Title : Emergence of Superstructures from a Homogeneous Lipid Sphere

Language: English
Type: Article
Authors: Makiko Negishi, Hiroyuki Kitahata and Kenichi Yoshikawa
Journal: Journal of Physical Chemistry B
Volume: 113
Number: 11
Month: 3
Year: 2009
Actual year: 2009
Pages: 3264-3268
doi:   10.1021/jp8113623
Abstract: The spontaneous generation of a periodic hexagonal superstructure on a giant phospholipid sphere (GPS) with a diameter of 20-200 mu m was studied. The GPS was composed of ternary phospholipids consisting of dioleoylphosphatidylethanolamine (DOPE), dioleoylphosphatidylcholine (DOPC), and dioleoylphosphatidyl-inositol-bisphosphate (DOPIP2). GPSs were prepared by natural swelling of a lipid film formed on a glass substrate. A GPS with a homogeneous lipid mixture tends to form a two-layered structure between the surface and inner parts; the surface layer is attributed to a DOPIP2 rich region (we call this layer SL), and the interior is rich in DOPE and DOPC (we call this layer IL). A hexagonal superstructure develops in the SL, and the topology then changes to form multiple-doughnut structures. Finally, myelin-like tubes are generated through symmetry breaking of the doughnutlike structures. The time-dependent change in the surface-area expansion of a GPS is shown to obey the logistic growth model, and this is attributed to the kinetic process of phase segregation between the surface and bulk phase of the GPS.

"Emergence of Superstructures from a Homogeneous Lipid Sphere"

Makiko Negishi, Hiroyuki Kitahata and Kenichi Yoshikawa, Journal of Physical Chemistry B, 113, 3264-3268, (2009)