Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Voltage tester for beating cardiac cells

18.02.2015

Electrical impulses play an important role in cells of the human body. For example, neurons use these impulses to transmit information along their branches and the body also uses them to control the contraction of muscles.

The impulses are generated when special channel proteins open in the outer envelope of the cells, allowing charged molecules (ions) to enter or exit the cell. These proteins are referred to as ion channels.

Since the 1970s, a method has been available to researchers that enables measurement of the activity of these channels, but until now this method has been used primarily on cells that do not move. Electrical engineers at ETH Zurich and biologists from the University of Bern have now developed the method further, so that they can easily record the activity of moving cells, such as beating cardiac muscle cells in a tissue culture dish.

The existing method involves positioning a glass pipette against the outer membrane of a cell. The opening at the tip of the pipette is so small that it touches only a fraction of the cell surface. Ideally, this tiny patch of cell membrane has exactly one ion channel.

The inside of the pipette is filled with a conductive fluid and an electrode, which makes it possible to measure differences in the charge between the outer part of the cell and cell interior (i.e. an electric potential ) and temporary changes in this potential resulting from activity in the ion channels. The method is referred to as the patch-clamp technique because the pipette is used to clamp a patch of the cell membrane.

Atomic force microscope with micro-injection needle

Lead by Tomaso Zambelli, a lecturer at the Institute of Biomedical Engineering at ETH Zurich, and Hugues Abriel, a professor at the Department of Clinical Research at the University of Bern, the researchers have now combined this technique with an atomic force microscope. A sensor tip is seated on a movable mount - a so called cantilever - to scan the surface of the microscopic object.

Several years ago, the researchers succeeded in producing sensor tips with an internal channel, which allows the computer-controlled injection of molecules into a cell. This technique is now being marketed by the ETH spin-off Cytosurge. However, the scientists continued development of this technique by fitting the micro-injection needle with an electrode to carry out patch-clamp measurements. The researchers have now published the successful results of this venture in the journal Nano Letters.

The patch-clamp technique is not only a central method for basic research in cell biology, it is also used routinely in the development of new drugs. For example, the pharmaceutical industry is legally required as part of the approval process for new drugs to test whether these drugs interact with ion channels. A drug that blocks ion channels may cause severe cardiac dysrhythmia in patients, which should be avoided at all costs.

Longer measurements and automation possible

In the case of the conventional patch-clamp technique, an operator manually positions the pipette against the cell; although automated procedures exists, their applications are limited. Thus, the cells under test must have the same size and shape and must not move (as cardiac cells do).

In the case of the new method, the micro-needle is controlled by a computer using force measurements from the atomic force microscope to hold it at a constant short distance from the cell surface. "This makes the contact between the needle and cell much more stable, which allows us to take measurements over a longer period of time and even test moving cells," explains Zambelli. For the first time, researchers have thus succeeded in measuring electric potential changes in the ion channels of beating cardiac cells. Zambelli says he can also imagine using this as a foundation for development of an automated method for testing any cell, regardless of its shape or size.

###

Literature reference

Ossola D, Amarouch MY, Behr P, Vörös J, Abriel H, Zambelli T: Force-Controlled Patch Clamp of Beating Cardiac Cells. Nano Letters 2015, doi: 10.1021/nl504438z

Media Contact

Tomaso Zambelli
zambelli@biomed.ee.ethz.ch
41-446-324-575

 @ETH_en

http://www.ethz.ch/index_EN 

Tomaso Zambelli | EurekAlert!

More articles from Life Sciences:

nachricht Molecular evolution: How the building blocks of life may form in space
26.04.2018 | American Institute of Physics

nachricht Multifunctional bacterial microswimmer able to deliver cargo and destroy itself
26.04.2018 | Max-Planck-Institut für Intelligente Systeme

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

World's smallest optical implantable biodevice

26.04.2018 | Power and Electrical Engineering

Molecular evolution: How the building blocks of life may form in space

26.04.2018 | Life Sciences

First Li-Fi-product with technology from Fraunhofer HHI launched in Japan

26.04.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>