Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotubes glow, even within biological cells

13.12.2004


Scientists use fluorescence to track ultrafine particles taken up by white blood cells

In some of the first work documenting the uptake of carbon nanotubes by living cells, a team of chemists and life scientists from Rice University, the University of Texas Health Science Center at Houston and the Texas Heart Institute have selectively detected low concentrations of nanotubes in laboratory cell cultures.

The research appears in the Dec. 8 issue of the Journal of the American Chemical Society. It suggests that the white blood cells, which were incubated in dilute solutions of nanotubes, treated the nanotubes as they would other extracellular particles – actively ingesting them and sealing them off inside chambers known as phagosomes. "Our goal in doing the experiment was both to learn how the biological function of the cells was affected by the nanotubes and to see if the fluorescent properties of the nanotubes would change inside a living cell," said lead researcher Bruce Weisman, professor of chemistry at Rice. "On the first point, we found no adverse effects on the cells, and on the second, we found that the nanotubes retained their unique optical properties, which allowed us to use a specialized microscope tuned to the near-infrared to pinpoint their locations within the cells."



The research builds upon Weisman’s groundbreaking 2002 discovery that each of the dozens of varieties of semiconducting, single-walled carbon nanotubes (SWNTs) emits its own unique fluorescent signature. The new findings suggest that SWNTs might be valuable biological imaging agents, in part because SWNTs fluoresce in the near-infrared portion of the spectrum, at wavelengths not normally emitted by biological tissues. This may allow light from even a handful of nanotubes to be selectively detected from within the body.

Carbon nanotubes are cylinders of carbon atoms that measure about one nanometer, or one-billionth of a meter, in diameter. They are larger than a molecule of water, but are about 10,000 times smaller than a white blood cell. The latest tests bode well on two counts. Not only did the nanotubes retain their optical signatures after entering the white blood cells, but the introduction of nanotubes caused no measurable change in cell properties like shape, rate of growth or the ability to adhere to surfaces.

In conducting the tests, Weisman was joined by colleagues Paul Cherukuri and Silvio Litovsky, both of the University of Texas Health Science Center at Houston and the Texas Heart Institute, and Sergei Bachilo of Rice. The researchers cultured mouse macrophage cells in solutions containing between zero and 7 parts-per-million carbon nanotubes for periods of up to 96 hours. They found that the amount of carbon nanotubes taken up by the cells increased smoothly as the concentration or the time of exposure increased. In addition, some cultures were run at cooler temperatures and showed a slower rate of uptake, a finding that suggested that the nanotubes were being ingested through normal phagocytosis.

The samples were studied using a spectrofluorometer and a fluorescence microscope that was modified for near-IR imaging through the addition of a digital camera containing indium gallium arsenide detector elements.

Although long term studies on toxicity and biodistributions must be completed before nanotubes can be used in medical tests, the new findings indicate nanotubes could soon be useful as imaging markers in laboratory in vitro studies, particularly in cases where the bleaching, toxicity and degradation of more traditional markers are problematic.

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>