.forename: Ramon
authors.initials: R
authors.lastname: Pons
authors.forename: Lourdes
authors.initials: L
authors.lastname: Pérez
authors.forename: Elias I
authors.initials: EI
authors.lastname: Franses
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000327:Adsorption; D001120:Arginine / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry*; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D014732:Vibration
chemical_list: C545299:1,2-dilauroyl-glycero-3-O-(Nalpha-acetylarginine); C545298:1,2-dimyristoyl-glycero-3-O-(Nalpha-acetylarginine); D006020:Glycopeptides; D012996:Solutions; D013501:Surface-Active Agents; D015060:1,2-Dipalmitoylphosphatidylcholine; D001120:Arginine; D004134:Dimyristoylphosphatidylcholine