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Nanobiotechnology Researcher Nancy Xu Elected AAAS Fellow

nancy-xu-researchXu (seated) with a member of her research group, Kerry Lee.

X. Nancy Xu, professor of chemistry and biochemistry at Old Dominion, has been elected a Fellow of the American Association for the Advancement of Science (AAAS), one of the highest honors a scientist can receive.

The award citation states that the distinction, which is bestowed upon AAAS members by their peers, was given to Xu "for distinguished contributions to the fields of nanobiotechnology and ultrasensitive bioanalysis, including single nanoparticle optics, nanobiosensors, single molecule detection and single living cell imaging."

Xu, who leads one of the largest research groups at ODU, has received $3.5 million in recent grants from the National Science Foundation and National Institutes of Health. Her work focuses on the development and application of cutting edge bio- and nanotechnologies as well as ultrasensitive analytical methodologies to address fundamental and practical questions in chemical, biochemical and biomedical research. In particular, she studies chemical and biological reactions in real time at the single-molecule level.

Over the past decade she has developed a reputation as a problem solver and innovator in the field of nanomedicine. She has been recognized for her achievements by two of NASA's NANO 50 awards and by the National Cancer Institute in its publication "Mission to the Inside of a Living Cell." A DNA biosensor she developed has received a worldwide patent and she has three pending U.S. patents in the field of nanobiotechnology.

Xu received a Ph.D. from the University of Mississippi in 1992 and pursued postdoctoral research at the University of Texas, Austin, and Ames Lab-Iowa State University before joining ODU in 1998. She has published 45 peer-reviewed journal articles, five book chapters and a book. Her papers are widely cited and highlighted. She has presented more than 120 papers (among them 53 invited papers) at national and international conferences, and she has delivered nearly 50 invited seminars at universities across the nation and around the world.
Xu will receive the certificate and rosette of an AAAS Fellow in February at the annual meeting of the association in Vancouver, British Columbia.

Two other members of the College of Sciences faculty are AAAS Fellows; both are in the Department of Ocean, Earth and Atmospheric Sciences. Cynthia Jones, Eminent Scholar and professor, was elected in 2009. Larry Atkinson, Eminent Professor and the Samuel M. and Fay L. Slover Professor of Oceanography, is a longtime holder of the distinction. Altogether, ODU faculty members have been elected to approximately 80 Fellow positions in societies, academies, institutes and other organizations in the United States and other countries.

Research of the Xu group resulted earlier this year in a new photostable optical nanoscopy technique that was reported in the cover article of the journal Nanoscale. This technique, which could promote the discovery of new therapeutic drugs, allows the real-time mapping of molecular interactions at the cellular level with 1.2-nanometer resolution.

Overall, the Xu research group has looked into a possible "stealth" quality for single-nanoparticle probes of living cells or for similar nanoparticle vehicles that can deliver medicine into the cells. In other words, they have been studying means by which nanoparticles can penetrate cells and accomplish their mission without harming the cells or being ejected by an efflux pumping mechanism that utilizes membrane transporters. This mechanism naturally targets foreign objects for ejection from cells.

The research group has reported success employing flecks of precious metals no longer than one-millionth of a meter as reliable probes of living cells and embryos. In this process, Xu and her colleagues have found ways to synthesize and purify silver and gold nanoparticles that will stay stable - one size, or monodisperse - over an extended period. They have also reported breakthroughs in the way they image and characterize nanoparticles using dark-field optical microscopy and spectroscopy.

The small size of the nanoparticles that have been created enables them to penetrate living organisms, but the surface area is large relative to the overall size, and this allows the particles to perform better in optical sensing and to carry a larger payload of drugs. The rainbow colors of these nanoparticles also contribute to their usefulness as probes and sensors.

Not only has the group's research advanced techniques for nanoparticle delivery of drugs, but it also has found that the nanoparticles alone, without a drug payload - particularly the large-size silver nanoparticles - may affect certain cellular functions. This means that the nanoparticles themselves could be used as nanomedicines, say, to kill cancer cells.
The tradition of AAAS Fellows began in 1874. Currently, members can be considered for the rank of Fellow if nominated by the steering groups of the association's 24 sections, or by any three Fellows who are current AAAS members, so long as two of the three sponsors are not affiliated with the nominee's institution, or by the AAAS chief executive officer.
Each steering group then reviews the nominations of individuals within its respective section and a final list is forwarded to the AAAS Council, which votes on the aggregate list.

AAAS was founded in 1848 and is the world's largest general scientific society, and publisher of the journal Science (www.sciencemag.org).

By Jim Raper