title: Biomimetic lipid/polymer colorimetric membranes: molecular and cooperative properties.
abstract: Characterization of membranes and of biological processes occurring within membranes is essential for understanding fundamental cellular behavior. Here we present a detailed biophysical study of a recently developed colorimetric biomimetic membrane assembly constructed from physiological lipid molecules and conjugated polydiacetylene. Various analytical techniques have been applied to characterize the organization of the lipid components in the chromatic vesicles and their contributions to the observed blue-to-red color transitions. Experiments reveal that both the polymerized units as well as the lipids exhibit microscopic phases and form domains whose properties and bilayer organization are interdependent. These domains are interspersed within mixed lipid/polymer vesicles that have a size distribution different from those of aggregates of the individual molecular constituents. The finding that fluidity changes induced within the lipid domains are correlated with the chromatic transitions demonstrates that the colorimetric platform can be used to evaluate the effects of individual molecular components, such as negatively charged lipids and cholesterol, upon membrane fluidity and thermal stability.
authors.affiliation: Department of Chemistry and Stadler Minerva Center for Mesoscopic Macromolecular Engineering, Ben Gurion University of the Negev, Beersheva 84105, Israel.
authors.forename: Sofiya
authors.initials: S
authors.lastname: Kolusheva
authors.forename: Ellen
authors.initials: E
authors.lastname: Wachtel
authors.forename: Raz
authors.initials: R
authors.lastname: Jelinek
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry*; D032701:Biomimetics; D055592:Biophysical Phenomena; D001703:Biophysics; D002152:Calorimetry, Differential Scanning; D002308:Cardiolipins / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry; D003116:Color; D003124:Colorimetry / Q000379:methods*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000737:chemistry*; D010715:Phosphatidylglycerols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes; D013329:Structure-Activity Relationship
chemical_list: C434762:10,12-tricosadiynoic acid; D002308:Cardiolipins; D005231:Fatty Acids, Unsaturated; D008081:Liposomes; D008563:Membrane Lipids; D010715:Phosphatidylglycerols; D010743:Phospholipids; D000078789:Polyacetylene Polymer; D011108:Polymers; D053279:Polyynes; C082361:polydiacetylene; D002784:Cholesterol; C002773:dimyristoylphosphatidylglycerol; D000114:Acetylene; D004134:Dimyristoylphosphatidylcholine