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Results 301 - 350 of 1685
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Huang Ching-Wen - - 2009
We report a microfluidic cell culture chip that was used for long-term electrotaxis study on a microscope. The cellular response under three different electric field strengths was studied in a single channel microfluidic chip. Electric field (EF) inside the microchamber was numerically simulated and compared to the measured value. Lung ...
Sîrbulescu Ruxandra F - - 2009
In contrast to mammals, teleost fish exhibit an enormous potential to regenerate adult spinal cord tissue after injury. However, the mechanisms mediating this ability are largely unknown. Here, we analyzed the major processes underlying structural and functional regeneration after amputation of the caudal portion of the spinal cord in Apteronotus ...
Curtis Theresa M - - 2009
A major limitation to using mammalian cell-based biosensors for field testing of drinking water samples is the difficulty of maintaining cell viability and sterility without an on-site cell culture facility. This paper describes a portable automated bench-top mammalian cell-based toxicity sensor that incorporates enclosed fluidic biochips containing endothelial cells monitored ...
Kaneda Makoto - - 2009
Liposomes are widely utilized in molecular biology and medicine as drug carriers. Here we report a new liposome-cell interaction through connexins. Connexin 43 (Cx43)-containing liposomes were prepared by using cell-free transcription/translation systems with plasmids encoding Cx43 in the presence of liposome. The expressed membrane protein, Cx43, was directly constituted to ...
Shafiee Hadi - - 2009
Dielectrophoresis (DEP) has become a promising technique to separate and identify cells and microparticles suspended in a medium based on their size or electrical properties. Presented herein is a new technique to provide the non-uniform electric field required for DEP that does not require electrodes to contact the sample fluid. ...
Chuang Cheng-Hsin - - 2009
Electrorotation (ER) has become a very powerful diagnostic technique for the measurement of dielectric properties of cells. However, only a few papers have investigated the electric-induced rotation of particles in a stationary alternating (AC) electric field instead of a rotating electric field. In this study, a microchip composed of a ...
Furukawa Shunsuke - - 2009
It is well known that Paramecium species including green paramecia (Paramecium bursaria) migrate towards the anode when exposed to an electric field in a medium. This type of a cellular movement is known as galvanotaxis. Our previous study revealed that an electric stimulus given to P bursaria is converted to ...
Masunaga Shin-Ichiro - - 2009
SCC VII tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all intratumor proliferating (P) cells. They received hexamethylenetetramine (HMTA) either once intraperitoneally or continuously subcutaneously together with chemotherapy using intraperitoneally administered free doxorubicin (DXR) or intravenously injected pegylated liposomal doxorubicin (PLD). One hour after the free DXR loading or ...
Choi Youn-Suk - - 2009
A microfabricated cell-based testing device for electrochemotherapy (ECT) has been developed; it mimics a clinical electroporator with a circular needle array and maintains a similar electric field strength distribution. Until now, the performance between electroporators having two- and six-needle circular array electrodes, which are the general needle-type clinical electroporators for ...
Krebs Melissa D MD Department of Biomedical Engineering, Case Western Reserve University, 204 Wickenden, 10900 Euclid Avenue, Cleveland, Ohio 44106, - - 2009
The creation of ordered cellular structures is important for tissue engineering research. Here, we present a novel strategy for the assembly of cells into linear arrangements by negative magnetophoresis using inert, cytocompatible magnetic nanoparticles. In this approach, magnetic nanoparticles dictate the cellular assembly without relying on cell binding or uptake. ...
Male Keith B - - 2009
A noninvasive technique based on electric cell-substrate impedance sensing (ECIS) was demonstrated for on-line probing inhibitory effects of five destruxins on Spodoptera frugiperda Sf9 insect cells. Such chemically structurally similar cyclic hexadepsipeptides, were isolated and purified from the fungus Metarhizium anisopliae. Based on a response function, the inhibitory effect of ...
Inaba Rina - - 2009
Adherent cells, cell sheets, and spheroids were harvested noninvasively from a culture surface by means of electrochemical desorption of a self-assembled monolayer (SAM) of alkanethiol. The SAM surface was made adhesive by the covalent bonding of Arg-Gly-Asp (RGD)-peptides to the alkanethiol molecules. The application of a negative electrical potential caused ...
Rahman A - - 2009
We report on the electrical impedance spectroscopy (EIS) characterization of OVCA429 ovarian cancer cells. A commercially available eight-well cell culture impedance array (ECIS-8W1E), commonly used in Electrical Cell-substrate Impedance Sensing (ECIS$\x;{TM}$), was used for OVCA429 characterization. Impedances of ECIS-8W1E array were recorded with cell culture medium (without cells) and with ...
Sauer A M - - 2009
Magnetofection, gene delivery under the influence of a magnetic field, is a technique to increase transfection efficiency by enforcing gene vector contact with a target cell. Mechanisms of magnetic lipoplex internalization and intracellular details of magnetofection are still unknown. In this study, cellular dynamics of magnetic lipoplexes were examined in ...
Chen Chao-Bin - - 2009
Through the use of superparamagnetic iron oxide nanoparticles (SPIONs), fast delivery of DNA into adherent and suspended cells could be achieved by the mediation of a strong impulsed magnetic field. Mammalian cells were well transfected with enhanced green fluorescent protein gene. To mediate the cellular uptake, cells and nucleic acid ...
Vahey M D MD Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 36-824, Cambridge, Massachusetts 02139, - - 2009
Separations can be broadly categorized as preparative, where the objective is to extract purified quantities of a sample from a complex mixture, or analytic, where the goal is to determine and quantify the contents of the original mixture. Here we demonstrate the application of a new microfluidic separation method, isodielectric ...
Schrlau Michael G - - 2009
The ability to monitor living cell behavior in real time and with high spatial resolution is vital for advancing our knowledge of cellular machinery and evaluating cellular response to various drugs. Here, we report the development and utilization of carbon-based nanoelectrodes for cell electrophysiology. We employ carbon nanopipettes (CNPs), novel ...
Weber Wilfried - - 2009
Targeted delivery of therapeutic transgenes into specific cells remains a highly relevant challenge for tissue engineering and future gene-based therapies. We have designed streptavidin-pseudotyped lentiviral particles which upon coupling with biotinylated magnetic carbon-coated cobalt nanoparticles could be guided by magnetic fields to site-specifically transduce desired target cells in culture as ...
Valley Justin K - - 2009
Electroporation is a common technique for the introduction of exogenous molecules across the, otherwise, impermeant cell membrane. Conventional techniques are limited by either low throughput or limited selectivity. Here we present a novel technique whereby we use patterned light to create virtual electrodes which can induce the parallel electroporation of ...
Rümenapp Christine - - 2009
This study describes the use of impedance spectroscopy as a non-invasive tool to monitor cell proliferation and morphology and to obtain better measurements of cell kinetics. The goal was to determine test frequencies at which the cell behaviour towards different chemicals and toxins can be monitored with good time resolution. ...
Vijayalaxmi - - 2009
PURPOSE: A meta-analysis was conducted to obtain a 'quantitative' estimate of the extent of genetic damage in mammalian somatic cells exposed to non-ionizing radiation emitted from extremely low frequency electro-magnetic fields (ELF-EMF) and to compare with that in unexposed control cells. METHODS: The methods used for the meta-analysis were recommended ...
Zhan Yihong - - 2009
Droplet-based microfluidics has raised a lot of interest recently due to its wide applications to screening biological/chemical assays with high throughput. Despite the advances on droplet-based assays involving cells, gene delivery methods that are compatible with the droplet platform have been lacking. In this report, we demonstrate a simple microfluidic ...
Kavan Ladislav - - 2009
A recently developed rotating spectroelectrochemical cell for in situ Raman spectroscopic studies of photoreactive compounds without marked decomposition of the sample is presented. Photochemically and thermally sensitive redox systems are difficult to be studied under stationary conditions by in situ spectroelectrochemistry using laser excitation as in Raman spectroscopy. A rotating ...
Lu Shaoying S Department of Bioengineering, University of California San Diego, La Jolla, 92093-0412, USA. - - 2009
There is a growing body of experimental evidence suggesting that the Ca(2+) signaling in ventricular myocytes is characterized by a high gradient near the cell membrane and a more uniform Ca(2+) distribution in the cell interior [1]--[7]. An important reason for this phenomenon might be that in these cells the ...
Samuel Stanley S Department of Radiology, University of Michigan Medical Center, Ann Arbor, MI, USA. - - 2009
The objective of this study was to investigate the influences of total exposure duration and pulse-to-pulse bubble distribution on contrast-mediated cell damage. Murine macrophage cells were grown as monolayers on thin polyester sheets. Contrast agent microbubbles were attached to these cells by incubation. Focused ultrasound exposures (P(r) = 2 MPa) ...
Lee Kun-Mu - - 2009
A poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine) (PProDOT-Et2) counter electrode was incorporated in a plastic dye-sensitized solar cell (DSSC) to substitute for Pt electrode. The surface morphology and I-/I3- redox behaviors based on PProDOT-Et2 and sputtered-Pt electrodes were characterized, and their performances as counter electrodes in the plastic-DSSCs were compared. Cells fabricated with a PProDOT-Et2 ...
Ino Kosuke - - 2009
To investigate the effects of cell-cell interactions on cellular function, the microenvironment surrounding cells should be precisely controlled. Here, we describe a cell patterning technique, which utilizes magnetic force and magnetite nanoparticles. This method was used to develop cell culture arrays for investigation of cell behaviors in angiogenesis. Pin holder ...
Ziv Roee - - 2009
Micro-electroporation is an electroporation technology in which the electrical field that induces cell membrane poration is focused onto a single cell contained in a micro-electromechanical structure. Micro-electroporation has many unique attributes including that it facilitates real time control over the process of electroporation at the single cell level. Flow-through micro-electroporation ...
Choi Youn-Suk - - 2009
A microfabricated cell-based testing device for electrochemotherapy (ECT) has been developed by miniaturizing the widely used clinical electroporator with a two-needle array into two-dimensional planar electrodes while keeping the similarity of the electric field strength distribution. In this device, all the biological processes from cell culture to electroporation and final ...
Kim Jeong Ah - - 2009
A common problem with the in vivo therapeutic applications of cells is that cells can rapidly disappear into the circulatory system after an injection. Magnetic nanoparticles can be used to solve this problem. Bacterial magnetic nanoparticles were used in this study for targeting stem cells at a specific location within ...
Clauwaert Peter - - 2009
Using the anode effluent to compensate the alkalinization in a bio-cathode has recently been proposed as a way to operate a microbial fuel cell (MFC) in a continuous and pH neutral way. In this research, we successfully demonstrated that the operation of a MFC without any pH adjustments is possible ...
Sagmeister Brigitte P - - 2009
For the application of high fundamental frequency (HFF) quartz crystal resonators as ultra sensitive acoustic biosensors, a tailor-made quartz crystal microbalance (QCM) flow cell has been fabricated and tested. The cell permits an equally fast and easy installation and replacement of small and fragile HFF sensors. Usability and simple fabrication ...
Lee Won Gu - - 2009
Microscale engineering plays a significant role in developing tools for biological applications by miniaturizing devices and providing controllable microenvironments for in vitro cell research. Miniaturized devices offer numerous benefits in comparison to their macroscale counterparts, such as lower use of expensive reagents, biomimetic environments, and the ability to manipulate single ...
Tarantola Marco - - 2009
In the growing field of nanotechnology, there is an urgent need to sensitively determine the toxicity of nanoparticles since many technical and medical applications are based on controlled exposure to particles, that is, as contrast agents or for drug delivery. Before the in vivo implementation, in vitro cell experiments are ...
Opp Daniel - - 2009
In vitro assessment of cytotoxicity based on electrochemical impedance spectroscopy (EIS) needs more quantitative methods to analyze the alteration of cell morphology and motility, and hence the potential risk to human health. Here, we applied electric cell-substrate impedance sensing (ECIS) to evaluate dose-dependent responses of human umbilical vein endothelial cells ...
Bortoli Giorgia Moura de - - 2009
Pesticides have been considered potential chemical mutagens and various agrochemical ingredients possess mutagenic properties. Biomonitoring provides a useful tool to estimate the genetic risk from exposure to a complex mixture of chemicals. In general genetic damage associated with pesticides occurs in human populations subject to high exposure levels due to ...
Paoletti Elena - - 2009
Leaf-level microscopical symptom structure and physiological responses were investigated in seedlings experimentally exposed to ozone (O3) in indoor chambers (150 ppb, 8 h d(-1)/7 weeks), and field trees of Manna ash (Fraxinus ornus) exposed to ambient O3 (max 93 ppb/one growing season). Ozone-induced leaf injury, including leaf reddening and stippling, ...
Park Ji Sun - - 2009
In this study, the potential of gold nanoparticles (20 nm) to deliver electrical stimulation to nerve cell cultures in vitro to induce nerve regeneration was evaluated. In order to use these biomaterials to deliver an electrical stimulus, we devised a novel method for the fabrication of a nanostructured 2D substrate ...
Sen Atanu - - 2009
Electrochemical measurement of transmitter or hormone release from individual cells on microchips has applications both in basic science and drug screening. High-resolution measurement of quantal exocytosis requires the working electrode to be small (cell-sized) and located in immediate proximity to the cell. We examined the ability of candidate electrode materials ...
Yan Xiaolong - - 2009
Endogenous direct-current electric fields (dcEFs) occur in vivo in the form of epithelial transcellular potentials or neuronal field potentials. A variety of cells respond to dcEFs by migrating directionally, and this is termed galvanotaxis. The mechanism by which dcEFs direct cell movement, however, is not yet understood, and the effects ...
Jel??nek Frantisek - - 2009
Fr??hlich postulated coherent polar oscillations as a fundamental biophysical property of biological systems. Recently, Pelling et al. (2004, 2005) detected mechanical vibrations of yeast cell membrane with atomic force microscope (AFM) and analyzed by Fourier analysis in the frequency range 0.5-2 kHz with amplitudes of the order of 1 nm. ...
Taira Shu - - 2009
We developed extremely small functionalized magnetic nanoparticles (MNPs) for use as an in vivo delivery system for pharmaceuticals and biomolecules. We functionalized the MNPs (d = 3 nm) by silanization of amino groups on the particles with (3-aminopropyl)triethoxysilane for subsequent cross-linking with pharmaceuticals and biomolecules. The MNPs were successfully introduced ...
Liu Dan - - 2009
Removal of algal blooms in freshwater using magnetic polymer was studied by magnetic field. Results showed that magnetic polymer at optimal loadings (4 mg/Lferroferric oxide modified with 1.6 mg/Lchitosan) could remove over 99% algal cells; meanwhile, the removal efficiency of COD, total nitrogen and phosphorus was found to be 85.0%, ...
Titushkin Igor - - 2009
Cellular mechanics is known to play an important role in the cell homeostasis including proliferation, motility, and differentiation. Significant variation in the mechanical properties between different cell types suggests that control of the cell metabolism is feasible through manipulation of the cell mechanical parameters using external physical stimuli. We investigated ...
Church Christopher - - 2009
Focusing cells into a single stream is usually a necessary step prior to counting and separating them in microfluidic devices such as flow cytometers and cell sorters. This work presents a sheathless electrokinetic focusing of yeast cells in a planar serpentine microchannel using dc-biased ac electric fields. The concurrent pumping ...
Fosslien Egil - - 2009
In vitro, morphogens such as transforming growth factor (TGF)-beta can up-and down-regulate cell growth at low and high concentrations respectively, i.e. they behave like hormetic agents. The hormetic morphogen theory of curvature proposes that in vivo tissue gradients of such morphogens secreted by source cells determine the fate of cells ...
Wada Hiroshi - - 2009
Using a novel pressure membrane (PM) apparatus for the extraction of apoplastic fluid from field-grown grape (Vitis vinifera L.) berries, our hypothesis that significant apoplast solutes accumulate at the beginning of the ripening process (i.e. veraison), and that this accumulation might contribute to progressive berry softening due to a progressive ...
Joye Neil N Microelectronic Systems Laboratroy, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland. - - 2009
A cell-electrode interface noise model is developed which is dedicated to enable the co-simulation of the cell-electrode electrical characteristics, along with the electronics of novel CMOS-based MEA. The electrode noise is investigated for Pt and Pt black electrodes. It is shown that the electrode noise can be the dominant noise ...
Braeken Dries D Interuniversity MicroElectronics Center (IMEC), Kapeldreef 75, 3001 Leuven, Belgium. - - 2009
In this paper, we describe the localized and selective electrical stimulation of single cells using a three-dimensional electrode array. The chip consisted of 84 nail-like electrodes with a stimulation surface of 0.8 microm(2) and interelectrode distances as small as 3 microm. N2A cells were used to compare bipolar stimulation between ...
Karshafian Raffi - - 2009
This work investigates the effect of ultrasound exposure parameters on the sonoporation of KHT-C cells in suspension by perflutren microbubbles. Variations in insonating acoustic pressure (0.05 to 3.5 MPa), pulse frequency (0.5 to 5.0 MHz), pulse repetition frequency (10 to 3000 Hz), pulse duration (4 to 32 micros) and insonation ...
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