A microfluidic cell lysis chip equipped with a micromixer and SPE unit was developed and used for quantitative analysis of intracellular proteins. This miniaturized sample preparation system can be employed for any purpose where cell disruption is needed to obtain intracellular constituents for the subsequent analysis. This system comprises a ...

Cell-penetrating peptides (CPPs) including TAT peptide (TATp) have been successfully used for intracellular delivery of a broad variety of cargoes including various nanoparticulate pharmaceutical carriers (liposomes, micelles, nanoparticles). Here, we will consider the main results in this area, with a special emphasis on TATp-mediated delivery of liposomes and DNA. We ...

Electrical synapses continuously transfer signals bi-directionally from one cell to another, directly or indirectly via intermediate cells. Electrical synapses are common in many brain structures such as the inferior olive, the subcoeruleus nucleus and the neocortex, between neurons and between glial cells. In the cortex, interneurons have been shown to ...

Dental magnetic attachments, usually applied locally to oral cavities, produce stray fields (flux leakage) spreading in adjacent tissues. It has been found that human periodontal ligament (PDL) cells change their geometry and the structure of their cytoskeleton F-actins when the cell cultures are exposed to B-field strengths of B = ...

In view of micro fuel cells, the silicon processes are employed for microfabrication of the micro direct methanol fuel cell (µDMFC). Using the MEMS technology we have successfully made single µDMFC as small as 10mm×8mm×3mm. The main reason for the use of MEMS processes is the prospective potential for miniaturization ...

Studying cell behaviour under irradiation with radiofrequency electromagnetic fields (RF-EMF) is often impeded by the difficulty to monitor cell characteristics during irradiation. Here we report the design and the application of a complete device for continuous microscopic observation of cells exposed to modulated EMF similar to mobile phones signals. The ...

Half-cell potential testing has been recommended as a non-destructive method for assessing the corrosion potential of reinforcing steel in concrete bridge decks. The technique is particularly useful because it can be utilized to evaluate the probability of corrosion before damage is evident at the surface of a bridge deck. The ...

Shewanella oneidensis MR-1 grew for over 50 days in microbial fuel cells, incompletely oxidizing lactate to acetate with high recovery of the electrons derived from this reaction as electricity. Electricity was produced with lactate or hydrogen and current was comparable to that of electricigens which completely oxidize organic substrates. However, ...

We present an integrated circuit/microfluidic chip that traps and moves individual living biological cells and chemical droplets along programmable paths using dielectrophoresis (DEP). Our chip combines the biocompatibility of microfluidics with the programmability and complexity of integrated circuits (ICs). The chip is capable of simultaneously and independently controlling the location ...

Galvanotaxis, that is, migration induced by DC electric fields, is thought to play a significant role in development and wound healing, however, the mechanisms by which extrinsic electric fields orchestrate intrinsic motility responses are unknown. Using mammalian cell lines (3T3, HeLa, and CHO cells), we tested one prevailing hypothesis, namely, ...

NAADP (nicotinic acid adenine dinucleotide phosphate) is a recently discovered second messenger, and as such, we have much yet to learn about its functions in health and disease. A bottleneck in this basic research is due to NAADP, like all second messengers, being charged to prevent it from leaking out ...

Polypyrrole (PPy) is a conducting polymer that may be electrochemically generated with the incorporation of any anionic species, including net-negatively charged biological molecules such as proteins and polysaccharides. In this article, dermatan and chloride-loaded PPy films were prepared on gold sputter-coated coverslips and various skin derived cells were studied on ...

The paper presents a couple of biofluidic devices, whose functions are inspired from biological cell concentration and deformability monitoring functions. The cell concentration monitoring chip is inspired from RBC control mechanism in kidney, performing cell concentration monitoring functions. The cell deformability chip, inspired from selective RBC destruction mechanism in spleen, ...

PURPOSE: To evaluate the effects of the static magnetic field and typical imaging sequences of a high-field magnetic resonance scanner (3 Tesla) on the induction of double-strand breaks (DSBs) in two different human cell lines. MATERIALS AND METHODS: Human promyelocytic leukemia cells (HL-60) and human acute myeloid leukemia cells (KG-1a) ...

In order to understand the behavior of individual cells, single cell analyses have attracted attention since most cell-based assays provide data with values averaged across a large number of cells. Techniques for the manipulation and analysis of single cells are crucial for understanding the behavior of individual cells. In the ...

A piezoelectric actuated, drop-on-demand inkjet printing system has been used to deliver suspensions of human fibroblast cells from a well-characterized cell line (HT 1080) in order to investigate the behaviour of cells exposed to the mechanical and fluid stresses associated with the printing process. By varying the amplitude and rise ...

Magnetic particles have been used widely in both biotechnological and medical fields, including for immunoassay, enzyme immobilization, drug transport, and immunological diagnosis. Especially particles with bioactive molecules such as antibodies and streptavidin are very useful tools for cell separation. Here we report affinity selection of neutrophils and macrophages from peritoneal ...

In this study, we present a new, simple and rapid impedance method to detect bacterial cells by making use of the impedance properties of bacterial cell suspensions using interdigitated microelectrodes. It was found that bacterial cell suspensions in deionized (DI) water with different cell concentrations could generate different electrical impedance ...

We developed an in situ IR transmission electrochemical cell, which was initially used to study lithium intercalation in a phospho-olivine LixFePO4 cathode. We had previously characterized vibrational spectrum of this material as part of a preliminary study. The transition between LiFePO4 and FePO4 could easily be followed in the in ...

INTRODUCTION: Most cardiac arrhythmias are associated with pathology-triggered ion channel remodeling. However, multicellular effects, for example, exaggerated anisotropy and altered cell-to-cell coupling, can also indirectly affect action potential morphology and electrical stability via changed electrotonus. These changes are particularly relevant in structural heart disease, including hypertrophy and infarction. Recent computational ...

Micropatterning of target cells is highly desired for tissue engineering and cell biology. Although recent progress in surface chemistry has enabled the spatial control of cell adhesion onto substrates, conventional methods usually require specialized devices and time-consuming processes to fabricate the substrate. In this study, we demonstrate a simple and ...

The mechanisms by which cancer cells migrate to metastasise are not fully understood. Breast cancers are accompanied by electrical depolarisation of tumour epithelial cells. The electrical changes can be detected on the skin and are used to differentiate malignant from benign breast tumours. Could the electrical signals play a role ...

This work presents a microfluidic device to capture physically single cells within microstructures inside a channel and to measure the impedance of a single HeLa cell (human cervical epithelioid carcinoma) using impedance spectroscopy. The device includes a glass substrate with electrodes and a PDMS channel with micro pillars. The commercial ...

Since 1984, electric cell-substrate impedance sensing (ECIS) has been used to monitor cell behavior in tissue culture and has proven sensitive to cell morphological changes and cell motility. We have taken ECIS measurements on several cultures of noncancerous and cancerous human ovarian surface epithelial cells. By analyzing the noise in ...

Applications of dc electric field across parallel plate electrodes filled with an aqueous dispersion of carbon nanotubes produce slowly changing, geometrically regular patterns over the anode surface. The pattern is made visible by nonuniform concentration distributions of black-colored carbon nanotubes. Temporal developments of the pattern can be categorized to the ...

Solid oxide fuel cells are devices that have the potential to efficiently produce electricity while creating little pollution. The development of a suitable interconnect is one of the primary technological hurdles that is holding back their commercial viability. An interconnect has two primary functions in a planar solid oxide fuel ...

Electrochemical studies were performed to explore electron transfer (ET) between human white blood cells (WBC) and carbon fiber electrodes (CFE). Currently, an active area of research involves encouraging ET between microbes and various electrodes in a biofuel cell (BFC). ET between microbes and electrodes are thought to occur i) directly ...

We recently pioneered the ability to directly electrospin living cells from which scaffolds to membranes were derived. This protocol, now widely referred to as 'cell electrospinning', is currently undergoing in-depth investigations where the post-treated cell's global gene expression to its sub-cellular components is being investigated for understanding any effects post-treating. ...

A microfluidic electroporator operating under a continuous low dc voltage (7 to approximately 15 V) is reported. The proposed electroporation microchip exploits the ionic conductivity of polyelectrolytic gel electrodes to precisely control the electric field that is applied to cells without bubble generation in the microchannel. In this study, pDADMAC ...

We report here the sonoporation of HL60 (human promyelocytic leukemia) suspension cells in a microfluidic confinement using a single laser-induced cavitation bubble. Cavitation bubbles can induce membrane poration of cells located in their close vicinity. Membrane integrity of suspension cells placed in a microfluidic chamber is probed through either the ...

We report here a non-invasive, reversible method for interrogating single cells in a microfluidic flow-through system. Impedance spectroscopy of cells held at a micron-sized pore under negative pressure is demonstrated and used to determine the presence and viability of the captured cell. The cell capture pore is optimized for electrical ...

Asymmetrical delivery of stimuli to moving cells for perturbing spatially-heterogeneous intracellular signaling is an experimental challenge not adequately met by existing technologies. Here, we report a robust microfluidic platform allowing localized treatment of the front and/or back of moving cells which crawl through narrow channels that they completely occlude. The ...

A novel method of modeling multiple frequency dielectrophoresis (MFDEP) is introduced based on the concept of an effective Clausius-Mossotti factor, CM(eff), for a particle that is exposed to electrical fields of different frequencies, coming either from one or multiple pairs of electrodes. This analysis clearly illustrates how adding frequencies adds ...

The purpose of this study was to investigate the effect of a polymer coating using modified polyvinyl alcohol (PVA-R) on the interaction between liposomes and macrophage cells (J774 cells). The PVA-R-coated liposomes, which were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocianin perchlorate (DiI) as a fluorescence reagent, were prepared with the conventional hydration method ...

Cell survival following exposure to spatially modulated beams, as created by intensity-modulated radiotherapy (IMRT), is investigated. In vitro experiments were performed using malignant melanoma cells (MM576) exposed to a therapeutic megavoltage photon beam. We compared cell survival in modulated fields with cell survival in uniform control fields. Three different spatial ...

Electrogenic cells are able to generate electrical signals which can be measured by various invasive electrophysiological methods such as patch-clamp or sharp microelectrode recordings. Growing cells on the surfaces of e.g. metal microelectrodes or field-effect transistors allows the recording of an extracellular component of these signals. For an understanding of ...

The culture of anchorage dependent mammalian cells on microcarrier offers an attractive avenue for achieving high productivity of therapeutic and diagnostic proteins in bioreactors. Reducing production costs require high cell density that is accompanied by mass transfer limitations of nutrients and oxygen. High agitations required to overcome these limitations can ...

This study presents a new cell manipulation method using a moving dielectrophoretic force to transport or fractionate cells along a microfluidic channel. The proposed moving dielectrophoresis (mDEP) is generated by sequentially energizing a single electrode or an array of electrodes to form an electric field that moves cells continuously along ...

The micro structured deposition of vital cells is an important challenge in tissue engineering, biosensor technology, and in all research dealing with cell-cell and cell-substrate contacts. Hence, an inkjet printing technology has been developed to manufacture Au-based micro electrodes by sputter coating inversely printed polyester-foils. These electrodes feature minimal structure ...

The interaction of nanosecond duration pulsed electric fields (nsPEFs) with biological cells, and the models describing this behavior, depend critically on the electrical properties of the cells being pulsed. Here, we used time domain dielectric spectroscopy to measure the dielectric properties of Jurkat cells, a malignant human T-cell line, before ...

The cytosol of a single adherent cell was collected by the electrical cell lysis method with a Pt-ring capillary probe, and the cellular messenger RNA (mRNA) was analyzed at a single-cell level. The ring electrode probe was positioned 20 microm above the cultured cells that formed a monolayer on an ...

This paper deals with the effective design of smart microrobots for both mechanical cell characterization and cell convoying for in vitro fertilization. The first microrobotic device was developed to evaluate oocyte mechanical behavior in order to sort oocytes. A multi-axial micro-force sensor based on a frictionless magnetic bearing was developed. ...

CPPs (cell-penetrating peptides), including Tatp (transactivator of transcription peptide), have been successfully used for intracellular delivery of a wide variety of cargoes including various nanoparticulate pharmaceutical carriers such as liposomes, micelles and nanoparticles. Here, we will consider the major results obtained in this area with emphasis on Tatp-mediated delivery of ...

Intracellular hyperthermia is a process by which malignant cells can be selectively killed by heat generated by nanomediators located inside the cell. Here we show that maghemite anionic nanoparticles are efficiently captured by human prostatic tumor cells (PC3) and concentrate within intracellular vesicles. When submitted to an alternative magnetic field, ...

Technologies for fabricating functional tissue architectures by patterning cells precisely are highly desirable for tissue engineering. Although several cell patterning methods such as microcontact printing and lithography have been developed, these methods require specialized surfaces to be used as substrates, the fabrication of which is time consuming. In the present ...

This is a brief introduction to the emerging field of irreversible electroporation in medicine. Certain electrical fields when applied across a cell can have as a sole effect the permeabilization of the cell membrane, presumable through the formation of nanoscale defects in the cell membrane. Sometimes this process leads to ...

The periodicity of photonic crystals can be utilized to develop efficient numerical methods for analyzing light waves propagating in these structures. The Dirichlet-to-Neumann (DtN) operator of a unit cell maps the wave field on the boundary of the unit cell to its normal derivative, and it can be used to ...

A precise characterization of cell elastic properties is crucial for understanding the mechanisms by which cells sense mechanical stimuli and how these factors alter cellular functions. Optical and magnetic tweezers are micromanipulation techniques which are widely used for quantifying the stiffness of adherent cells from their response to an external ...

Contactless simultaneous positioning of micrometer-sized particles in suspension (e.g., copolymer beads, living cells, silicon microparts) can be performed using ultrasound. Current devices are capable of collecting particles into planes or lines by exciting a resonance in the fluid by means of a piezoelectric transducer located beneath the fluidic cavity and ...

Self-reproduction is one of main properties that define living cells. In order to explore the self-reproduction process for the study of early cells, and to develop a research line somehow connected to the origin of life, we have built up a constructive 'synthetic cells (minimal cells)' approach. The minimal cells ...