Specific wetting probed with biomimetic emulsion droplets

Fattaccioli, Jacques; Baudry, Jean; Henry, Nelly; Brochard‐Wyart, Françoise; Bibette, Jérôme

doi:10.1039/b806635c

Cited by 29 publications

(25 citation statements)

References 25 publications

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“…Emulsions are colloidal liquid-liquid metastable suspensions stabilized by a surfactant monolayer 45 that have already shown their biocompatibility and their interest as liquid probes in a biophysical context 46 47 . To fabricate the droplets, we manually shear soybean oil in an aqueous solution of a polymeric surfactant (poloxamer 188) to stabilize the emulsion and a viscosifier (sodium alginate) to increase the viscoelasticity of the continuous phase and ease the fragmentation.…”

Section: Resultsmentioning

confidence: 99%

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Molino

Quignard

Gruget³

et al. 2016

Sci Rep

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The ability of immune cells to migrate within narrow and crowded spaces is a critical feature involved in various physiological processes from immune response to metastasis. Several in-vitro techniques have been developed so far to study the behaviour of migrating cells, the most recent being based on the fabrication of microchannels within which cells move. To address the question of the mechanical stress a cell is able to produce during the encounter of an obstacle while migrating, we developed a hybrid microchip made of parallel PDMS channels in which oil droplets are sparsely distributed and serve as deformable obstacles. We thus show that cells strongly deform droplets while passing them. Then, we show that the microdevice can be used to study the influence of drugs on migration at the population level. Finally, we describe a quantitative analysis method of the droplet deformation that allows measuring in real-time the mechanical stress exerted by a single cell. The method presented herein thus constitutes a powerful analytical tool for cell migration studies under confinement.

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Section: Resultsmentioning

confidence: 99%

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Molino

Quignard

Gruget³

et al. 2016

Sci Rep

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“…Partial membrane adhesion for strong binding pairs like biotin-neutravidin has not been reported so far. 7,8,31 The experimental conditions used in these studies (i.e. the receptor concentration employed) favored strong, complete adhesion.…”

Section: Origin Of Partial Membrane Adhesionmentioning

confidence: 99%

Inter-membrane adhesion mediated by mobile linkers: Effect of receptor shortage

et al. 2011

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Giant unilamellar vesicles (GUVs) adhering to supported bilayers were used as a model system to mimic ligand-receptor mediated cell-cell adhesion. We present the effect of varying the concentration of receptors (neutravidin on the bilayer) and ligands (biotin on the vesicle) on GUV adhesion and the organization of receptors in the adhesion zone. At high concentrations of both ligands and receptors, the adhesion is strong, all the available membrane is adhered and receptors are accumulated under the adhered membrane up to the geometrical limit of close packing. At low concentrations of receptors (<0.5%), and an arbitrary concentration of ligands ($0.1%), adhesion does not proceed to completion: the membrane is only partially bound and parts of it still fluctuate. The receptors tend to accumulate under the adhered membrane but the filling is partial. Receptors get jammed and form clusters with fractal like shapes along the rim of the adhered vesicle in such a way that the annular cluster prevents further filling of the adhesion disc. We characterize the filling in terms of a compaction factor and the final concentration. Interestingly, the closing of the ring of jammed clusters switches the interior of the adhesion disc from one thermodynamic ensemble to another. In the new ensemble the receptors sealed within the adhesion disc are mobile but their number is fixed. Under such conditions, the usually strong neutravidin/biotin bond is weak. The incomplete adhesion state can be attributed to a combination of the effects of diffusion, jamming and the competition of enthalpy and entropy on bond formation. The formation of jammed receptor clusters reported here represents a new mechanism that influences membrane adhesion.

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“…By exploiting the well-characterized ligand-receptor pair biotin-streptavidin, EDs were immobilized on glass surfaces (9) and actively transported along microtubules (10). In the context of self-assembly, both polymer-mediated (11-13) and biotin-streptavidin-mediated aggregation of EDs was shown (14).…”

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confidence: 99%

Specific and reversible DNA-directed self-assembly of oil-in-water emulsion droplets

Hadorn

Boenzli

Sørensen

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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Higher-order structures that originate from the specific and reversible DNA-directed self-assembly of microscopic building blocks hold great promise for future technologies. Here, we functionalized biotinylated soft colloid oil-in-water emulsion droplets with biotinylated single-stranded DNA oligonucleotides using streptavidin as an intermediary linker. We show the components of this modular linking system to be stable and to induce sequencespecific aggregation of binary mixtures of emulsion droplets. Three length scales were thereby involved: nanoscale DNA base pairing linking microscopic building blocks resulted in macroscopic aggregates visible to the naked eye. The aggregation process was reversible by changing the temperature and electrolyte concentration and by the addition of competing oligonucleotides. The system was reset and reused by subsequent refunctionalization of the emulsion droplets. DNA-directed self-assembly of oil-in-water emulsion droplets, therefore, offers a solid basis for programmable and recyclable soft materials that undergo structural rearrangements on demand and that range in application from information technology to medicine.C omplex higher-order structures that spontaneously arise from the specific and reversible self-assembly of simple building blocks hold great promise to become the foundation of tomorrow's technology (1). In the context of DNA-directed self-assembly of hard colloids and artificial vesicles, linear DNA oligonucleotides were shown to be adhesive elements that allowed the self-assembly process not only to be specific but also to be reversible by a variety of external stimuli such as temperature (2-4), changes in the electrolyte concentration (4, 5), addition of competing oligonucleotides (6), and exploitation of the secondary structure of DNA oligonucleotides (7).Oil-in-water (o/w) emulsion droplets (EDs) offer a robust, configurable, and recyclable soft-colloid system with interesting properties for the fabrication of new delivery systems and advanced synthetic materials with adaptable properties (8). By exploiting the well-characterized ligand-receptor pair biotin-streptavidin, EDs were immobilized on glass surfaces (9) and actively transported along microtubules (10). In the context of self-assembly, both polymer-mediated (11-13) and biotin-streptavidin-mediated aggregation of EDs was shown (14). Despite the advantages a combination of EDs as building blocks and DNA oligonucleotides as linking agent offers, a protocol for DNA-directed self-assembly of EDs is currently missing.To close this gap, here we prepared an o/w emulsion composed of heavier-than-water diethyl phthalate (DEP) dispersed in an aqueous medium, stabilized by phospholipids, and functionalized with single-stranded DNA (ssDNA) oligonucleotides. Palmitoyloleoyl phosphatidylcholine (POPC) and distearoylphosphatidyl ethanolamine (DSPE) in a 9:1 molar ratio were used to stabilize the EDs. The DSPE was grafted with flexible poly(ethylene glycol) (PEG) tethers with a molecular weight of 2,000 (DSPE-PEG...

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Specific wetting probed with biomimetic emulsion droplets

Cited by 29 publications

References 25 publications

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

On-Chip Quantitative Measurement of Mechanical Stresses During Cell Migration with Emulsion Droplets

Inter-membrane adhesion mediated by mobile linkers: Effect of receptor shortage

Specific and reversible DNA-directed self-assembly of oil-in-water emulsion droplets

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