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Results 251 - 300 of 1668
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Agarwal Aparna - - 2009
Single-cell electroporation using an electrolyte-filled capillary is an emerging technique for transient pore formation in adherent cells. Because adherent cells do not have a simple and consistent shape and because the electric field emanating from the tip of the capillary is inhomogeneous, the Schwan equation based on spherical cells in ...
Gao Yuanfang - - 2009
Neurons and endocrine cells secrete neurotransmitter and hormones in discrete packets in a process called quantal exocytosis. Electrochemical microelectrodes can detect spikes in current resulting from the oxidation of individual quanta of transmitter only if the electrodes are small and directly adjacent to release sites on the cell. Here we ...
Okochi Mina - - 2009
A three-dimensional (3D) cell culture system has been fabricated using a magnetic force based cell patterning method, demonstrating a facile approach for the analysis of invasive capacity of BALB/3T3/v-src using an magnetic force and magnetite nanoparticles. The 3D cell patterning was performed using an external magnetic force and a pin ...
Dittami Gregory M - - 2010
A microchip was applied to electrically depolarize rat pheochromocytoma (PC12) cells and to simultaneously detect exocytotic catecholamine release amperometrically. Results demonstrate exocytosis elicited by flowing cells through an electric field generated by a potentiostat circuit in a microchannel, as well as exocytosis triggered by application of an extracellular voltage pulse ...
Vieira G G Department of Physics, The Ohio State University, Columbus, Ohio 43210, - - 2009
We present a multiplex method, based on microscopic programmable magnetic traps in zigzag wires patterned on a platform, to simultaneously apply directed forces on multiple fluid-borne cells or biologically inert magnetic microparticles or nanoparticles. The gentle tunable forces do not produce damage and retain cell viability. The technique is demonstrated ...
Chebbi Imène - - 2010
Bisphosphonates have been used for decades in the standard therapy of bone-related diseases, including bone metastasis of various malignancies, and they might as well be toxic on early cancer cells themselves. In order to allow a better delivery of neridronate (a N-containing bisphosphonate with relatively poor activity), liposomes were evaluated ...
Zhao Yi - - 2009
1-D magnetic nanowires provide a powerful tool for investigating biological systems because such nanomaterials possess unique magnetic properties, which allow effective manipulation of cellular and subcellular objects. In this study, we report the rotational maneuver of ferromagnetic nanowires and their applications in cell manipulation. The rotational maneuver is studied under ...
Frewin C L - - 2009
Brain machine interface (BMI) devices offer a platform that can be used to assist people with extreme disabilities, such as amyotrophic lateral sclerosis (ALS) and Parkinson's disease. Silicon (Si) has been the material of choice used for the manufacture of BMI devices due to its mechanical strength, its electrical properties ...
Ito Akira - - 2009
In tissue engineering, coculture systems have been employed for two major purposes: (1) construction of tissue and organ substitutes (e.g., coculture of parenchymal and nonparenchymal cells in liver tissue engineering) and (2) maintenance of cellular functions (e.g., coculture of embryonic stem cells with embryonic fibroblasts as the feeder cells). For ...
Yuan Yu - - 2009
We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial ...
Ekmekci Evren - - 2009
This paper presents the results of a feasibility study for the design of multi-band tunable metamaterials based on the use of micro-split SRR (MSSRR) structures. In this study, we have designed and constructed a conventional split-ring resonator (SRR) unit cell (type A) and two modified SRR unit cells having the ...
Suzuki Toshio - - 2009
We report a correlation between the microstructure of the anode electrode of a solid oxide fuel cell (SOFC) and its electrochemical performance for a tubular design. It was shown that the electrochemical performance of the cell was extensively improved when the size of constituent particles was reduced so as to ...
Ito Hiroshi - - 2010
Variability in human cell phenotypes make it's advancements in optimized cell processing necessary for personalized cell therapy. Here we propose a strategy of palm-top sized device to assist physically manipulating cells for optimizing cell preparations. For the design of such a device, we combined two conventional approaches: multi-well plate formatting ...
Okochi Mina - - 2010
A droplet-based cell lysis and reverse transcription-polymerase chain reaction (PCR) were performed on-chip employing magnetic force-based-droplet-handling system. The actuation with a magnet offers a simple system for droplet manipulation; it does not need mechanical fluidic systems such as pumps and valves for handling solutions. It can be used as a ...
Kim Mihye - - 2009
The goal of the present communication was to develop a strategy for detachment of cells and biomaterial constructs from indium tin oxide (ITO) electrodes.
Sakaki Kelly - - 2009
Studies of single cells via microscopy and microinjection are a key component in research on gene functions, cancer, stem cells, and reproductive technology. As biomedical experiments become more complex, there is an urgent need to use robotic systems to improve cell manipulation and microinjection processes. Automation of these tasks using ...
Akiyama Hirokazu - - 2009
We describe the fabrication of three-dimensional tissue constructs using a magnetic force-based tissue engineering technique, in which cellular organization is controlled by magnetic force. Target cells were labeled with magnetite cationic liposomes (MCLs) so that the MCL-labeled cells could be manipulated by applying a magnetic field. Line patterning of human ...
Clow Andrew - - 2009
Automated lab on chip systems offer increased throughput and reproducibility, but the implementation of microelectrodes presently relies on miniaturization of parallel plate electrodes that are time consuming and costly to fabricate. Electric field modelling of open electrofusion chambers suggested that widely spaced (> or =2 mm) coplanar film electrodes should ...
Cha Jaehwan - - 2010
The application of microbial fuel cell (MFC) for wastewater treatment is a promising strategy for the simultaneous treatment of pollutants and generation of electricity. However, for practical application, there are several limitations to the MFC that involve biological and engineering aspects. In this study, a single-chambered MFC able to submerge ...
Wan Alwin M D - - 2009
We describe a conducting polymer device that can induce electrically controlled density gradients of normal and cancerous cell lines, and hence can be used as a tool for the study of cell-cell interactions.
Lentacker Ine - - 2010
Drug delivery with microbubbles and ultrasound is gaining more and more attention in the drug delivery field due to its noninvasiveness, local applicability, and proven safety in ultrasonic imaging techniques. In this article, we tried to improve the cytotoxicity of doxorubicin (DOX)-containing liposomes by preparing DOX-liposome-containing microbubbles for drug delivery ...
Nawalany Kinga - - 2009
Two photosensitizing systems: (1) tetrakis(4-hydroxyphenyl)porphyrin (p-THPP) encapsulated in sterically stabilized liposomes (SSL) and (2) p-THPP functionalized by covalent attachment of poly(ethylene glycol) (p-THPP-PEG(2000)) were studied in vitro. The dark and photo cytotoxicity of these systems were evaluated on two cell lines: HCT 116, a human colorectal carcinoma cell line, and ...
Lee Sang-Min - - 2009
Modularly clickable polymer-caged nanobins (PCNs) were prepared from liposome templates using a drop-in cholesterol-modified poly(acrylic acid) reagent followed by cross-linking with alkyne-functionalized diamine linker that allows for the conjugation of azide-modified targeting ligands via click ligation. These PCNs possess pH-responsive characteristics that can be used to trigger the release of ...
Curtis Theresa M - - 2009
A number of toxicity sensors for testing field water using a range of eukaryotic cell types have been proposed, but it has been difficult to identify sensors with both appropriate sensitivity to toxicants and the potential for long-term viability. Assessment of bovine pulmonary artery endothelial cell (BPAEC) monolayer electrical impedance ...
Papis Elena - - 2009
Magnetic nanoparticles (NPs) have great potential for applications not only as catalysts or energy storage devices, but also in biomedicine, as contrast enhancement agents for magnetic resonance imaging, or for drug delivery. The same characteristics that make cobalt-based NPs so attractive raise serious questions about their safety. In this context, ...
Park Kidong - - 2009
Particle manipulation based on dielectrophoresis (DEP) can be a versatile and useful tool in lab-on-chip systems for a wide range of cell patterning and tissue engineering applications. Even though there are extensive reports on the use of DEP for cell patterning applications, the development of approaches that make DEP even ...
Bothun Geoffrey D - - 2009
Cationic multifluorescent quantum dot liposomes (QD-Ls) have been prepared with both hydrophobic and hydrophilic CdSe/ZnS quantum dots by reverse phase evaporation. QD incorporation was confirmed by fluorescence and confocal microscopy. Incorporation did not affect QD photoactivity or damage bilayer or liposome structure. Cell uptake was examined in human hepatocellular carcinoma ...
Loichen Juliane - - 2009
A new method to affect cells by cell-surface interaction is introduced. Biocompatible magnetic nanobeads are deposited onto a biocompatible magnetic thin layer. The particles are composed of small magnetite crystals embedded in a matrix which can be functionalized by different molecules, proteins or growth factors. The magnetic interaction between surface ...
Taetz Sebastian - - 2009
Cationic hyaluronic acid (HA)-modified DOTAP/DOPE liposomes were designed for the targeted delivery of anti-telomerase siRNA to CD44 receptor-expressing lung cancer cells. DOTAP/DOPE liposomes modified with 1%-20% (w/w) HA-DOPE conjugate were obtained by the ethanol injection method. Their size was below 170 nm and they exhibited zeta potentials higher than +50 ...
Biani Natalia B - - 2009
Cleaning symbioses represent classic models of mutualism, and some bee mites are thought to perform cleaning services for their hosts in exchange for suitable environments for reproduction and dispersal. These mutual benefits, however, have not been rigorously demonstrated. We tested the sanitary role of bee mites by correlating mite loads ...
Jen Chun-Ping - - 2009
The manipulation of biological cells is essential to many biomedical applications. Insulator-based dielectrophoresis (iDEP) trapping consists of insulating structures which squeeze the electric field in a conductive solution to create a non-uniform electric field. The iDEP trapping microchip with the open-top microstructures was designed and fabricated in this work. For ...
Chen Peter - - 2009
Solid-state dye-sensitized solar cells were fabricated using an organic dye, 2-cyanoacrylic acid-4-(bis-dimethylfluoreneaniline)dithiophene (JK2), which exhibits more than 1 V open-circuit potential (V(oc)). To scrutinize the origin of high voltage in these cells, transient V(oc) decay measurements and density functional theroy calculations of the interacting dye/semiconductor surface were performed. A negative ...
Graham Anthony H D - - 2009
The use of CMOS (Complementary Metal Oxide Semiconductor) integrated circuits to create electrodes for biosensors, implants and drug-discovery has several potential advantages over passive multi-electrode arrays (MEAs). However, unmodified aluminium CMOS electrodes may corrode in a physiological environment. We have investigated a low-cost electrode design based on the modification of ...
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 - - 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 - - 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 ...
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