Tag Archives: adenosine triphosphate

Animal love and nanotechnology

The researchers at the Fraunhofer Institute for Modular State Technologies (EMFT) have announced a nanosensor technique they’re developing to minimize the use of animals in scientific experiments. From the Jan. 10, 2012 news item on the American Association for the Advancement of Science’s (AAAS) EurekAlert,

Countless mice, rats and rabbits die every year in the name of science – and the situation is getting worse. While German laboratories used some 2.41 million animals for scientific research in 2005, by 2009 this number had grown to 2.79 million. One third were destined for fundamental biology research, and the majority were used for researching diseases and developing medical compounds and devices. People demand medicines that are safe and therapies that are tolerable, but hardly anyone is happy to accept the need for animal testing. [emphasis mine]

Yes, having read studies where they used animals for pain research (I was doing some literature searches and reading for a psychiatrist whose specialty is pain reduction [and, if possible, elimination]), I heartily concur with that last comment. Thank you to all the scientists who are working to eliminate that practice.

Since I’m not sure how long a news item remains posted on EurekAlert, I tracked down the Fraunhofer’s Research News(letter) dated 01.2012 (EMFT) for a description of what they are doing and how they are using nanosensors,

“We’re basically using a test tube to study the effects of chemicals and their potential risks. What we do is take living cells, which were isolated from human and animal tissue and grown in cell cultures, and expose them to the substance under investigation,” explains Dr. Jennifer Schmidt of the EMFT. If a given concentration of the substance is poisonous to the cell, it will die. This change in “well-being” can be rendered visible by the sensor nanoparticles developed by Dr. Schmidt and her team. (p. 5)

Specifically, here’s what they’re tracking and how they’re doing it,

Cells – the tiniest living things – that are healthy store energy in the form of adenosine triphosphate (ATP). High levels of ATP are indicative of high levels of metabolic activity in cells. If a cell is severely damaged, it becomes less active, storing less energy and consequently producing less ATP. “Our nanosensors allow us to detect adenosine triphosphate and determine the state of health of cells. This makes it possible to assess the cell-damaging effects of medical compounds or chemicals,” says Schmidt.

In order for the nanoparticles to register the ATP, researchers give them two fl uorescent dyes: a green indicator dye that is sensitive to ATP, and a red reference dye that does not change color. Next, the scientists introduce the particles to living cells and observe them under a fluorescence microscope. The degree to which the particles light up depends on the quantity of ATP present. The more yellow is visible in the overlay image, [emphasis mine] the more active are the cells. If their health were impaired, the overlay image would appear much redder. “We could in future use cancer cells to test the effectiveness of newly developed chemotherapy agents. If the nanosensors detect a low concentration of ATP in the cells, we’ll know that the new treatment is either inhibiting tumor cell growth or even killing them,” says Schmidt. “The most promising agents could then be studied further.” (p. 5)

This is the “overlay image” mentioned,

The yellow nanosensor signal in the overlay image (right) shows that the cells are active. If they were unhealthy, they would appear much redder. Center: the indicator dye signal. Left: the reference dye signal. Credit: Fraunhofer EMFT

I trust we’ll be hearing more about this research.