(Press-News.org) Washington, D.C. (October 5, 2010) -- A prototype device developed in Hong Kong will allow laboratory researchers to non-invasively test drugs for their ability to kill tumors by subjecting cancerous cells with different concentration gradients. The new device is built upon microfluidics -- a set of technologies that allows the control and manipulation of fluids at the sub-millimeter scale -- and is described in the American Institute of Physics' journal Biomicrofluidics.
Microfluidic valves within the device, said Hongkai Wu of Hong Kong University of Science and Technology, accurately meter different solutions and mix them to form a stepwise succession of gradients. Then assays measuring cell apoptosis are applied. The device integrates a previously validated analysis method that quantifies the apoptotic process at the level of single cells in real-time.
For this test, researchers measured the activity of the drug etoposide in HeLa cells. Etoposide is a commercially available anticancer compound commonly used in chemotherapy. HeLa cells, derived from human cervical cancer cells, are a line of cells frequently used in research.
The device allows researchers to study the cytotoxicity of multiple concentrations of a drug in parallel on one chip, saving both time and labor and reducing errors caused by variations in conditions often found in larger-scale testing. Also, microfluidic chambers within the device allow long-term tracking of individual cells through fluorescent microscopic imaging that offers high optical sensitivity.
With some other in vitro tests, like DNA analysis, cells need to be killed in order to be studied. In this analysis method, a change in fluorescence occurs when caspase-3, an indicator of cell apoptosis, is activated. In Wu's test, increasing concentrations of etoposide demonstrated correspondingly higher activation of caspase-3. In a control-group chip without etoposide, caspase-3 was not activated.
Wu also said that, "Unlike conventional methods, the microfluidic device permits quantitative data to be obtained from individual cells; the device requires fewer numbers of cells and allows testing of amounts of reagents reduced by about 4 orders of magnitude. In a conventional 96-well plate study, each well is around 1 centimeter, while in our microchip device, each cell chamber has a dimension of hundreds of microns. Reducing the sample size has significant merit because in most cases, the biomolecules in use are extremely expensive, even in quantities in milligrams or less."
While this report concerns a test of five ladder channels on a single chip, higher throughputs should be possible, Wu stated. "This prototype system should be useful in the areas of biology and bioengineering, especially for discovering apoptosis-inducing agents," Wu concluded.
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ABOUT BIOMICROFLUIDICS
Biomicrofluidics is an online open-access journal published by the American Institute of Physics to rapidly disseminate research in elucidating fundamental physicochemical mechanisms associated with microfluidic and nanofluidic phenomena as well as novel microfluidic and nanofluidic techniques for diagnostic, medical, biological, pharmaceutical, environmental, and chemical applications. See: http://bmf.aip.org/
ABOUT AIP
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.
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Washington, D.C. (October 5, 2010) -- The explosion of portable communication devices that we enjoy today -- such as cell and smart phones, Bluetooth hands-free units, and wireless Internet networks -- has resulted in part from the development of a wide variety of integrated circuits that create, process and receive the microwave frequencies on which the communication is based.
Continuing demand for higher performance over a wider range of frequencies has shrunk the physical size of circuits and fueled the development of new materials in thin-film forms, tested in detail ...
Washington, D.C. (October 5, 2010) -- Protein molecules inside cells are constantly reorganizing themselves, driven by very tiny forces exerted by all the other molecules in their crowded environment. Most experimental techniques and theoretical/computational models are necessarily built around much greater driving forces. A new theoretical model reported in the Journal of Chemical Physics investigates the unfolding of fibronectin under gentler conditions.
"Typical models study very fast processes and consume a lot of CPU time," says author Alessandro Pelizzola of the ...
Washington, D.C. (October 5, 2010) -- Carbon nanotubes -- long, hollow cylinders of carbon billionths of a meter in diameter -- have many potential uses in nanotechnology, optics, electronics, and many other fields. The exact properties of nanotubes depend on their structure, and scientists as yet have little control over that structure, which is determined during the initial formation -- or growth -- of the nanotubes. In fact, says chemical engineer and materials scientist Eray Aydil of the University of Minnesota, "we do not know precisely how the nanotubes grow."
In ...
For Immediate Release - (October 5, 2010) –Toronto's Centre for Addiction and Mental Health (CAMH) has been selected as one of seven adult field trial sites in North America and the only site in Canada to test proposed diagnostic criteria for the American Psychiatric Association's (APA) fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Used by health professionals around the world, DSM is the manual that provides descriptions, symptoms and other criteria for diagnosing mental disorders. CAMH is participating in field trials to help assess ...
A research team from the University of British Columbia and the Child & Family Research Institute (CFRI) at BC Children's Hospital has identified the role of a type of T cell in type 1 diabetes that may lead to new treatment options for young patients.
Also known as juvenile diabetes, type 1 diabetes is an autoimmune disease primarily affecting children and young adults. In patients with type 1 diabetes, the body attacks itself by destroying insulin-producing cells in the pancreas that regulate glucose, or blood sugar.
Led by Rusung Tan, a Pathology professor in the ...
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The article will be posted at this URL address the evening of 7 October 2010.
The American Association for the Advancement of Science (AAAS) is the world’s largest general scientific society, and publisher of the journal, Science (www.sciencemag.org) as well as Science Translational Medicine (www.sciencetranslationalmedicine.org) and Science Signaling (www.sciencesignaling.org). AAAS was founded in 1848, and includes some 262 affiliated ...
Spanish and Scottish researchers have added wool fibres to the clay material used to make bricks and combined these with an alginate, a natural polymer extracted from seaweed. The result is bricks that are stronger and more environmentally-friendly, according to the study published recently in the journal Construction and Building Materials.
"The objective was to produce bricks reinforced with wool and to obtain a composite that was more sustainable, non-toxic, using abundant local materials, and that would mechanically improve the bricks' strength", Carmen Galán and ...
Pioneering new research by archaeologists at the University of York suggests that Neanderthals belied their primitive reputation and had a deep seated sense of compassion.
A team from the University's Department of Archaeology took on the 'unique challenge' of charting the development of compassion in early humans.
The researchers examined archaeological evidence for the way emotions began to emerge in our ancestors six million years ago and then developed from earliest times to more recent humans such as Neanderthals and modern people like ourselves. The research by ...
Allergies occur when the defence mechanisms of the immune system malfunction and misread normal substances entering the body as invading pathogens. Antibodies are part of our biochemical arsenal for combating viruses, bacteria, parasites and other alien substances, but during an allergic reaction the antibody, known as IgE, is directed against usually harmless substances such as grass pollen, nuts, pets or eggs. Asthma and allergies are chronic diseases that reduce quality of life and pose an economic burden on society. New parents have therefore previously been asked if ...
Light drinking during pregnancy does not harm a young child's behavioural or intellectual development, reveals research published online in the Journal of Epidemiology and Community Health.
A previous study of 3 year olds drew similar conclusions, but the authors wanted to rule out possible delayed "sleeper" effects in older children.
They used data from the Millennium Cohort Study - a large study tracking the long term health of children born in the UK - drawing on a representative sample of 11,513 children born between September 2000 and January 2002.
Participants' ...
