title: Oleic acid disorders stratum corneum lipids in Langmuir monolayers.
abstract: Oleic acid (OA) is well-known to affect the function of the skin barrier. In this study, the molecular interactions between OA and model stratum corneum (SC) lipids consisting of ceramide, cholesterol, and palmitic acid (PA) were investigated with Langmuir monolayer and associated techniques. Mixtures with different OA/SC lipid compositions were spread at the air/water interface, and the phase behavior was tracked with surface pressure-molecular area (π-A) isotherms. With increasing OA levels in the monolayer, the films became more fluid and more compressible. The thermodynamic parameters derived from π-A isotherms indicated that there are preferential interactions between OA and SC lipids and that films of their mixtures were thermodynamically stable. The domain structure and lipid conformational order of the monolayers were studied through Brewster angle microscopy (BAM) and infrared reflection absorption spectroscopy (IRRAS), respectively. Results indicate that lower concentrations of OA preferentially mix with and disorder the ceramide-enriched domains, followed by perturbation of the PA-enriched domains and disruption of SC lipid domain separation at higher OA levels.
authors.affiliation: Johnson and Johnson Consumer Companies, Incorporated , 199 Grandview Road, Skillman, New Jersey 08558, United States. gmao@its.jnj.com
authors.forename: Guangru
authors.initials: G
authors.lastname: Mao
authors.forename: Dina
authors.initials: D
authors.lastname: VanWyck
authors.forename: Xin
authors.initials: X
authors.lastname: Xiao
authors.forename: M Catherine
authors.initials: MC
authors.lastname: Mack Correa
authors.forename: Euen
authors.initials: E
authors.lastname: Gunn
authors.forename: Carol R
authors.initials: CR
authors.lastname: Flach
authors.forename: Richard
authors.initials: R
authors.lastname: Mendelsohn
authors.forename: Russel M
authors.initials: RM
authors.lastname: Walters
mesh_terms: D000388:Air; D002518:Ceramides / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry*; D019308:Palmitic Acid / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D002518:Ceramides; D008055:Lipids; D014867:Water; D019301:Oleic Acid; D019308:Palmitic Acid; D002784:Cholesterol