Featured Research

from universities, journals, and other organizations

Cells Selectively Absorb Short Nanotubes

Date:
April 1, 2007
Source:
National Institute of Standards and Technology (NIST)
Summary:
DNA-wrapped single-walled carbon nanotubes (SWCNTs) shorter than about 200 nanometers readily enter into human lung cells and so may pose an increased risk to health, according to scientists at NIST.

Nanotube length threshold: NIST experiments using human lung cells demonstrate that DNA-wrapped single-walled carbon nanotubes longer than about 200 nanometers are excluded from cells, while shorter lengths are able to penetrate the cell interior (dark lines in the fluorescence image above).
Credit: NIST

DNA-wrapped single-walled carbon nanotubes (SWCNTs) shorter than about 200 nanometers readily enter into human lung cells and so may pose an increased risk to health, according to scientists at the National Institute of Standards and Technology (NIST). The results of their laboratory studies appear in an upcoming issue of Advanced Materials.*

Eyed for uses ranging from electronic displays to fuel cells to water filtration, SWCNTs are tiny cylinders--essentially single-sheet rolls of carbon atoms. They are many times stronger than steel and possess superlative thermal, optical and electronic properties, but safety and biocompatibility remain an open question.

"Published data citing in vitro (outside the body) toxicity are particularly inconsistent and widely disputed," writes biomaterials scientist Matthew Becker and his NIST colleagues. Public concerns surrounding the environmental, health and safety impacts of SWCNTs could derail efforts to fast track the development of nanotubes for advanced technology applications. A significant hurdle in outlining the parameters contributing to nanotube toxicity is to prepare well-defined and characterized nanotube samples, as they typically contain a distribution of lengths, diameters, twists and impurities.

The team chose to isolate the effects of nanotube length. They first adsorbed short DNA molecules onto the nanotubes because this renders them soluble in water and allows them to be sorted and separated by length. The researchers then exposed human lung fibroblasts to solutions containing unsorted nanotubes. Regardless of the concentration levels, the cells did not absorb between about one-fourth and one-third of the SWCNTs in the solutions. Further examination of the results revealed that only short nanotubes made it into the cellular interior.

In the next phase of the research, the team exposed the cells to sorted nanotubes of controlled length. They found that tubes longer than about 200 nanometers were excluded from the cells and remained in solution. Cells exposed to the longer nanotube solutions did not undergo a decrease in metabolic activity, but cells exposed to nanotubes below that threshold absorbed them and, depending on the concentration level, died or showed other signs of toxicity. "Our results demonstrate that cellular uptake in these lung cells depends significantly on the length of the nanotubes," Becker explains. "This is the first of many steps in the critical goal of reducing health risk by de novo engineering of the nanotubes themselves."

*M.L. Becker, J.A. Fagan, N.D. Gallant, B.J. Bauer, V. Bajpai, E.K. Hobbie, S.H. Lacerda, K. B. Migler and J.P. Jakupciak. Length-dependent uptake of DNA-wrapped single-walled carbon nanotubes. Advanced Materials, published online : 20 March 2007.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology (NIST). "Cells Selectively Absorb Short Nanotubes." ScienceDaily. ScienceDaily, 1 April 2007. <www.sciencedaily.com/releases/2007/03/070330185008.htm>.
National Institute of Standards and Technology (NIST). (2007, April 1). Cells Selectively Absorb Short Nanotubes. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2007/03/070330185008.htm
National Institute of Standards and Technology (NIST). "Cells Selectively Absorb Short Nanotubes." ScienceDaily. www.sciencedaily.com/releases/2007/03/070330185008.htm (accessed September 2, 2014).

Share This




More Matter & Energy News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins