Miho Yanagisawa

We report an experimental study on shape deformations of ternary vesicles undergoing phase separation under an osmotic pressure difference. The phase separation on various shape vesicles causes unique shape-deformation branches. In the domain coarsening stage, prolate, discocyte, and starfish vesicles show a shape convergence to discocytes, whereas a pearling instability is observed in tube vesicles. In late stages, the domains start to bud towards the inside or outside of the vesicle depending

We report a method for the successful reconstitution of the KcsA potassium channel with either an outside-out or inside-out orientation in giant unilamellar vesicles, using the droplet-transfer technique. The procedure is rather simple. First, we prepared water-in-oil droplets lined with a lipid monolayer. When solubilized KcsA was encapsulated in the droplet, it accumulated at monolayers of phosphatidylglycerol (PG) and phosphoethanolamine (PE) but not at a monolayer of phosphatidylcholine (PC)

We report the spontaneous patterning of polymer microgels by confining a polymer blend within microspheres. A poly(ethylene glycol) (PEG) and gelatin solution was confined inside water-in-oil (W/O) microdroplets coated with a layer of zwitterionic lipids: dioleoylphosphatidylethanolamine (PE) and dioleoylphosphatidylcholine (PC). The droplet confinement affected the kinetics of the phase separation, wetting, and gelation after a temperature quench, which determined the final microgel pattern. Th

Even though microgels are used in a wide variety of applications, determining their mechanical properties has been elusive because of the difficulties in analysis. In this study, we investigated the surface elasticity of a spherical microgel of gelatin prepared inside a lipid droplet by using micropipet aspiration. We found that gelation inside a microdroplet covered with lipid membranes increased Young's modulus <i>E</i> toward a plateau value <i>E</i>* along with a decrease in gel size. In the

We created pairs of adhering water-in-oil microdroplets coated with lipid monolayers as model cells and studied the effects of the physicochemical properties of the lipids on the adhesive force ΔF. Four species of liquid-phase lipids were used: dioleoylphosphatidylethanolamine (DOPE), dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC), and dimyristoylphosphatidylcholine (DMPC). The dependence of ΔF on the choice of lipid was evaluated by independently measuring the interfa

Titania pillared H 4 Nb 6 O 17 has been synthesised by the intercalation of [Ti(OH) x (CH 3 CO 2 ) y ] z+ followed by photodecomposition with UV light irradiation. The incorporation of TiO 2 in the interlayer of H 4 Nb 6 O 17 has been confirmed by powder X-ray diffraction, DTA, UV-VIS reflectance and BET measurements. The incorporation of TiO 2 in the interlayer of H 4 Nb 6 O 17 results in enhanced water cleavage by band gap irradiation. The photocatalytic activity of TiO 2 pillared H 4 Nb 6 O 1

We investigated changes in the shape of tubular ternary vesicles induced by phase separation into liquid-ordered and liquid-disordered phases. Tubular vesicles transform into two types of periodically modulated vesicles depending on the area fraction of the liquid-ordered phase. One type is a necklace of oblate subunits with two circular domains of the liquid-order phase, and the other is a periodically modulated tube with stripes of the liquid-order phase. The transition between the circular an

Within living cells, a diverse array of biomolecules is present at high concentrations. To better understand how molecular behavior differs under such conditions (collectively described as macromolecular crowding), the crowding environment has been reproduced inside artificial cells. We have previously shown that the combination of macromolecular crowding and microscale geometries imposed by the artificial cells can alter the molecular behaviors induced by macromolecular crowding in bulk solutio

Micrometric membrane confinements and macromolecular crowding of cytoplasm are key factors that regulate molecular diffusion in live cells. Previous studies have shown that macromolecular crowding delays molecular diffusion. However, the effect of cell-size confinement on diffusion in the crowding environment is yet to be elucidated. Using fluorescence correlation spectroscopy (FCS), we analyzed protein diffusion in microdroplets containing polymer solution covered with lipid membranes that mimi

Molecular behaviors in small liquid droplets (picoliter scale), such as phase transitions and chemical reactions, are essential for the industrial application of small droplets and their use as artificial cells. However, the droplets often differ from those in bulk solutions (milliliter scale). Since the droplet size is much larger than the molecular size, the so-called size effect that draws these differences has attracted attention as a target to be solved. Although the small volume and the me

Gelatin microgels prepared inside lipid droplets have a much higher elasticity than that of bulk gels because of their differences in nanostructure. This nanostructural difference in gelatin microgels is expected to provide the microgels with unique viscoelastic properties that differ from the bulk gels. To clarify this hypothesis, here we evaluated the frequency-dependent viscoelasticity of gelatin gels by developing a cyclic micropipette aspiration. The frequency-dependent relationship between