Think of it as a modern-day version of the canary in a coal mine—
living tissue interfaced with microchip circuits that can function as an early-warning system for chemical or biological warfare. Biomedical engineer Steve DeWeerth has been working on the biosensor concept for years. Now he’s turning it up a notch.

This kind of research is why biomedical engineering exists,” says DeWeerth, an expert in computation and neural systems in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech/Emory. “Blending medicine and engineering allows us to do things that would be impossible through either specialty alone.”

DeWeerth is developing two types of biosensing devices, one connecting muscle cells to electronic circuits to detect effects of chemical or biological agents, and the other using “cycling probe” technology to match the DNA fingerprint in air particles or fluids to known viruses or bacteria.

“The first line of defense against biological and chemical warfare is your body,” says DeWeerth. “When you get sick, you know there’s a problem. But we don’t want people to get sick, we want devices to get sick. It’s like a tiny smoke alarm.” DeWeerth expects that either device could be ready for use as a building sensor in the near future.

Devices like these illustrate the clear relevance of “translational” research, a new buzzword for research easily translated into benefit for people—and a concept that has been the compelling force behind biomedical engineering since its very beginning. You can hear the excitement it generates in DeWeerth’s immodest but animated view of his department’s mission: “In all honesty,” he says earnestly as he woos a faculty recruit, “we’re trying to change the world!”

Immodesty aside, in its five short years of existence, the Coulter Department of Biomedical Engineering (BME) has indeed been on a breathtakingly rapid rise toward the top of its field––accumulating major funding, top-notch (and enthusiastic) faculty, brilliant students, and sparkling new facilities. BME also has earned sixth-place ranking from US News & World Report, surpassing a number of well-respected and established programs.

Despite these early successes, BME faculty say they plan to stop at nothing short of creating the gold standard of research and education in biomedical engineering. The key to creating groundbreaking biomedical technology within the next 100 years, they believe, is to obliterate forever the rigid distinction between engineering and medicine and establish an entirely new culture of scientists. This new breed of scientists will be comfortable and conversant in both medicine and engineering, applying engineering principles to medicine and using living molecules to design replacements for damaged organs or tissues.

“Thirty years ago, if someone had said ‘bioengineering’, you might have thought ‘biotechnician’ and pictured a guy who fixes your TV set in the hospital,” quips DeWeerth, “just as 100 years ago, people would have asked, ‘What’s electrical engineering?’ Just look at the way doctors were trained at the beginning of the past century. Fifty years from now, we will reflect on the way physicians and engineers were trained separately and see the distinction as quaint. Biomedical problems need a common solution that uses the knowledge of both medicine and engineering.” (BACK TO TOP)

Pivotal relationships

One person who has already seen a great deal of blurring of the distinction between medicine and engineering in a relatively short time is former BME chair Don Giddens. A 30-year veteran of Tech and a former dean of engineering at Johns Hopkins, Giddens has been a fulcrum in the relationship between Emory and Tech for more than 15 years. Since that time, he has seen a program transpose into a department, propelled by major funding from the Coulter and Whitaker foundations (see timeline, page 22). Those gifts are providing precious space to make room for an even more priceless commodity in the form of faculty and students.

Giddens says another architectural linchpin of the department is the Georgia Research Alliance (GRA), a partnership of Georgia’s research universities, business community, and state government created in 1990. Giddens, who is a GRA Eminent Scholar, says the Emory-Tech collaborations fit perfectly into the GRA’s model of university partnership, as does their heavy emphasis on translational research and research commercialization. He adds that the GRA recently attracted another eminent scholar to BME, Xiaoping Hu, a pioneer in functional magnetic resonance imaging (MRI), who will head a new biomedical imaging technology center at Emory. (BACK TO TOP)

Imagine these images

The new GRA scholar will join an already strong and growing medical imaging group that includes Allen Tannenbaum, an engineer/mathematician whose inventions are designed to make diagnostic methods less invasive and more effective.

Neurosurgeons at a few teaching hospitals are beginning to use MRI software developed by Tannenbaum and his colleagues that visually slices the brain into more than 120 pieces using “interventional magnetics.” Within seconds, the slices are reconstructed into a 3-D image that illustrates the exact location and parameters of a brain tumor. Other software developed by Tannenbaum virtually flattens the brain onto a sphere, allowing visual access to the brain’s deep indentations.

Tannenbaum’s new system of virtual colonoscopy could be a major breakthrough in circumventing real colonoscopy—“one of the most popular procedures on the face of the planet,” he says. He believes this system is an improvement over another virtual colonoscopy system currently being tested at centers nationwide, including Emory, in which the radiologist visually scans a series of CT images, searching for the presence and location of polyps. The drawback, says Tannenbaum, is that radiologists must still do the searching themselves.

“Imagine if you could image the colon, reconstruct it virtually, then use that image to locate polyps,” says Tannenbaum. Imagine no more. Tannenbaum’s software cuts the colon open virtually, rolls it out like a ceremonial red carpet, then flattens it into a colorful, cartoon-like image before the eyes of a radiologist. The computer scans the virtual colon and highlights suspected polyps in green, allowing the radiologist to correlate the image with the original CT data and confirm the need—or not—for a real colonoscopy.

Tannenbaum is working with Emory radiologist William Torres to test the software system with patients at Emory Hospital, comparing it with traditional and virtual colonoscopy. Tannenbaum also is collaborating with Emory cardiopulmonary surgeon James Gruden on a similar imaging system that detects lung nodules and calcium deposits in arteries surrounding the heart.

“Our goal is to make the BME imaging group one of the best medical imaging groups in the world,” says Tannenbaum.
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Rigging repairs with proteins

Like Tannenbaum, cardiologist Zorina Galis segued early training in physical science to applications in medicine. She says part of her transformation to vascular biologist was her realization that years spent learning quantum mechanics and electrodynamics equations could lead to creative solutions to biological problems.

Galis studies the mechanisms of matrix metalloproteinases (MMPs)—enzymes that help cells “remodel” tissue by reshaping their surrounding “scaffolding,” or infrastructural matrix. As one of the world’s experts on MMPs, Galis has found that their effects can be either positive or negative. In cancer, tumors use MMPs to drill holes through the matrix and invade surrounding tissue. This knowledge led Galis to study atherosclerosis, in which plaque grows in blood vessels, causing inflammatory cells to migrate in and proliferate. She discovered that as plaques build up, cells use MMPs to reshape vascular walls in an effort to repair them.

Although vessel repair starts with the best of intentions, says Galis, there is no cellular switch to turn it off. When MMPs break down the scaffold to allow arteries to enlarge, they improve blood flow but at the same time weaken the plaques, causing them to rupture and block the vessel. She is studying ways to inhibit the harmful actions of some MMPs without stopping the beneficial effects of others. She consults with several companies studying MMP inhibitors to limit restenosis following angioplasty and to stabilize plaques in patients with atherosclerosis. “We have finally reached the point where we understand what drives plaque toward either vulnerability or stability, and the question now is how to stabilize it. This is a major topic now at every cardiology meeting,” Galis says. (BACK TO TOP)

Grafts of Gortex

Steve Hanson, another biomedical engineer concerned with the viability of blood vessels, is well known for his innovative approaches to improving artificial vessels and developing drugs to prevent and treat thrombosis.

Hanson’s current research is directed toward patients who need frequent kidney dialysis. For these patients, access to blood vessels in the arms or above the knee is an ongoing problem, often necessitating use of artificial substitutes commonly made from the Teflon-like material Gortex. The typical dialysis access graft in a patient’s arm lasts only 18 months and in a leg for several years. Often the grafts cause blood clots or other problems requiring surgery.

Hanson has patented a method of preserving the life of these artificial grafts by delivering drugs directly into the artificial vessels and into the often troublesome cut edges of the native connecting vessels. The engineered prosthetic vessels have worked well in primate studies, and Hanson has licensed the technology to Durect Corporation. He continues to work with a large group of colleagues within GTEC (the Georgia Tech/Emory Center for the Engineering of Living Tissues) to develop tissue-engineered substitute blood vessels designed from natural materials that could be used for bypass surgery or dialysis. (BACK TO TOP)

Miniscule pieces of matter

Cancer is another area rich in opportunities for the blended skills and perspectives shared by faculty in biomedical engineering. BME faculty member Gang Bao is using principles of physics and energy transfer to develop microscopic probes he hopes will detect pancreatic cancer. He believes his probe, also called a “molecular beacon,” might detect a specific mutation in a gene that is present in 80% to 100% of pancreatic tumors.

Dr. Bao’s research is part of the new science of “nanotechnology”—working with miniscule pieces of matter. The molecular beacon he uses is made up of a short sequence of single-stranded DNA code synthesized to match a genetic region where a mutation is known to occur. The beacon uses a technology called fluorescence resonance energy transfer. When the beacon finds its target—the mutated gene—the fluorescence is revealed.

Working with Winship Cancer Institute scientist Lily Yang and Emory surgeon Charles Staley, Bao hopes his technology can eventually be used to detect a range of tumor markers, including survivin, a gene expressed in most cancers.

The BME department recently recruited another nanotechnology expert, Shuming Nie, thanks to support from the Georgia Cancer Coalition. Nie is a world leader in detecting single molecules in biologic systems, and his work focuses on developing ultrasensitive tests for detection of cancer at an early stage. (BACK TO TOP)

A lot of work to do

“Our department has grown rapidly in a short time, and this is only the beginning,” says Don Giddens. “We’ve got a new building going up at Tech and space being renovated at Emory. And BME will more than double its current faculty, from 12 to 27, by 2005.

“We’ve got a lot of faith and resources vested in us, and all for good reason. Our job now is to to realize our potential through new discoveries that make a difference in people’s lives—and to train the next generation of people who will do likewise, and more so.”

Holly Korschun is director of science communications in the office of Health Sciences Communications.

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