title: Rhythmic pore dynamics in a shrinking lipid vesicle.
abstract: The rhythmic motion of membrane pore behavior under nonequilibrium conditions was studied. Application of the surfactant triton X-100 (TX-100) caused lipid vesicles to exhibit two types of shrinking dynamics with pore generation, which depended on both the size of the vesicles and the concentration of added TX-100. Small vesicles and the addition of a low concentration of TX-100 resulted in rhythmic-pore dynamics, where a transient pore was generated within a vesicle in a repetitive manner. In contrast, large vesicles and a high concentration of TX-100 led to continuous-pore dynamics, where the vesicle maintained an open pore during the shrinking process. In the rhythmic-pore membrane, long-cycle oscillation was observed with large vesicles and a low concentration TX-100. The period of one cycle decreased with a decrease in the vesicle size and an increase in the TX-100 concentration. We discuss the mechanism of these trends by considering the elastic free energy of the membrane.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan. t-hamada@jaist.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hamada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Takao
authors.initials: T
authors.lastname: Ohta
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takagi
mesh_terms: D003198:Computer Simulation; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D008956:Models, Chemical; D017830:Octoxynol / Q000737:chemistry*; D009991:Oscillometry / Q000379:methods*; D010507:Periodicity; D016062:Porosity
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D017830:Octoxynol