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The newspaper of The Johns Hopkins University June 23, 2008 | Vol. 37 No. 38
Health, Environment Are Focus of Latest NanoBio Seed Grants

By Mary Spiro
Institute for NanoBioTechnology

Little is known about how engineered nanomaterials and nanoparticles impact human health and the environment. Particles at the scale of one-billionth of a meter — so small they can slip across the blood-brain barrier — pose many questions about the safety of nanotechnology used in products consumed and used by humans. The Institute for NanoBioTechnology at Johns Hopkins recently awarded $100,000 to fund research projects that seek to answer these questions. Four $25,000 seed grants were given to multidisciplinary research teams to fund pilot projects across Johns Hopkins.

Jon Links, professor at the Bloomberg School of Public Health and INBT's director of health and environment research, says that risk assessment performed in tandem with research into beneficial applications will help researchers make better decisions about how nanotechnology is used in the future.

"The history of technological research and development is full of examples of unrecognized risks to health and the environment. Chlorofluorocarbons and asbestos are examples," Links said. "It is imperative to study potential risks to human health and the environment hand in hand with benefit-driven research and development. Doing so provides the best chance to minimize risk, because risk assessment can inform research and development at an early stage, leading to alternative pathways."

Nanoparticles made of silica, for example, can be used to deliver pharmaceuticals. But despite the potential benefits, scientists don't have much information on what happens to these particles after they have offloaded their cargo. Principal investigators from the schools of Public Health and Engineering plan to use a protein to measure the toxicity of silica nanoparticles in the brain cells of rodents.

Tomas Guilarte, professor of environmental health sciences in the Bloomberg School and a co- investigator on this study, said, "There is a tremendous interest in using nanomaterials in various aspects of medicine, including delivery of drugs to the brain. However, the possibility that the nanomaterial itself produces brain injury has not been evaluated."

In another proposed study, collaborators from Public Health and Engineering will measure how the shape, size and function of engineered silica-silicone hybrid nanomaterials affect cellular uptake and response using advanced methods for cell imaging and biomarker assessment. This research also will address questions related to dose and exposure.

Howard Katz, professor of materials science and engineering in the Whiting School, said, "Once these particles reach cells, it is important to know whether they penetrate into cells, whether cells survive this penetration and whether the biochemistry inside these cells is altered."

"These methods will permit us to visualize where nanomaterials are located in cells, and the nature of any response by these cells," added Ellen Silbergeld, professor of environmental health sciences in the Bloomberg School.

Multiwalled carbon nanotubes are commonly used engineered nanoparticles that have been exploited for their exceptional strength as well as their chemical, optical and electrical properties. But these particles also are known to bind toxic heavy metals. If the nanotubes wind up in the food chain, they could deposit toxic metals in the stomachs of animals or humans. The fate of these metals will be examined in an in vitro study developed by researchers from the schools of Arts and Sciences, Engineering and Public Health.

"Given their extremely high surface area-to-mass ratios, small amounts of carbon nanotubes have the potential to transport relatively large amounts of adsorbed toxins," said William Ball, professor of geography and environmental engineering in the Whiting School. "In this way, the carbon nanotubes could effectively act as 'Trojan horses' that may bring toxic contaminants to locations that they may not otherwise reach."

Nanoparticles made of silver oxide, silver nitrate, silver chloride and titanium dioxide can be found in many household products, from the coatings on washing machines to personal care items. These particles may enter the ecosystem through wastewater and affect aquatic life. Investigators from Public Health, Arts and Sciences and Engineering will track those particles to see if any show up in oysters commercially harvested from the Chesapeake Bay.

"In the water, engineered nanoparticles can alter oyster immune defense mechanisms, making them more susceptible to oyster diseases," said Thaddeus Graczyk, associate professor in the Bloomberg School. "As oysters are predominantly consumed raw, nanoparticles recovered from the water by oysters and retained in their tissue will enter the human food chain."

These pilot projects represent some of the ongoing research at the Institute for NanoBioTechnology, which seeks to balance benefit-driven applications of nanotechnology with risk assessment. Findings from these investigations are expected to have policy implications for the use of nanoparticles. "Since inaccurately perceived risks by the public and legislators can slow development and adoption of beneficial technologies, accurate assessment and timely dissemination of the actual risks is becoming more and more critical," Links said. "Relatively little is known about the potential ecologic and human toxicity of nanomaterials, so INBT's pilot project program is critical."

For a complete list of pilot programs and their research teams, go to: t-nanobio-seed-grants/2008/06


INBT Grant Proposal Service

INBT offers help to those wishing to submit a nanobiotechnology-related grant proposal. Seed grants awarded by INBT must have more than one principal investigator, and principal investigators must be from different schools or departments. To learn more about INBT's grant proposal service, contact Sue Porterfield at or 410-516-3423. To learn more about funding opportunities through INBT, go to


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