title: Preparation of J-aggregate liposome dispersions and their chromic transformation.
abstract: We report the preparation of aqueous liposome dispersions of J-aggregates formed by the amphiphilic merocyanine dye (MD). A series of liposome-forming lipids were dispersed together with MD J-aggregates at different molar ratios of MD to lipid. The MD J-aggregate dispersions prepared with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at the MD to DMPC ratio of 0.16 exhibit good dispersibility; that is, they can be readily redispersed without any flocculation even after their precipitation. By use of different counterions for the MD molecules, two types of J-aggregate dispersions, one that exhibits an absorption band (J-band) at 635 nm (type I) and the other at 600 nm (type II), were obtained. As an example of the use of MD J-aggregates liposome dispersions, the thermochromic transformation of MD J-aggregates was demonstrated. When the dispersions are heated, J-aggregates of type I transformed into type II at a certain temperature (T(disp)). The parameters that control the speed of the transformation and the value of T(disp) were determined.
authors.affiliation: Centre for Nanoscience and Nanotechnology, Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia. n.k@waseda.jp
authors.forename: Noritaka
authors.initials: N
authors.lastname: Kato
authors.forename: Jennifer
authors.initials: J
authors.lastname: Prime
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Katagiri
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008055:Lipids / Q000138:chemical synthesis* / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011744:Pyrimidinones / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D002413:Cations, Divalent; D008055:Lipids; D008081:Liposomes; D011744:Pyrimidinones; D014867:Water; C003954:merocyanine dye; D004134:Dimyristoylphosphatidylcholine