Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Nanoparticle toxicity doesn't get wacky at the smallest sizes: Big and small nanoparticles affect most genes similarly

Abstract:
The smallest nano-sized silica particles used in biomedicine and engineering likely won't cause unexpected biological responses due to their size, according to work presented today. The result should allay fears that cells and tissues will react unpredictably when exposed to the finest silica nanomaterials in industrial or commercial applications.

Nanoparticle toxicity doesn't get wacky at the smallest sizes: Big and small nanoparticles affect most genes similarly

Chicago, IL | Posted on February 14th, 2009

Nanotoxicologist Brian Thrall and colleagues found that, mostly, size doesn't matter, by using total surface area as a measure of dose, rather than particle mass or number of particles, and observing how cultured cells responded biologically.

"If you consider surface area as the dose metric, then you get similar types of responses independent of the size of the particle," said Thrall, a scientist at the Department of Energy's Pacific Northwest National Laboratory in Richland, Wash. "That suggests the chemistry that drives the biological responses doesn't change when you get down to the smallest nanoparticle."

Nanoparticles are materials made up of spherical particles that are on average 100 to 1,000 times smaller than the width of a human hair. They are being used in tires, biomedical research, and cosmetics. Researchers are exploring these tiny spheres because their physical and chemical properties at that size offer advantages that standard materials don't, such as being able to float through blood vessels to deliver drugs.

But whether these materials are safe for human consumption is not yet clear. Previous work suggested in some cases, nanoparticles become more toxic to cells the smaller the particles get.

Thrall presented this toxicology data on amorphous silica nanoparticles today at the 2009 American Association for the Advancement of Science's annual meeting. He also presented data on which cellular proteins the nanoparticles use to get inside cells.

One difficulty in measuring toxicity is that not everyone agrees which kind of dose unit to compare. Some researchers measure the dose by total weight, some by the number of particles. Neither method distinguishes whether a nanomaterial's toxicity is due to the inherent nature of the material or the particle size under scrutiny.

"Different dose metrics give different impressions of which particles are more toxic," he said.

To find out, Thrall and his colleagues at PNNL measured the dose at which the particles caused a biological response. The biological response was either death of the cell, or a change in which genes the cell turned on and off. They found that when calculating doses by particle number or mass, the amount needed to generate a biological response was all over the map.

They found that the best way to pinpoint how toxic the particles are to cells was to calculate the dose based on the total surface area of the nanomaterial. Only when they considered the surface area of the dose could they predict the biological response.

And the biological response, they found, was very similar regardless of the size of the nanoparticles. Inside cells, some genes responded to nanoparticles by ramping up or down. More than 76 percent of these genes behaved the same for all nanoparticle sizes tested. This indicated to the researchers that, for these genes, the nanoparticles didn't pick up weird chemical properties as they shrunk in size.

"The big fear is that you'd see unique biological pathways being affected when you get down to the nanoscale. For the most part, we didn't see that," said Thrall.

However, the team found some genes for which size did matter. A handful of genes, these fell into two categories: smaller particles appeared to affect genes that might be involved in inflammation. The larger particles appeared to affect genes that transport positively charged atoms into cells. This latter result could be due to metals contaminating the preparation of the larger particles, Thrall suggested.

Overall, the results contribute to a better understanding of what goes on at the nanoscale.

Reference: Brian Thrall, Systems Toxicology of Engineered Nanomaterials in seminar titled Driving Beyond Our Nano-Headlights? Saturday, February 14, 8:30 am - 11:30 am in conference room Hyatt Regency, Crystal Ballroom B, at the American Association for the Advancement of Science 2009 Annual Meeting, Chicago, Ill.

This work was supported by Laboratory-Directed Research and Development and then the National Institutes of Health.

####

About DOE/Pacific Northwest National Laboratory
Pacific Northwest National Laboratory is a Department of Energy Office of Science national laboratory where interdisciplinary teams advance science and technology and deliver solutions to America's most intractable problems in energy, national security and the environment. PNNL employs 4,200 staff and has an $850 million annual budget. Ohio-based Battelle has managed PNNL since the lab's inception in 1965.

For more information, please click here

Contacts:
Mary Beckman

509-375-3688

Copyright © DOE/Pacific Northwest National Laboratory

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

News and information

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Techís Contribution Includes Litenís Knowhow in Magnetic Materials and Simulation And Letiís Expertise in Wide-bandgap Semiconductors October 20th, 2017

Laboratories

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Rice U. lab surprised by ultraflat magnets: Researchers create atom-thick alloys with unanticipated magnetic properties October 13th, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Discoveries

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Announcements

Creation of coherent states in molecules by incoherent electrons October 21st, 2017

Novel 'converter' heralds breakthrough in ultra-fast data processing at nanoscale: Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster October 20th, 2017

Strange but true: turning a material upside down can sometimes make it softer October 20th, 2017

Leti Coordinating Project to Develop Innovative Drivetrains for 3rd-generation Electric Vehicles: CEA Techís Contribution Includes Litenís Knowhow in Magnetic Materials and Simulation And Letiís Expertise in Wide-bandgap Semiconductors October 20th, 2017

Safety-Nanoparticles/Risk management

Do titanium dioxide particles from orthopedic implants disrupt bone repair? September 16th, 2017

Tests show no nanotubes released during utilisation of nanoaugmented materials June 9th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

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

Events/Classes

Nanometrics Announces Preliminary Results for the Third Quarter of 2017: Quarterly Results Impacted by Delays in Revenue Recognition on Multiple Systems into Japan October 12th, 2017

More 22 of 59,885 Print all In new window Leti to Present Update of CoolCube/3DVLSI Technologies Development at 2017 IEEE S3S: Future Developments and Tape-Out Vehicles to Be Presented during Oct. 17 Workshop October 12th, 2017

Arrowhead Pharmaceuticals to Present Preclinical Data on ARO-AAT at The Liver Meeting(R) October 10th, 2017

Arrowhead to Present at Chardan Gene Therapy Conference October 3rd, 2017

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