Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST technique controls sizes of nanoparticle clusters for EHS studies

03.02.2011
The same properties that make engineered nanoparticles attractive for numerous applications—small as a virus, biologically and environmentally stabile, and water-soluble—also cause concern about their long-term impacts on environmental health and safety (EHS).

One particular characteristic, the tendency for nanoparticles to clump together in solution, is of great interest because the size of these clusters may be key to whether or not they are toxic to human cells. Researchers at the National Institute of Standards and Technology (NIST) have demonstrated for the first time a method for producing nanoparticle clusters in a variety of controlled sizes that are stable over time so that their effects on cells can be studied properly.*

In their tests, the NIST team made samples of gold, silver, cerium oxide and positively-charged polystyrene nanoparticles and suspended them separately in cell culture medium, allowing clumping to occur in each. They stopped the clumping by adding a protein, bovine serum albumin (BSA), to the mixtures. The longer the nanoparticles were allowed to clump together, the larger the size of the resulting cluster. For example, a range of clustering times using 23 nanometer silver nanoparticles produced a distribution of masses between 43 and 1,400 nanometers in diameter. Similar size distributions for the other three nanoparticle types were produced using this method.

The researchers learned that using the same "freezing times"—the points at which BSA was added to halt the process—yielded consistent size distributions for all four nanoparticle types. Additionally, all of the BSA-controlled dispersions remained stable for 2-3 days, which is sufficient for many toxicity studies.

... more about:
»BSA »NIST »blood cell »human cell »silver ions

Having successfully shown that they could control the production of nanoparticle clumps of different sizes, the researchers wanted next to prove that their creations could be put to work. Different-sized silver nanoparticle clusters were mixed with horse blood in an attempt to study the impact of clumping size on red blood cell toxicity. The presence of hemoglobin, the iron-based molecule in red blood cells that carries oxygen, would tell researchers if the cells had been lysed (broken open) by silver ions released into the solution from the clusters. In turn, measuring the amount of hemoglobin in solution for each cluster size would define the level of toxicity—possibly related to the level of silver ion release—for that specific average size.

What the researchers found was that red blood cell destruction decreased as cluster size increased. They hypothesize that large nanoparticle clusters dissolve more slowly than small ones, and therefore, release fewer silver ions into solution.

In the future, the NIST team plans to further characterize the different cluster sizes achievable through their production method, and then use those clusters to study the impact on cytotoxicity of coatings (such as polymers) applied to the nanoparticles.

* J.M. Zook, R.I. MacCuspie, L.E. Locascio, M.D. Halter and J.T. Elliott. Stable nanoparticle aggregates/agglomerates of different sizes and the effect of their size on hemolytic cytotoxicity. Nanotoxicology, published online Dec. 13, 2010 (DOI: 10.3109/17435390.2010.536615).

Michael E. Newman | EurekAlert!
Further information:
http://www.nist.gov

Further reports about: BSA NIST blood cell human cell silver ions

More articles from Life Sciences:

nachricht When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie

nachricht WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>