title: Metastability in lipid based particles exhibits temporally deterministic and controllable behavior.
abstract: 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.
authors.affiliation: The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Jacoby
authors.affiliation: Laboratory of NanoMedicine, Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Department of Materials Sciences and Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
authors.forename: Keren
authors.initials: K
authors.lastname: Cohen
authors.affiliation: The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel.
authors.forename: Kobi
authors.initials: K
authors.lastname: Barkan
authors.affiliation: Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel.
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Talmon
authors.affiliation: Laboratory of NanoMedicine, Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Department of Materials Sciences and Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Peer
authors.affiliation: The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel.
authors.forename: Roy
authors.initials: R
authors.lastname: Beck
mesh_terms: D008055:Lipids / Q000737:chemistry*; D008956:Models, Chemical; D044367:Phase Transition
chemical_list: D008055:Lipids
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