Spontaneously Formed Unilamellar Vesicles with Path-Dependent Size Distribution Academic Article uri icon

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  • We observe the spontaneous formation of path-dependent monodisperse and polydisperse phospholipid unilamellar vesicles (ULV) from two different equilibrium morphologies specifically, disklike micelles and extended lamellae, respectively. On heating beyond a temperature Tc, low temperature disklike micelles, or so-called bicelles, transform into lamellae. Dilution of the lamellar phase, at a fixed temperature, results in a complete unbinding transition and the formation of polydisperse ULV, demonstrating the instability of the lamellar phase. On the other hand, heating of a dilute bicellar phase above Tc results in monodisperse ULV, which on cooling revert back to bicelles for lipid concentrations phi > or = 0.5 wt % and transform into oblate ellipsoids for phi = 0.1 wt %, a morphology not previously seen in "bicellar" lipid mixtures. Monodisperse ULV reform on heating of the oblate ellipsoids.


  • Nieh, Mu-Ping
  • Raghunathan, Velayudhan A
  • Kline, Steve R
  • Harroun, Thad A
  • Huang, Chien-Yueh
  • Pencer, Jeremy
  • Katsaras, John

publication date

  • July 1, 2005