title: Spontaneous nematic alignment of a lipid nanotube in aqueous solutions.
abstract: The dispersibility and liquid crystal formation of a self-assembled lipid nanotube (LNT) was investigated in a variety of aqueous solutions. As the lipid component, we chose a bipolar lipid with glucose and tetraglycine headgroups, which self-assembled into an LNT with a small outer diameter of 16 to 17 nm and a high axial ratio of more than 310. The LNT gave a stable colloidal dispersion in its dilute solutions and showed spontaneous liquid crystal (LC) alignment at relatively low concentrations and in a pH region including neutral pH. The LNT samples with shorter length distributions were prepared by sonication, and the relationship between the LNT axial ratio and the minimum LC formation concentration was examined. The robustness of the LNT made the liquid crystal stable in mixed solvents of water/ethanol, water/acetone, and water/tetrahydrofuran (1:1 by volume) and at a temperature of up to 90 °C in water. The observed colloidal behavior of the LNT was compared to those of similar 1D nanostructures such as a phospholipid tubule.
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Wuxiao
authors.initials: W
authors.lastname: Ding
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Minamikawa
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kameta
authors.forename: Momoyo
authors.initials: M
authors.lastname: Wada
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Masuda
authors.forename: Toshimi
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D003102:Colloids; D004537:Eicosanoic Acids / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D050866:Liquid Crystals / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013010:Sonication; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D004537:Eicosanoic Acids; D009842:Oligopeptides; D012996:Solutions; D012997:Solvents; D014867:Water; D005947:Glucose; C046274:glycyl-glycyl-glycyl-glycine