TY - JOUR
T1 - Metastability in lipid based particles exhibits temporally deterministic and controllable behavior
AU - Jacoby, Guy
AU - Cohen, Keren
AU - Barkan, Kobi
AU - Talmon, Yeshayahu
AU - Peer, Dan
AU - Beck, Roy
N1 - Funding Information:
R.B. acknowledges support by the Israeli Science Foundation (ISF 571/11), the European Community’s 7th Framework Programme (CIG - 293402) research grants and the Sackler Institute for Biophysics at Tel Aviv University. G.J. is supported by the Marian Gertner Institute for Medical Nanosystems. K.B. is supported by the Israel Science Foundation (ISF 556/10). Additional funding for this research was provided by Teva Pharmaceutical Industries Ltd. The TEM work was performed at the Technion Laboratory for Electron Microscopy of Soft Matter, supported by the Technion Russell Berrie Nanotechnology Institute (RBNI). We wish to thank P. Pincus, T. A. Witten, A. Parsegian, C. R. Safinya, W. Helfrich, H. Diamant, R. Lifshitz and M. Kozlov for enlightening discussions.
Publisher Copyright:
© 2015, Nature Publishing Group. All rights reserved.
PY - 2015/3
Y1 - 2015/3
N2 - The metastable-to-stable phase-transition is commonly observed in many fields of science, as an uncontrolled independent process, highly sensitive to microscopic fluctuations. In particular, self-assembled lipid suspensions exhibit phase-transitions, where the underlying driving mechanisms and dynamics are not well understood. Here we describe a study of the phase-transition dynamics of lipid-based particles, consisting of mixtures of dilauroylphosphatidylethanolamine (DLPE) and dilauroylphosphatidylglycerol (DLPG), exhibiting a metastable liquid crystalline-to-stable crystalline phase transition upon cooling from 60°C to 37°C. Surprisingly, unlike classically described metastable-to-stable phase transitions, the manner in which recrystallization is delayed by tens of hours is robust, predetermined and controllable. Our results show that the delay time can be manipulated by changing lipid stoichiometry, changing solvent salinity, adding an ionophore, or performing consecutive phase-transitions. Moreover, the delay time distribution indicates a deterministic nature. We suggest that the non-stochastic physical mechanism responsible for the delayed recrystallization involves several rate-affecting processes, resulting in a controllable, non-independent metastability. A qualitative model is proposed to describe the structural reorganization during the phase transition.
AB - The metastable-to-stable phase-transition is commonly observed in many fields of science, as an uncontrolled independent process, highly sensitive to microscopic fluctuations. In particular, self-assembled lipid suspensions exhibit phase-transitions, where the underlying driving mechanisms and dynamics are not well understood. Here we describe a study of the phase-transition dynamics of lipid-based particles, consisting of mixtures of dilauroylphosphatidylethanolamine (DLPE) and dilauroylphosphatidylglycerol (DLPG), exhibiting a metastable liquid crystalline-to-stable crystalline phase transition upon cooling from 60°C to 37°C. Surprisingly, unlike classically described metastable-to-stable phase transitions, the manner in which recrystallization is delayed by tens of hours is robust, predetermined and controllable. Our results show that the delay time can be manipulated by changing lipid stoichiometry, changing solvent salinity, adding an ionophore, or performing consecutive phase-transitions. Moreover, the delay time distribution indicates a deterministic nature. We suggest that the non-stochastic physical mechanism responsible for the delayed recrystallization involves several rate-affecting processes, resulting in a controllable, non-independent metastability. A qualitative model is proposed to describe the structural reorganization during the phase transition.
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U2 - 10.1038/srep09481
DO - 10.1038/srep09481
M3 - Article
C2 - 25820650
AN - SCOPUS:84926353677
VL - 5
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
M1 - 9481
ER -