Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Cells selectively absorb short nanotubes

Abstract:
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.*

*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 on-line : 20 March 2007.

Cells selectively absorb short nanotubes

MD | Posted on March 30th, 2007

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."

####

For more information, please click here

Contacts:
Michael Baum

301-975-2763

Copyright © National Institute of Standards and Technology (NIST)

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Discoveries

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Announcements

Cryo-electron microscopy achieves unprecedented resolution using new computational methods March 25th, 2017

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Safety-Nanoparticles/Risk management

NIST updates 'sweet' 1950s separation method to clean nanoparticles from organisms January 27th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Investigating the impact of natural and manmade nanomaterials on living things: Center for Environmental Implications of Nanotechnology develops tools to assess current and future risk January 9th, 2017

First time physicists observed and quantified tiny nanoparticle crossing lipid membrane November 7th, 2016

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project