Using novel voltage-sensitive nanoparticles, researchers from the University of Michigan have found electric fields inside cells as strong as those produced in lightning bolts.

Previously, it has only been possible to measure electric fields across cell membranes, not within the main bulk of cells. But now it’s possible to measure them. Traditional techniques for studying disease at the level of tissues average out differences between cells. Many developments in cancer research over the past few years have been ‘more reactive’, working toward developing diagnostics for catching the disease in its earlier stages and for better predicting to which drugs patients will respond. Voltage-sensitive dyes are not new. For decades, neuroscientists have used them to measure voltages across cell membranes in studies of how nerve cells generate and respond to electrical charges.

The Experiment:

The researchers encapsulated voltage-sensitive dyes in polymer spheres just 30 nanometers in diameter. When illuminated with blue light, the voltage-sensitive dyes emit a mixture of red and green light; the exact frequency of light emitted is influenced by the strength of local electric fields, allowing the researchers to measure those fields. Testing these nanoparticles in the internal fluid of brain-cancer cells, Kopelman found electric fields as strong as 15 million volts per meter, perhaps five times stronger than the field found in a lightning bolt.

Experts Support:

Piotr Grodzinski, director of the National Cancer Institute Alliance for Nanotechnology in Cancer certifies

They have developed a tool that allows you to look at cellular changes on a very local level. This development represents an attempt to start using nanoscale tools to understand how disease develops.

Jerry S.H. Lee, a nanotechnology project manager also at the National Cancer Institute, says that Kopelman’s research bolsters the set of nanoscale tools that scientists are developing to probe cells’ physical properties, such as special microscopic probes for measuring cell stiffness.

From Kopelman’s Desk:

It’s not possible to control the placement of these dyes in cells. They are hydrophobic and aggregate in cell membranes, so it has not been possible to use them to study the cytosol, the bulk of the interior of the cell. These dyes might be reacting with enzymes and other molecules in cells. His encapsulated dyes aren’t hydrophobic and can operate anywhere in the cell, not just in membranes. Because it’s possible to place his encapsulated dyes in a cell with a greater degree of control, Kopelman likens them to voltmeters.

Hope for Future:

Researchers hope to learn about disease states such as cancer by studying these electric fields.

Via: Technology Review