title: Formation of lens-like vesicles induced via microphase separations on a sorbitan monoester membrane with different headgroups.
abstract: The microphase separation of lipid molecules on a vesicle membrane can be induced, depending on the difference in the geometric structures of their headgroups. Through cryo-transmission-electron-microscopy analysis, a lens-like vesicle was prepared by mixing 50 wt% Span 40 (sorbitan monopalmitate) and 50 wt% Tween 40 [polyoxyethylene (20) sorbitan monopalmitate]. Considering the molecular structures of Span 40 and Tween 40, the high-curvature region was mainly formed by Tween 40. As determined by Fourier-transform infrared spectroscopy, dielectric-dispersion analysis, and differential scanning calorimetry, a hydration layer was likely formed because polyoxyethylene conjugates with the headgroups of Tween 40. These investigations of the obtained self-assembled aggregates of nonionic surfactants with heterogeneous surfaces could contribute to the development of new types of biomaterials.
authors.affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.
authors.forename: Hideka
authors.initials: H
authors.lastname: Iwai
authors.affiliation: Department of Material and Energy Science, Graduate School of Environmental Science, Okayama University, 3-1-1 Tsushima-Naka, Okayama 700-8530, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Shimanouchi
authors.affiliation: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Umakoshi
authors.affiliation: Department of Bioscience, Integrated Center for Science Shigenobu Station, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Kato
authors.affiliation: Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan.
authors.forename: Hidemi
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D055664:Electrochemical Techniques; D006601:Hexoses / Q000737:chemistry; D006860:Hydrogen Bonding; D008055:Lipids / Q000302:isolation & purification; D008567:Membranes, Artificial; D011092:Polyethylene Glycols / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D006601:Hexoses; D008055:Lipids; D008567:Membranes, Artificial; D011136:Polysorbates; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; C061705:sorbitan monopalmitate
keywords: Nonionic-surfactant vesicle; Phase separation; Self-assembled aggregate