Scientists to Test Toxicity of Nanomaterials

Materials science is getting small – on the order of the atomic scale. Fibers, spheres, crystals and films 1,000 times thinner than human hair hold the promise of producing faster cars and planes, more powerful computers and satellites, better microchips and batteries. Inventors even plan to use nanomaterials to make artificial muscle, military armor and medicines. Nanomaterials can already be found in sunscreens, concrete, tennis rackets, car bumpers and wrinkle-resistant clothes. But are they safe?

Through a new four-year, $1.8-million National Science Foundation grant, Brown University scientists are testing a variety of nanomaterials to see how they interact with human and animal cells. The aim: Find out which sizes, shapes, compounds and coatings damage or kill cells. That information can be used to manufacture non-toxic types.

“The question isn’t whether nanomaterials are good or bad,” said Robert Hurt, a Brown professor of engineering and the lead investigator on the project. “The question is which are toxic? Under what conditions? And can we make and purify them in different ways to avoid toxicity – to make ‘green’ nanomaterials?”

The grant supports important early work at Brown in an emerging field of environmental health.

According to the Institute of Medicine, the federal government last year invested nearly $1 billion in nanotechnology, yet little is known about how engineered nanoparticles affect human health. To fill the knowledge gap, the National Science Foundation and other government agencies are spending a total of $38.4 million this fiscal year in research on the environmental, health and safety aspects of nanomaterials. A journal, Nanotoxicology, was launched this year along with the first database of research on the biological and environmental impacts of nanoparticles.

Hurt said nanoparticles have captured the imaginations of materials scientists and chemists because they have desirable properties such as extreme strength or outstanding electrical or thermal conductivity. However, a small number of animal studies show that some nanomaterials can damage brain or lung tissue or block blood flow.

To better understand which materials are toxic and which are safe, the Brown project takes a multidisciplinary approach.

In the Division of Engineering, Hurt and colleague Gregory Crawford are creating carbon nanotubes, fibers and spheres – all popular in electronics – by the billions. Crawford is arranging the materials on glass slides based on size, shape and chemical composition, a novel “chip” platform that will allow for precise, systematic testing.

The chips will then head to Jeffrey Morgan and Agnes Kane at Brown Medical School.

Morgan, a biologist and tissue engineer, will test the materials’ affect on lab-grown human skin cells. Kane, a pathologist, will test the materials on macrophages, cells that defend against foreign invaders, culled from mice. Both will check to see if cells die, incur DNA damage or trigger exaggerated immune defenses.

Phil Brown, professor of sociology and environmental studies, will explore the social and ethical implications of nanotechnology and how to communicate health exposure risks to the public, including faculty and students who work with nanomaterials in campus labs.

Source: Brown University

Related stories:

Researchers create mercury-absorbent container linings for broken CFLs
With rising energy prices and greater concern over global warming, compact fluorescent lamps (CFLs) are having a successful run. Sales of the curlicue, energy-sipping bulbs, which previously had languished since they were introduced in the United States in 1979, reached nearly 300 million last year. Experts expect that figure to rise steeply by 2012, when a federal law requiring energy-efficient lighting goes into effect.
Scientists learning to create nanomaterials based on micro-algae patterns
Researchers at the Georgia Institute of Technology have developed a technique to study how unicellular micro-algae, known as diatoms, create their complex cell walls. Researchers hope to learn how diatoms assemble these nanometer-patterned, intricate micro-architectures to find better methods for creating nanomaterials in the laboratory.
Brown Engineers Use DNA to Direct Nanowire Assembly and Growth
A small but growing number of engineers are using nature’s engineer – DNA – to create nanomaterials that can be used in everything from medical devices to computer circuits. A team from Brown University and Boston College is the first to use DNA to direct construction and growth of complex nanowires. Their work appears in Nanotechnology.

Problem: implant infection, solution: nanotech surfaces
Orthopaedic implants help millions of Americans stay active. But these medical devices are prone to infection, forcing patients back to surgery for repair or replacement. Now, for the first time, a team of engineers has shown that zinc or titanium oxide nanosurfaces can reduce the presence of bacteria, a technique that can be applied to implants to reduce the number of these costly and debilitating infections.
Carbon nanotube building blocks open up possibilities for advanced electronics
A new method to systematically modify the structure of single-walled carbon nanotubes could expand their electronic properties and open the path to nano-electronics.
'Nanosculpture' could enable new types of heat pumps, energy converters
A new technique for growing single-crystal nanorods and controlling their shape using biomolecules could enable the development of smaller, more powerful heat pumps and devices that harvest electricity from heat.
Improving Quantum Dot Synthesis
Materials researchers at the National Institute of Standards and Technology have developed a simplified, low-cost process for producing high-quality, water-soluble quantum dots for biomedical applications. By using a laboratory microwave reactor to promote the synthesis of the widely used nanomaterials, the recently published NIST process avoids a problematic step in the conventional approach to making quantum dots, resulting in brighter, more stable dots.
A better image for plastic solar cells
A new way to help technologists develop efficient and inexpensive plastic electronic devices, such as plastic solar cells and a new type of transistor was showcased by physicist Andrea Liscio, who is supported by the European Science Foundation, at the EMRS (European Material Research Society) Spring Meeting held in Strasbourg, France at the end of May.

News discussion:

Nanotechnology news