title: Continuity of Monolayer-Bilayer Junctions for Localization of Lipid Raft Microdomains in Model Membranes.
abstract: We show that the selective localization of cholesterol-rich domains and associated ganglioside receptors prefer to occur in the monolayer across continuous monolayer-bilayer junctions (MBJs) in supported lipid membranes. For the MBJs, glass substrates were patterned with poly(dimethylsiloxane) (PDMS) oligomers by thermally-assisted contact printing, leaving behind 3 nm-thick PDMS patterns. The hydrophobicity of the transferred PDMS patterns was precisely tuned by the stamping temperature. Lipid monolayers were formed on the PDMS patterned surface while lipid bilayers were on the bare glass surface. Due to the continuity of the lipid membranes over the MBJs, essentially free diffusion of lipids was allowed between the monolayer on the PDMS surface and the upper leaflet of the bilayer on the glass substrate. The preferential localization of sphingomyelin, ganglioside GM1 and cholesterol in the monolayer region enabled to develop raft microdomains through coarsening of nanorafts. Our methodology provides a simple and effective scheme of non-disruptive manipulation of the chemical landscape associated with lipid phase separations, which leads to more sophisticated applications in biosensors and as cell culture substrates.
authors.affiliation: School of Electrical Engineering #032, Seoul National University, Kwanak P.O. Box 34, Seoul 151-600 Korea.
authors.forename: Yong-Sang
authors.initials: YS
authors.lastname: Ryu
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Wittenberg
authors.affiliation: School of Electrical Engineering #032, Seoul National University, Kwanak P.O. Box 34, Seoul 151-600 Korea.
authors.forename: Jeng-Hun
authors.initials: JH
authors.lastname: Suh
authors.affiliation: School of Electrical Engineering #032, Seoul National University, Kwanak P.O. Box 34, Seoul 151-600 Korea.
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Anatomy, College of Korean Medicine, Institute of Oriental Medicine, Kyung Hee University, Seoul 130-701, Korea.
authors.forename: Youngjoo
authors.initials: Y
authors.lastname: Sohn
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.|Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Oh
authors.affiliation: Departments of Biomedical Engineering and Chemical Engineering &Materials Science, University of California, Davis, California 95616, USA.
authors.forename: Atul N
authors.initials: AN
authors.lastname: Parikh
authors.affiliation: School of Electrical Engineering #032, Seoul National University, Kwanak P.O. Box 34, Seoul 151-600 Korea.
authors.forename: Sin-Doo
authors.initials: SD
authors.lastname: Lee
mesh_terms: D002772:Cholera Toxin / Q000493:pharmacokinetics; D002784:Cholesterol / Q000737:chemistry; D005677:G(M1) Ganglioside / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D021962:Membrane Microdomains / Q000737:chemistry*; D008954:Models, Biological; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism; D013109:Sphingomyelins / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D011956:Receptors, Cell Surface; D013109:Sphingomyelins; C034993:ganglioside receptor; D005677:G(M1) Ganglioside; D002772:Cholera Toxin; D002784:Cholesterol