scholarly journals Directed tubule growth from giant unilamellar vesicles in a thermal gradient

Soft Matter ◽  
2019 ◽  
Vol 15 (7) ◽  
pp. 1676-1683 ◽  
Author(s):  
Emma L. Talbot ◽  
Jurij Kotar ◽  
Lorenzo Di Michele ◽  
Pietro Cicuta
Keyword(s):  
Liquid Phase ◽  
Thermal Gradient ◽  
Phase Coexistence ◽  
Lipid Phase ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Experimental Control

We demonstrate experimental control over tubule growth in giant unilamellar vesicles with liquid–liquid phase coexistence, using a thermal gradient to redistribute lipid phase domains on the membrane.

Accurate quantification of inter-domain partition coefficients in GUVs exhibiting lipid phase coexistence

RSC Advances ◽  
2016 ◽  
Vol 6 (71) ◽  
pp. 66641-66649 ◽  
Author(s):  
M. J. Sarmento ◽  
S. N. Pinto ◽  
A. Coutinho ◽  
M. Prieto ◽  
F. Fernandes
Keyword(s):  
Partition Coefficients ◽  
Phase Coexistence ◽  
Lipid Phase ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Domain Partition ◽  
Fluorescent Molecules ◽  
Accurate Quantification

Giant unilamellar vesicles (GUVs) with phase coexistence allow for the recovery of inter-domain partition coefficients (Kp) of fluorescent molecules through comparison of fluorescence intensities in each phase.

Fluorescent probe partitioning in giant unilamellar vesicles of ‘lipid raft’ mixtures

2010 ◽  
Vol 430 (3) ◽  
pp. 415-423 ◽  
Author(s):  
Janos Juhasz ◽  
James H. Davis ◽  
Frances J. Sharom
Keyword(s):  
Fluorescent Probe ◽  
Lipid Bilayer ◽  
Fluorescent Probes ◽  
Phase Behaviour ◽  
Model Systems ◽  
Fluorescence Probes ◽  
Lipid Phase ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Lipid Mixture

Direct visualization of raft-like lo (liquid-ordered) domains in model systems and cells using microscopic techniques requires fluorescence probes with known partitioning preference for one of the phases present. However, fluorescent probes may display dissimilar partitioning preferences in different lipid sys-tems and can also affect the phase behaviour of the host lipid bilayer. Therefore a detailed understanding of the behaviour of fluorescent probes in defined lipid bilayer systems with known phase behaviour is essential before they can be used for identifying domain phase states. Using giant unilamellar vesicles composed of the ternary lipid mixture DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine)/DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine)/cholesterol, for which the phase behaviour is known, we examined nine commonly used fluorescent probes using confocal fluorescence microscopy. The partitioning preference of each probe was assigned either on the basis of quantification of the domain area fractions or by using a well-characterized ld (liquid-disordered)-phase marker. Fluorescent probes were examined both individually and using dual or triple labelling approaches. Most of the probes partitioned individually into the ld phase, whereas only NAP (naphtho[2,3-a]pyrene) and NBD-DPPE [1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl] preferred the lo phase. We found that Rh-DPPE (Lissamine™ rhodamine B–1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine) increased the miscibility transition temperature, Tmix. Interestingly, the partitioning of DiIC18 (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate) was influenced by Bodipy®-PC [2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-1-hexa-decanoyl-sn-glycero-3-phosphocholine]. The specific use of each of the fluorescent probes is determined by its photostability, partitioning preference, ability to detect lipid phase separations and induced change in Tmix. We demonstrate the importance of testing a specific fluorescent probe in a given model membrane system, rather than assuming that it labels a particular lipid phase.

scholarly journals Giant unilamellar vesicles - a perfect tool to visualize phase separation and lipid rafts in model systems.

2009 ◽  
Vol 56 (1) ◽  
Author(s):  
Olga Wesołowska ◽  
Krystyna Michalak ◽  
Jadwiga Maniewska ◽  
Andrzej B Hendrich
Keyword(s):  
Phase Separation ◽  
Lipid Membranes ◽  
Average Diameter ◽  
Model Systems ◽  
Membrane Properties ◽  
Lipid Phase ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Simple Method ◽  
Wide Range

Model systems such as black lipid membranes or conventional uni- or multilamellar liposomes are commonly used to study membrane properties and structure. However, the construction and dimensions of these models excluded their direct optical microscopic observation. Since the introduction of the simple method of liposome electroformation in alternating electric field giant unilamellar vesicles (GUVs) have become an important model imitating biological membranes. Due to the average diameter of GUVs reaching up to 100 microm, they can be easily observed under a fluorescent or confocal microscope provided that the appropriate fluorescent probe was incorporated into the lipid phase during vesicle formation. GUVs can be formed from different lipid mixtures and they are stable in a wide range of physical conditions such as pH, pressure or temperature. This mini-review presents information about the methods of GUV production and their usage. Particularly, the use of GUVs in studying lipid phase separation and the appearance and behavior of lipid domains (rafts) in membranes is discussed but also other examples of GUVs use in membrane research are given. The experience of the authors in setting up the GUV-forming equipment and production of GUVs is also presented.

scholarly journals Lipid phase separation in the presence of hydrocarbons in giant unilamellar vesicles

2017 ◽  
Vol 4 (4) ◽  
pp. 528-542 ◽  
Author(s):  
Rianne Bartelds ◽  
◽  
Jonathan Barnoud ◽  
Arnold J. Boersma ◽  
Siewert J. Marrink ◽  
...  
Keyword(s):  
Phase Separation ◽  
Lipid Phase ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Lipid Phase Separation

scholarly journals Effect of the Membrane Composition of Giant Unilamellar Vesicles on Their Budding Probability: A Trade-Off between Elasticity and Preferred Area Difference

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 634
Author(s):  
Ylenia Miele ◽  
Gábor Holló ◽  
István Lagzi ◽  
Federico Rossi
Keyword(s):  
Phospholipid Fatty Acid ◽  
Enzymatic Reaction ◽  
Stimuli Responsive ◽  
Membrane Composition ◽  
Giant Unilamellar Vesicles ◽  
Physical Processes ◽  
Unilamellar Vesicles ◽  
Division Process ◽  
The Origin Of Life ◽  
Area Difference

The budding and division of artificial cells engineered from vesicles and droplets have gained much attention in the past few decades due to an increased interest in designing stimuli-responsive synthetic systems. Proper control of the division process is one of the main challenges in the field of synthetic biology and, especially in the context of the origin of life studies, it would be helpful to look for the simplest chemical and physical processes likely at play in prebiotic conditions. Here we show that pH-sensitive giant unilamellar vesicles composed of mixed phospholipid/fatty acid membranes undergo a budding process, internally fuelled by the urea–urease enzymatic reaction, only for a given range of the membrane composition. A gentle interplay between the effects of the membrane composition on the elasticity and the preferred area difference of the bilayer is responsible for the existence of a narrow range of membrane composition yielding a high probability for budding of the vesicles.

Domain Sorting in Giant Unilamellar Vesicles Adsorbed on Glass

Langmuir ◽  
2021 ◽  
Vol 37 (3) ◽  
pp. 1082-1088
Author(s):  
Chiho Kataoka-Hamai ◽  
Kohsaku Kawakami
Keyword(s):  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles

scholarly journals Production of giant unilamellar vesicles and encapsulation of lyotropic nematic liquid crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Peng Bao ◽  
Daniel A. Paterson ◽  
Sally A. Peyman ◽  
J. Cliff Jones ◽  
Jonathan A. T. Sandoe ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Double Emulsion ◽  
Lyotropic Liquid Crystals ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Emulsion Droplets ◽  
Double Emulsion Droplets

We describe a modified microfluidic method for making Giant Unilamellar Vesicles (GUVs) via water/octanol-lipid/water double emulsion droplets and encapsulation of nematic lyotropic liquid crystals (LNLCs).

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