New center studies nanoparticles in the environment

Are nanoparticles – atomic-scale ingredients in products ranging from sunscreen to clothing – harmful? To answer that question, says UWM toxicologist Rebecca Klaper, scientists must first figure out what these invisible bits of material do once they enter a living cell.

“We know there are behavioral and physiological differences that result from exposure to certain nanoparticles,” says Klaper, an associate professor of freshwater sciences. “The question is, what is changing on the molecular level?”

A collaborative research project involving five Midwestern institutions, including UWM, is taking an interdisciplinary look at the interactions of nanoparticles within living tissue.

Backed by a $1.75 million grant from the National Science Foundation’s Division of Chemistry, the group also includes UW-Madison, the University of Illinois, the University of Minnesota, Northwestern University and the Pacific Northwest National Laboratory. Collectively, they form the NSF Center for Sustainable Nanotechnology.

After three years, the center could be eligible for phase II grants that provide up to $40 million over 10 years.

Nanoparticles are bits of matter only a few billionths of a meter in size. Their unique properties make them valuable in many new technologies, such as fuel cells.

The center’s study will make and then investigate the molecular interaction of nanoparticles of various sizes, shapes and chemical structures with organisms. Using the single-cell Shewanella oneidensis and a tiny water flea called Daphnia as models, scientists will track the particles with high-resolution imaging, while also tracing the biomarkers of the animal that indicate a genomic pathway has been interrupted.

Another goal is to determine how the structure of the nanoparticle affects biological cells. Altering the surface chemistry of the particle could make them more or less toxic.

“We want to know where they are going inside of an organism – hopefully in real time – and then tie that information to molecular mechanisms occurring, such as protein changes,” says Klaper.

Physiological indicators of harm would be changes in the animal’s reproduction, metabolism, or growth and development. One at-risk population are workers who make these particles, she says, because they are most likely to inhale them.

The work will ultimately contribute to the development of nanomaterials with reduced environmental impact.

Klaper is becoming a recognized voice in research on the environmental impacts of engineered nanoparticles. As a member of a National Research Council panel, she briefed the Environmental Protection Agency and congressional committees on the topic earlier this year.