Spontaneous Generation of Giant Liposomes from an Oil/Water Interface

Yamada, Ayako; Berre, Maël Le; Yoshikawa, Kenichi; Baigl, Damien

doi:10.1002/cbic.200700473

Cited by 19 publications

(15 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to their biomimetic properties, GUVs have particular utility for the study of lateral lipid heterogeneities, 1 membrane budding and fusion, 2,3 and in the construction of protocells. 4 Several methods are employed for GUV formation including electroformation, 5,6 gentle hydration, 7,8 interdigitation-fusion, 9 emulsion-based methods, 10,11 and more recently using microfluidic devices. 12,13 These methods generate GUVs, but have a limited scope for variations in lipid composition and ionic strength conditions, or they require special equipment and microfabrication expertise.…”

mentioning

confidence: 99%

Formation of giant unilamellar vesicles from spin-coated lipid films by localized IR heating

et al. 2012

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

Formation of giant unilamellar vesicles from spin-coated lipid films by localized IR heating

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The electrochemical reduction of giant unilamellar vesicles (GUVs) essentially tagged on their outerl eafletsw ith NBD (7nitrobenz-2-oxa-1,3-diazole), used as am odel redox fluorescent probe,w as first investigated.A ccordingly,afirst series of GUVs made of 1,2-dioleoyl-sn-glycero-3-phosphoglycerol (DOPG) phospholipids, aclassical anionic phospholipid used to prepare endosome models, and of as mall fraction( 5mol %) of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3benzoxadiazol-4-yl) (NBD-PE) was prepared. The preparation method for such asymmetrical liposomes was inspired by the works reported by Weitz, [34] Baigl, [35] and Ces [36] who developed protocols to generate giant liposomes from an oil/water interface. Briefly,l ipid-coated water/sucrose-in-oil (W/O) droplets (destined for the inner leaflet) were passed through an oilwater/glucose( O/W) column with an interfacial monolayer of lipids to form the vesicle outer leaflet.…”

Section: Resultsmentioning

confidence: 99%

“…Actually,asmall fraction of fluorescent phospholipids may have been incorporated in the outer leaflet of the vesicle during their preparation. [34,35] Conversely,asignificant fluorescence intensity decrease was observed in the case of outerleaflet NBD-labeled vesicles. Almost 80 %o ft he fluorescence was indeed quenched after 600 seconds of electrochemical reduction/bleaching.…”

Section: Discrimination Betweent He Outer and The Inner Membrane Leafmentioning

confidence: 94%

Selective Electrochemical Bleaching of the Outer Leaflet of Fluorescently Labeled Giant Liposomes

Jimenez

Challier

Delacotte

et al. 2017

Chemistry A European J

View full text Add to dashboard Cite

Electrochemistry and confocal fluorescence microscopy were successfully combined to selectively bleach and monitor the fluorescence of NBD (7-nitrobenz-2-oxa-1,3-diazole)-labeled phospholipids of giant liposomes. Three types of giant unilamellar vesicles have been investigated, the fluorescent phospholipids being localized either mainly on their outer-, inner-, or both inner/outer leaflets. We established that only the fluorescent lipids incorporated in the outer leaflet of the vesicles underwent electrochemical bleaching upon reduction. The relative fluorescence intensity decay was quantified all along the electrochemical extinction through an original fluorescence loss in electrobleaching (FLIE) assay. As expected, the reorganization of the fluorescent phospholipids followed diffusion-driven dynamics. This was also evidenced by comparison with fluorescence loss in photobleaching (FLIP) and the corresponding numerical model. The value of the lateral diffusion coefficient of phospholipids was found to be similar to that obtained by other methods reported in the literature. This versatile and selective bleaching procedure appears reliable to explore important biological and pharmacological issues.

show abstract

“…So to investigate wall effects and the effectiveness of rotational particle tracking microrheology inside cells, Zhang et al [4] replaced the real cell with artificial unilamellar lipid vesicles, known as liposomes, to serve as a simple model of a cell. The Liposomes were prepared following a protocol described in Yamada et al [96] that was modified so that the liposomes encapsulated vaterite particles. Zhang et al present direct measurements of constrained rotational motion of optically spun particles inside the liposomes and show how the rotational motion changes close to the membrane.…”

Section: Comparison With Experimentsmentioning

confidence: 99%

Hydrodynamic forces in optical tweezers

Gibson¹

View full text Add to dashboard Cite

Optical tweezers uses light to control and trap microscopic entities including spherical particles, cells or even three dimensionally (3D) printed structures. In most cases the trapped microscopic object is surrounded by a fluid, such as water, and the effects of hydrodynamic forces are significant. This dissertation investigates three aspects of these hydrodynamic forces relevant to optical tweezers systems. The first aspect is about how hydrodynamic forces in optical tweezers could be used to measure the medium's viscosity and elasticity (viscoelasticity). Previous methods of measuring viscoelasticity using optical tweezers have been limited by their several-minute measurement duration, making them unreliable in biological systems that are slowly changing. To solve this problem new theory and analysis is introduced, experimentally verified by Shu Zhang et al. [1, 2] , that enables optical tweezers to perform highly localised measurements of viscoelasticity in sub-minute times. The second part of the project investigates the hydrodynamic interactions between trapped particles and nearby boundaries. Both numerical and analytical techniques, including novel solutions to the Stokes equations, are presented and used to model the fluid dynamics. The effects of spherical and cylindrical boundaries on an internal sphere are quantified theoretically and compared to experimentally measured (by Shu Zhang et al. [3, 4]) wall effects of a 3D printed cylinder based on 2 photon photopolymerisation and round artificial liposomes on the rotation of an optically trapped sphere. An artificial feed-forward neural network is also trained to efficiently reproduce some of these results. The third part of the project relates to hydrodynamic forces acting on non-spherical star-shaped particles. Calculating drag tensors describing this geometry using existing methods is relatively slow (∼ 10 0 s). Using these slower numerical methods, the drag tensors of many randomly generated particles are computed and then train an artificial feed-forward neural network to improve the speed (∼ 10 −4 s) at which these drag tensors could be evaluated, making them practical for simulations or real time calculations. By improving existing techniques and quantifying these kinds of hydrodynamic forces, this work allows optical tweezers to be better applied in microfluidic or biological systems, such as inside a cell, and allows more accurate or more efficient optical tweezers simulations.

show abstract

Spontaneous Generation of Giant Liposomes from an Oil/Water Interface

Cited by 19 publications

References 55 publications

Formation of giant unilamellar vesicles from spin-coated lipid films by localized IR heating

Formation of giant unilamellar vesicles from spin-coated lipid films by localized IR heating

Selective Electrochemical Bleaching of the Outer Leaflet of Fluorescently Labeled Giant Liposomes

Hydrodynamic forces in optical tweezers

Contact Info

Product

Resources

About