Explore Magazine Volume 6 Issue 1


         As chief of emergency medicine at Shands at UF, Dr. David Seaberg knows all too well the frustration of losing a drug overdose patient.
         Despite new antidotes and techniques, Seaberg still loses some patients to certain potent drugs, especially heart medications.
         “Their heart slows down, their blood pressure goes down, it’s pretty ominous,” Seaberg says of these overdoses, typically the result of suicide attempts. “We can’t do a lot for those patients when they start going bad.”
         Estimated to cause 300,000 deaths annually nationwide, overdoses are the focus of a new University of Florida research project that attacks the problem with an entirely new approach. Researchers are seeking to develop tiny “nanoparticles” that, when injected into the bloodstream, find and capture the drugs before they damage internal organs. While years away from clinical trials, the goal is not unrealistic. Already, Charles Martin, a UF professor of chemistry and one of a team of researchers on the project, has created tiny tubular particles that, when dispersed in water, seek out and cling to certain types of target molecules.
         The overdose project exemplifies what many researchers view as one of the next big frontiers in scientific inquiry: nanotechnology. Ask scientists or engineers what is meant by the term and you’ll get a host of different answers. But, generally, nanotechnology involves the manipulation of almost unimaginably small amounts of matter — handfuls of atoms or molecules — to create tiny materials or machines.
         The endeavor has stirred intense interest because its potential applications are staggering. Scientists talk about developing machines that could seek out and destroy cancer cells, microscopic yet ultrapowerful computer chips and “swarms” of tiny mechanical insects that hunt down agricultural pests. Excited by the potential, the federal government has made an estimated $1 billion available in federal nanoscience or nanotechnology grants.
         UF is heavily involved on several fronts. At least 60 faculty members and 100 graduate students in engineering, chemistry, physics and many other disciplines are working on dozens of nanotechnology research projects. Spurred by two engineering faculty members, the university is seeking funding for a Multidisciplinary Nanosystems Facility, a $26.2 million project that would bring together researchers from many disciplines in a 90,000-square-foot “nanofabrication” building. With $8 million in support from the UF Research Foundation and the colleges of Engineering and Liberal Arts and Sciences, officials also recently launched the UF Institute for Nanoscience and Nanotechnology to provide equipment, space and support for faculty doing nanotechnology research.

The Lure Of “Smart” Particles
         Nanotechnology research at UF ranges from the basic to the applied, with several stops in between. The more basic research seeks to tease out how materials behave at a scale measured in nanometers, or one billionth of a meter. This mysterious realm between the atomic level and the bulk level is where a material actually develops its unique properties and structure.
         Gold offers a good example, says Martin, the chemistry professor. “Scientists know essentially everything about bulk samples of gold, its density, melting point and electrical conductivity are examples. We also know essentially everything about individual gold atoms, but somewhere between these two extremes — the atomic and the bulk – every property of gold changes. This ‘no-man’s land’ is the realm of nanomaterials.”
         UF physicists and chemists have several projects probing basic nanoscience. In one, a group of physicists and chemists are studying the nanostructures of semiconductors, examining phenomena with names like “quantum wires” and “quantum wells.” These are layers of composite structure 10 nanometers wide where electrons become trapped. “By studying the disorder of the system, we can better understand transport and mobility of the electrons through these nanostructures,” says C.R. Bowers, associate professor of chemistry.
         For the layman, however, the more approachable work lies in the applied areas. Much of this research at UF is taking place in biomedicine, where biology and technology are offering many new opportunities.

         “A revolution has occurred in biology that has allowed us to understand cellular mechanisms at a much more minute and precise level than we ever did in the past,” says Chris Batich, a professor of materials science and engineering and director of the UF Biomedical Engineering Graduate Program. “Now, going beyond that understanding, we’re learning how to make tools and machines that will interact and control things at that level.”
         Although efforts are diverse, a common feature among several UF projects is a focus on “nanoparticles,” some with diameters thousands of times smaller than the diameter of the human hair. The overdose research, which involves faculty from chemistry, pharmacy and the Engineering Research Center for Particle Science and Technology, is just starting, but other efforts are further along — particularly some of UF chemistry Professor Weihong Tan’s research.
         One of Tan’s projects is to make dye-filled silica particles or “microspheres” that bind to diseased or cancerous cells. The dye alerts researchers working with powerful microscopes to the presence of the cells, considerably accelerating their work. Tan recently published results demonstrating that the dye-filled spheres would bind with leukemia cells.
         The obvious next step, he says, is to make spheres capable of delivering therapeutic drugs to diseased cells. “It’s not science fiction, but it’s not reality — yet,” he says.
         Tan is also working on a “gene chip” that would help researchers identify crucial proteins and on tiny probes that physicians may one day insert into individual cells to test for disease.
         Other particle-based research at UF is more closely tied to clinical treatment. In one project, two mechanical engineering researchers have developed a device that will help researchers understand and predict how insulin molecules will behave in no- and low-humidity settings. Such a device is needed to test forms of inhalable, “aerosolized” insulin, which is widely expected to replace injected insulin for many diabetics in the near future.
         “Instead of giving yourself a shot numerous times each day you can create this aerosol cloud in a container and inhale it,” said W. Gregory Sawyer, an assistant professor of mechanical engineering who is collaborating on the project with Jim Klausner, a professor of mechanical engineering.

Nanotechnology: The Natural Way
         While some particle research at UF applies nanotechnology to biology, another approach seeks to mimic biology itself. One project that captures the essence of this “biomimetic” approach is a materials science and engineering effort to create artificial bone.
         Because bone is a living tissue, the body has a remarkable ability to repair fractures. However, for major problems such as a tumor or a severe break, surgeons may have to do a bone graft. The standard is to use a bone fragment taken from the patient’s hip or rib, called an autograft. However, the procedure requires two surgeries and a long and painful recovery. Allografts, when cadaver bones are used, eliminate the second surgery but risk rejection and transmission of disease. Metal implants, meanwhile, do not have the combination of strength and flexibility that make bone such a tough material.
         Materials science and engineering Assistant Professors Elliot Douglas and Laurie Gower are attempting to provide another alternative: bone created from its basic molecular building blocks. Put another way, the researchers hope to actually mimic the natural “biomineralization” processes that cells use when forming bone. The first step is to coax collagen fibrils, the primary protein in bone, to self-assemble into parallel rows. The second step is to infiltrate the matrix with nanoscopic crystals to build a nanostructured composite that mimics bone.
         The difficulties are many. For example, the biological processes that go into bone growth are not well understood, leaving the researchers without a good map. Ironically, the researchers’ work may actually shed light on the natural process.
         “We suspect that, because what we’re doing could be similar to the biological process, there is the potential to fabricate a composite with a nanostructure that simulates that of bone,” Gower says. “And this capability could provide important clues toward solving the mystery of bone formation.”

MEMS And Jet Engines
         But nanotechnology is not just about biotechnology. At UF, researchers also are working on projects with applications in defense, aerospace and the automobile industry. Many revolve around a close cousin of nanotechnology: Microelectromechanical Systems, or MEMS. Just as computer chips miniaturized transistors, MEMS miniaturizes machines, creating microscopic valves, motors, pumps and microphones. MEMS devices are already found in printer heads, disposable blood pressure analyzers and automobile air bags, where tiny accelerometers trigger the bags to expand when a collision occurs.
         As founders of the Interdisciplinary Microsystems Group, a multidisciplinary MEMS-based research group, Mark Sheplak and Toshi Nishida are working on several more applications. Among other projects, Sheplak, an assistant professor of aerospace engineering, mechanics and engineering science, and Nishida, an associate professor of electrical and computer engineering, are designing tiny microphones that could be used in jet engine construction to pinpoint the source of noise, helping builders make the engines quieter. The system would replace large microphone arrays that are expensive and cumbersome.
         “We hope to get rid of the large equipment and process the noise very close to the source,” Sheplak says.
         With the support of Paul Thompson, associate dean of engineering and interim associate vice president for research, Sheplak, Nishida and two colleagues proposed the idea for the Multidisciplinary Nanosystems Facility, which would include a 15,000-square-foot centralized, universitywide nanofabrication facility surrounded by multidisciplinary laboratories. They say the facility will boost nanotechnology and MEMS research by bringing together faculty from different disciplines and providing space and equipment for the research.
         “UF efforts in nanotechnology would be accelerated tenfold by the new facility,” Nishida said.
         Ranked 42nd on the state’s list of major building projects, the facility is several years from construction, but it may move up as state officials become convinced of the importance of nanotechnology to the 21st-century economy.

         And there are other indicators of UF’s commitment to nanotechnology. This fall, faculty submitted seven major proposals to the National Science Foundation, which recently made $74 million available through its Nanoscale Science and Engineering Initiative. UF’s Institute for Nanoscience and Nanotechnology, meanwhile, is still in the formative stages but is anticipated to play a major role in fostering and sustaining nanotechnology research.
         “Like molecular biology or information technology, nanotechnology will raise our technological capabilities to a new level, improving health care, increasing our standard of living and driving further economic xpansion,” says Win Phillips, UF vice president for research and dean of the Graduate School. “UF has the right ingredients to become a leader in this area, and the Institute for Nanoscience and Nanotechnology is a solid first step toward this goal.”



C.R. Bowers
Associate Professor, Department of Chemistry“(352) 846-0839

Elliot Douglas
Assistant Professor, Department of Materials Science and Engineering
(352) 846-2836

Laurie Gower
Assistant Professor, Department of Materials Science and Engineering
(352) 846-3336

Charles Martin
Professor, Department of Chemistry
(352) 392-1597

Toshi Nishida
Associate Professor, Department of Electrical & Computer Engineering
(352) 392-6774

Mark Sheplak
Assistant Professor, Department of Aerospace Engineering,
Mechanics and Engineering Science
(352) 392-3983

Weihong Tan
Assistant Professor, Department of Chemistry
(352) 392-0541

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