Effects of lipid composition and solution conditions on the mechanical properties of membrane vesicles

Nobuhiko Kato, Akihiko Ishijima, Takehiko Inaba, Fumimasa Nomura, Shuichi Takeda, Kingo Takiguchi

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The mechanical properties of cell-sized giant unilamellar liposomes were studied by manipulating polystyrene beads encapsulated within the liposomes using double-beam laser tweezers. Mechanical forces were applied to the liposomes from within by moving the beads away from each other, which caused the liposomes to elongate. Subsequently, a tubular membrane projection was generated in the tip at either end of the liposome, or the bead moved out from the laser trap. The force required for liposome transformation reached maximum strength just before formation of the projection or the moving out of the bead. By employing this manipulation system, we investigated the effects of membrane lipid compositions and environment solutions on the mechanical properties. With increasing content of acidic phospholipids, such as phosphatidylglycerol or phosphatidic acid, a larger strength of force was required for the liposome transformation. Liposomes prepared with a synthetic dimyristoylphosphatidylcholine, which has uniform hydrocarbon chains, were transformed easily compared with liposomes prepared using natural phosphatidylcholine. Surprisingly, bovine serum albumin or fetuin (soluble proteins that do not bind to membranes) decreased liposomal membrane rigidity, whereas the same concentration of sucrose showed no particular effect. These results show that the mechanical properties of liposomes depend on their lipid composition and environment.

Original languageEnglish
Pages (from-to)22-47
Number of pages26
JournalMembranes
Volume5
Issue number1
DOIs
Publication statusPublished - 2015 Jan 20

Keywords

  • Biomechanical phenomena
  • Giant unilamellar liposome
  • Laser tweezers
  • Mechanical processes
  • Membrane vesicles
  • Real-time imaging

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Process Chemistry and Technology
  • Filtration and Separation

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