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Updated: Jan 25, 2026
07:48
Rapid Encapsulation of Reconstituted Cytoskeleton Inside Giant Unilamellar Vesicles
Published on: November 10, 2021
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Giant Vesicles Encapsulating Aqueous Two-Phase Systems: From Phase Diagrams to Membrane Shape Transformations.
Yonggang Liu1, Reinhard Lipowsky2, Rumiana Dimova2
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
Frontiers in Chemistry
|April 27, 2019
Summary
Giant unilamellar vesicles encapsulating polymer solutions show phase separation. Membrane wetting and nanotube formation reveal insights into polymer-lipid interactions and spontaneous curvature.
Area of Science:
- Biophysics
- Materials Science
- Soft Matter Physics
Background:
- Giant unilamellar vesicles (GUVs) are crucial models for cell membranes.
- Aqueous two-phase systems (ATPS) formed by polymers like dextran and poly(ethylene glycol) (PEG) exhibit unique phase behavior.
- Understanding polymer-lipid interactions within confined environments is key to cellular processes.
Purpose of the Study:
- To review recent studies on GUVs containing dextran-PEG aqueous polymer solutions.
- To investigate the phase separation, interfacial tension, and membrane interactions of these systems.
- To explore how polymer phase behavior influences GUV morphology and membrane curvature.
Main Methods:
- Construction of ATPS phase diagrams using titration, density, and gel permeation chromatography.
- Measurement of ultralow interfacial tension near the critical point.
- Encapsulation of ATPS within GUVs, followed by osmotic deflation to induce morphological changes.
- Analysis of vesicle budding and nanotube formation to quantify spontaneous curvature.
Main Results:
- Dextran-PEG solutions exhibit phase separation above a critical concentration, with ultralow interfacial tension near the critical point.
- The scaling exponent of interfacial tension deviates from Ising universality due to polymer fractionation.
- Vesicle membrane wetting by polymer phases is controlled by polymer miscibility and lipid composition.
- Osmotic deflation induces vesicle budding and spontaneous membrane nanotube formation.
- Nanotube morphology provides quantitative estimates of spontaneous curvature driven by polymer adsorption.
Conclusions:
- Polymer phase separation within GUVs significantly impacts membrane morphology and dynamics.
- Asymmetric polymer adsorption onto lipid bilayers induces spontaneous curvature and nanotube formation.
- This work links macroscopic polymer phase behavior to microscopic membrane shape and interactions.
- The findings offer insights into membrane-shaping mechanisms and polymer-membrane recognition.
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