A low temperature Co-fired ceramic-based dielectrophoretic device for manipulating micro and nanostructure materials.

A dielectophoretic (DEP) device fabricated by a conventional low temperature co-fired ceramic (LTCC) process, for manipulating micro and nanostructure materials, such as spherical polystyrene microspheres, titanium dioxide (TiO2) nanotubes, and silver (Ag) nanowires, is described. To generate a non-uniform electric field, a castellated electrode configuration was applied to the LTCC-based DEP device using a screen printing method. The actual motions of the micro and nanostructure materials under both a positive and a negative DEP force were observed in detail and the findings compared with numerical simulation data for the electric field distribution. The performance of the LTCC-based DEP device for separating and trapping was evaluated and potential applications are discussed.

Influence of different electrolytes and oils on the stability of W1/O/W2 double emulsion during storage and in vitro digestion.

The aim of this study is to formulate a stable water-in-oil-in-water (W1/O/W2) double emulsion using different types of oils and electrolytes. W1/O was formulated with different electrolyte solutions (W1) dispersed in various oils (O) using polyglycerol polyricinoleate as a stabilizer. External aqueous phase was Tween-80 (W2), and W1/O dispersed in W2 was used. The emulsion containing NaCl or MgCl2 exhibited high encapsulation efficiency (EE) and maintained particle size. Regarding the oil type, the emulsion with MCT oil showed a small droplet size and a high viscosity and EE, presenting a stable droplet distribution in optical observation. The stability of emulsion containing NaCl was maintained during the in vitro digestion experiments. MCT oil, NaCl and MgCl2 have the potential to produce stable double emulsions for storage stability and in vitro digestion studies. The findings would be useful for preparing stable double emulsions used in the food and cosmetic industries.

Application of Liposome Encapsulating Lactobacillus curvatus Extract in Cosmetic Emulsion Lotion.

Probiotic extracts have various positive attributes, such as antioxidant, tyrosinase inhibitory, and antimicrobial activity. Lactobacillus curvatus produces bacteriocin, which activates the lipid membrane structure and has potential as a natural preservative for cosmetic emulsions. In this study, L. curvatus extract was encapsulated in liposomes and formulated as an oil-in-water (O/W) emulsion. Radical scavenging activity, tyrosinase inhibition, and challenge tests were conducted to confirm the liposome activity and the activity of the applied lotion emulsion. The liposome-encapsulated extract had a relatively high absolute ζ-potential (52.53 > 35.43), indicating its stability, and 96% permeability, which indicates its potential as an active agent in lotion emulsions. Characterization of emulsions containing the liposomes also indicated a stable state. The liposome-encapsulated extract exhibited a higher radical scavenging activity than samples without the extract and non-encapsulated samples, and the functionality was preserved in the lotion emulsion. The tyrosinase inhibition activity of the lotion emulsion with the liposome-encapsulated extract was similar to that of the non-treated extract. Candida albicans and Aspergillus niger were also inhibited in the challenge test with the lotion emulsions during storage. Collectively, these findings indicate that the liposome-encapsulated extract and the lotion containing the encapsulated extract have potential applicability as natural preservatives.

Effects of Bromelain and Double Emulsion on the Physicochemical Properties of Pork Loin.

Our aim was to investigate the effects of bromelain embedded in double emulsion (DE) on physicochemical properties of pork loin. We evaluated DE characteristics such as size, zeta potential, and microscopy after fabrication. We marinated meat with distilled water (DW), 1% (w/v) bromelain solution, blank DE, and 1% (w/v) bromelain loaded in double emulsion (DE E) for 0, 24, 48, and 72 h at 4°C, and prepared raw meat for control. The marinated samples were assessed for color, water holding capacity, cooking loss, moisture content, pH, protein solubility, Warner-Bratzler shear force (WBSF) and gel electrophoresis. The droplet size of 1% (w/v) bromelain embedded in DE was increased compared with blank DE (p<0.05) and values of zeta potential decreased. The increase in lightness and color difference range of the DE-treated group was lower than that of the DW-treated group (p<0.05). Moreover, treatment by immersion in 1% (w/v) DE E resulted in the highest water holding capacity values (p<0.05) and lower cooking loss values than water base treatment (p<0.05). Results for myofibrillar protein solubility and WBSF showed a similar trend. 1% (w/v) DE E showed degradation of myosin heavy chain after 48 h in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thus, bromelain-loaded DE is useful for controlling and handling enzyme activity in food industry.

Synthesis of One-Dimensional Pillar Arrays by Electrohydrodynamic Jet Printing for Glucose Sensor.

One-dimensional (1-D) Ag arrays were formed by electrohydrodynamic jet-printing (EHD) of polyvinylpyrrolidone (PVP, 1,300 k, Aldrich) solution ink. The 1-D Ag arrays were formed on slide glass by controlling the viscosity and printing conditions such as the tip to the substrate distance, the applied voltage, the flow rate of ink and the velocity. The printed pillars were dried at 80 °C to get rid of the solvent and sintered at 400 °C for 30 min. We found that the arrays of Ag pillars can be fabricated by using the EHD printing method. We could control the diameter of the pillars in the range of 100­200 µm and the length rage between 300 and 700 µm. In order to produce a better performance of glucose sensor, we infiltrated a glucose oxidase as a glucose detector into the Ag pillars previously coated with the mixed solution of multi-walled carbon nanotube (MWCNT, Iljin), Nafion and Pt nanoparticles. In addition, the Ag array electrode with glucose oxidase was used as a working electrode for glucose detection via the three-electrode electrochemical method.

Manipulation of TiO2 Nanotubes in a Transparent Dielectrophoretic Device.

A DEP device with a transparent oxide thin film electrode was fabricated by a photolithography process and sputtering deposition with indium tin oxide (ITO). In order to form a fine ITO electrode pattern, we manipulated the negative slope using a photoresist by controlling the intensity of the ultra-violet radiation and the exposure time. In this study, the motions of a 1 microm polystyrene sphere and TiO2 nanotube were observed as a function of the applied voltage and the frequency. The findings confirm that TiO2 nanotubes can be manipulated by a p-DEP force and that they can be effectively aligned under conditions of 10 V(p-p) at 750 Hz.