Phase-separated cationic giant unilamellar vesicles as templates for the polymerization of tetraethyl orthosilicate (TEOS).

Unlike homogeneous liposomes, phase-separated liposomes have the potential to be attractive soft materials because they exhibit different properties for each phase. In this study, phase separation was observed when liposomes were prepared using 1,2-dioleoyloxy-3-trimethylammonium propane chloride (DOTAP), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and cholesterol. The pH of the DOTAP-rich phase was evaluated using a coumarin derivative, and measurements showed that DOTAP molecules accumulated hydroxyl ions (OH) in the DOTAP-rich phase.

Effect of mechanical properties on in vitro dynamic digestion of starch contained in hydrogels.

Background: This study evaluates the effect of mechanical properties on the in vitro dynamic gastrointestinal digestion of hydrogels containing starch (HCSs) as a model for studying the nutrient digestibility of solid foods. It provides a useful theoretical basis for the processing of specific foods.

Result: Four types of HCSs with two levels of fracture stress (17.

Facilitated encapsulation of a nonionic contrast agent for X-ray computed tomography into lipid vesicles by the multiple emulsification-solvent evaporation method.

We studied the encapsulation of iohexol (Ihex), a nonionic contrast agent used for X-ray computational tomography, into lipid vesicles using the multiple emulsification-solvent evaporation method to formulate a nanosized contrast agent. This lipid vesicle preparation method consists of three steps: (1) primary emulsification for producing water-in-oil (W/O) emulsions containing fine water droplets that will be converted to the internal water phase of the lipid vesicles, (2) secondary emulsification for formulating multiple water-in-oil-in-water (W/O/W) emulsions encapsulating the fine water droplets containing Ihex, and (3) solvent evaporation to remove the oil phase solvent (n-hexane) and to form lipid bilayers surrounding the fine inner droplets, resulting in the formation of lipid vesicles encapsulating Ihex. As the diameter and Ihex concentration of the primary W/O emulsion droplets decreased, a higher Ihex encapsulation yield was obtained for the final lipid vesicles.

Improvements in Visual Aspects and Chemical, Techno-Functional and Rheological Characteristics of Cricket Powder () by Solvent Treatment for Food Utilization.

This study aimed to improve the visual aspects and chemical, techno-functional and rheological characteristics of cricket powder through the use of different solvents, with the objective of using it as a protein source in food production. Four treatments (pH 5 aqueous solution, ethanol 20%, ethanol 99.5%, and hexane) were applied to the powder, and analyses were conducted to assess changes in the previously mentioned parameters.

Analysis of Calcium Sulfate Scaling Phenomena on Reverse Osmosis Membranes by Scaling-Based Flux Model.

In this study, the behavior of permeate flux decline due to scale precipitation of calcium sulfate on reverse osmosis membranes was investigated. The proposed scaling-based flux model is able to explain that permeate fluxes attributed to three mechanisms of scale precipitation-cake formation, surface blockage, and mixed crystallization-converge to the same newly defined scaling-based critical flux. In addition, a scaling index is defined, which determines whether scale precipitates on the membrane.

Effect of dehydrocholic acid conjugated with a hydrocarbon on a lipid bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine.

The effects of bile acids, dehydrocholic acid (DHA) and DHA conjugated with a hydrocarbon (6-aminohexanoate; 6A-DHA) were evaluated using a lipid bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). DOPC formed a homogenous thin membrane in presence or absence of the DHA, while 20 mol% 6A-DHA induced phase separation on the DOPC thin membrane. It was observed formation of a stomatocyte-like liposomes when these membranes were suspended in a basic solvent.

Freeze-dryable lipid vesicles with size tunability and high encapsulation efficiency prepared by the multiple emulsification-solvent evaporation method.

We investigated the extent of potential applicability of our recently developed method for preparing lipid vesicles [T. Kuroiwa et al., J.

Vicenistatin induces early endosome-derived vacuole formation in mammalian cells.

Homotypic fusion of early endosomes is important for efficient protein trafficking and sorting. The key controller of this process is Rab5 which regulates several effectors and PtdInsPs levels, but whose mechanisms are largely unknown. Here, we report that vicenistatin, a natural product, enhanced homotypic fusion of early endosomes and induced the formation of large vacuole-like structures in mammalian cells.

Formulation and stabilization of nano-/microdispersion systems using naturally occurring edible polyelectrolytes by electrostatic deposition and complexation.

This review paper presents an overview of the formulation and functionalization of nano-/microdispersion systems composed of edible materials. We first summarized general aspects on the stability of colloidal systems and the roles of natural polyelectrolytes such as proteins and ionic polysaccharides for the formation and stabilization of colloidal systems. Then we introduced our research topics on (1) stabilization of emulsions by the electrostatic deposition using natural polyelectrolytes and (2) formulation of stable nanodispersion systems by complexation of natural polyelectrolytes.

PIV and CFD studies on analyzing intragastric flow phenomena induced by peristalsis using a human gastric flow simulator.

This study quantitatively analyzed the flow phenomena in model gastric contents induced by peristalsis using a human gastric flow simulator (GFS). Major functions of the GFS include gastric peristalsis simulation by controlled deformation of rubber walls and direct observation of inner flow through parallel transparent windows. For liquid gastric contents (water and starch syrup solutions), retropulsive flow against the direction of peristalsis was observed using both particle image velocimetry (PIV) and computational fluid dynamics (CFD).

Microcompartmentalized cell-free protein synthesis in semipermeable microcapsules composed of polyethylenimine-coated alginate.

We describe microcompartmentalized cell-free protein synthesis in semipermeable microcapsules prepared from water-in-oil-in-water droplets by a rupture-induced encapsulation method. An aqueous solution of template DNA coding for green fluorescent protein and enzymes for the cell-free protein synthesis was aliquoted into water-in-oil droplets using a microfluidic device, and the droplets were transformed into semipermeable microcapsules. Substrates for protein synthesis diffused into the microcapsules through their semipermeable polyion complex membranes composed of polyethylenimine-coated alginate.

Industrial lab-on-a-chip: design, applications and scale-up for drug discovery and delivery.

Microfluidics is an emerging and promising interdisciplinary technology which offers powerful platforms for precise production of novel functional materials (e.g., emulsion droplets, microcapsules, and nanoparticles as drug delivery vehicles- and drug molecules) as well as high-throughput analyses (e.

Efficient preparation of giant vesicles as biomimetic compartment systems with high entrapment yields for biomacromolecules.

The 'lipid-coated ice-droplet hydration method' was applied for the preparation of milliliter volumes of a suspension of giant phospholipid vesicles containing in the inner aqueous vesicle pool in high yield either calcein, α-chymotrypsin, fluorescently labeled bovine serum albumin or dextran (FITC-BSA and FITC-dextran; FITC=fluorescein isothiocyanate). The vesicles had an average diameter of ca. 7-11 μm and contained 20-50% of the desired molecules to be entrapped, the entrapment yield being dependent on the chemical structure of the entrapped molecules and on the details of the vesicle-formation procedure.

Characterization of phospholipids in membrane vesicles derived from Pseudomonas aeruginosa.

Many Gram-negative bacteria release membrane vesicles (MVs), but their phospholipid properties are poorly understood. Phosphatidylglycerol was present at high levels in MVs derived from Pseudomonas aeruginosa, but not in the cellular outer membrane. The ratio of stearic acid in MVs was high compared to that in the cellular outer membrane.

Formation of monodisperse calcium alginate microbeads by rupture of water-in-oil-in-water droplets with an ultra-thin oil phase layer.

This paper reports a novel formation method of monodisperse calcium alginate microbeads from water-in-oil-in-water (W/O/W) droplets with an ultra-thin oil phase layer. W/O/W droplets containing sodium alginate in an internal aqueous phase were formed as a template of calcium alginate microbeads using a microfluidic device. The ultra-thin oil phase layer of the W/O/W droplets was ruptured by an osmotic pressure difference between the internal and external aqueous phase.

Variation of physiochemical properties and cell association activity of membrane vesicles with growth phase in Pseudomonas aeruginosa.

Pseudomonas aeruginosa and other Gram-negative bacteria release membrane vesicles (MVs) from their surfaces, and MVs have an ability to interact with bacterial cells. Although it has been known that many bacteria have mechanisms that control their phenotypes with the transition from exponential phase to stationary phase, changes of properties in released MVs have been poorly understood. Here, we demonstrate that MVs released by P.

Characterization of a soybean oil-based biosurfactant and evaluation of its ability to form microbubbles.

This paper characterizes the physico-chemical properties of the soybean oil-based polymeric surfactant, Palozengs R-004 (hereafter referred to as R-004). The surface activity of R-004 is comparable to the reported activities of biosurfactants produced by microorganisms and higher than some of the conventional synthetic surfactants. The surface tension of Milli-Q water was reduced to a minimum value of roughly 30mN/m at a concentration of about 0.

Microfluidic preparation of water-in-oil-in-water emulsions with an ultra-thin oil phase layer.

We developed a novel microfluidic device to prepare monodisperse water-in-oil-in-water (W/O/W) emulsions with an ultra-thin (<1 microm) oil phase layer. This microfluidic device was composed of two microchannel junctions, one of which had a step structure, and a uniformly hydrophobic surface for effective oil removal from W/O/W droplets. At the first junction, an internal aqueous phase was transformed into slug-shaped water-in-oil (W/O) droplets by a flow-focusing mechanism.

Pseudomonas quinolone signal affects membrane vesicle production in not only gram-negative but also gram-positive bacteria.

Many Gram-negative bacteria naturally produce membrane vesicles (MVs) to the extracellular milieu. The Pseudomonas quinolone signal (PQS), a quorum-sensing signal of Pseudomonas aeruginosa, is a positive regulator of MV production. In this study, we investigated its effects on MV production in other Gram-negative and -positive bacterial species.

Effect of a local anesthetic lidocaine hydrochloride on the bilayer structure of phospholipids.

The effect of a local anesthetic, lidocaine hydrochloride (LC x HCl), on the bilayer systems of purified egg phosphatidylcholine (EPC), dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) was studied by means of small-angle X-ray scattering (SAXS), Prodan fluorescence and electrophoretic light scattering. In the liquid crystalline phase of EPC and DOPC bilayers, the contraction of lamellar distance by ca. 0.

Effects of surfactant and electrolyte concentrations on bubble formation and stabilization.

As interest in the application of microbubbles grows, it is becoming increasingly important to understand the factors affecting their formation and properties in order to effectively generate microbubbles. This paper investigates the effect of surfactant concentration and electrolyte addition on the size distribution and stability of microbubbles. The anionic surfactant sodium dodecyl sulfate (SDS) was used as the surfactant.

Highly productive droplet formation by anisotropic elongation of a thread flow in a microchannel.

We developed a microfluidic device to form monodisperse droplets with high productivity by anisotropic elongation of a thread flow, defined as a threadlike flow of a dispersed liquid phase in a flow of an immiscible, continuous liquid phase. The thread flow was anisotropically elongated in the depth direction in a straight microchannel with a step, where the microchannel depth changed. Consequently, the elongated thread flow was given capillary instability (Rayleigh-Plateau instability) and was continuously transformed into monodisperse droplets at the downstream area of the step in the microchannel.

Temperature-sensitive nonionic vesicles prepared from Span 80 (sorbitan monooleate).

Different types of nonionic vesicles were prepared from commercial Span 80 (also called sorbitan monooleate), as an inexpensive, biocompatible alternative to conventional phospholipid-based vesicles (liposomes). The vesicles were characterized by different techniques and comparison was made with vesicles formed from POPC (1-palmitoyl-2-oleoyl- sn-glycero-3-phosphocholine) or DOPC (1,2-dioleoyl- sn-glycero-3-phosphocholine). Dynamic light scattering measurements, electron microscopy analyses, and two types of fusion assays indicate that Span 80 vesicles are stable for at least 7 days at 4 or 25 degrees C, while storage at 42 degrees C causes irreversible vesicle fusion.

[Novel method for preparing vesicles from a monodisperse emulsion aimed at controlling the size and improving the entrapment yield].

A vesicle is a compartment composed of lipid bilayer of amphiphilic molecules. The vesicle is applied to carriers of drugs, cosmetics and functional food ingredients in industries. Vesicles are also applied as a model for artificial cell membrane and expected as micro- and nano-reactors.

Novel method for obtaining homogeneous giant vesicles from a monodisperse water-in-oil emulsion prepared with a microfluidic device.

A novel technique called the "lipid-coated ice droplet hydration method" is presented for the preparation of giant vesicles with a controlled size between 4 and 20 microm and entrapment yields for water-soluble molecules of up to about 30%. The method consists of three main steps. In the first step, a monodisperse water-in-oil emulsion with a predetermined average droplet diameter between 4 and 20 microm is prepared by microchannel emulsification, using sorbitan monooleate (Span 80) and stearylamine as emulsifiers and hexane as oil.