Science in the Triangle

The idea came to Jeffrey Macdonald on frequent 3½-hour drives to Beaufort, where the associate biomedical engineering professor is scientific co-director at the Martin Ryan Institute for marine science.

On his way to the coast, Macdonald (photo on right) passed dozens of hog farms. North Carolina is the second largest U.S. hog producer behind Iowa. More than 10 million hogs live in the state, the vast majority of them near the coast.

The farms usually have open-air lagoons to collect and store the oodles of manure the hogs produce. Strict regulations limit their number and size, but the lagoons still pose serious health and environmental risks. They also lower property values.

On his drives, thoughts of hog manure were swirling in Macdonald’s head. “That’s considered an environmental contaminant,” he remembered thinking. “We should look at it as an energy source.”

Hog farmers already do. Some collect the methane that rises from the lagoons, capture it and burn it to generate electricity for the hog barns. Others burn dried hog manure for the same purpose. But Macdonald had an even better idea.

It’s not unusual for a university professor like Macdonald, who has students at N.C. State University and the University of North Carolina at Chapel Hill, is more than a teacher. Professors can also be inventors and entrepreneurs. Thousands of jobs in the RTP area exist, because university professors had ideas and formed companies to bring the ideas to market.

Biomedical engineering research lends itself to product development and spinning out startups is an integral component of the joint graduate program that NCSU and UNC-CH started in 2003.

Macdonald is one of four faculty members in the program who are working on ideas that have the potential to become businesses.

Mark Tommerdahl and Robert Dennis have come up with a sensory testing machine that can guide treatment of chronic pain, diagnose autism in people who otherwise function quite well and aid rehabilitation after a stroke. Glenn Walker is collaborating with a cardiologist at WakeMed to develop a catheter that can change in stiffness. And Macdonald is working on a bioreactor that turns hog manure into methane and then stows away in a closet.

Good vibrations

Cortical Metrics is “a garage business,” Tommerdahl said. “It’s me and Bob.”

The garage is a machine shop off the UNC-CH campus, where Dennis builds a sensory testing device (photo on right) that weighs a few pounds and fits into a backpack. The device generates gentle vibrations and taps certain spots on the fingers. Number and sequence of the taps follow protocols written by Tommerdahl, who is director of the UNC-CH Laboratory for Neurosensory Diagnostics.

The sense of touch in the fingers is so fine, the device provides information about what goes on in parts of the brain. The information is not only more detailed than medical images but also less expensive to obtain, Tommerdahl said. “[The test is] a cross between a blood pressure cuff and an eye exam. It gives you insight into how healthy the brain is. If certain metrics are off, you should have it looked at.”

A test takes about 20 minutes and the person tested must answer questions related to the taps. The answers provide researchers clues how well neighboring regions in a person’s cerebral cortex, the outer layer of the brain, are connected and able to communicate.

Since Cortical Metrics was founded in 2007, the company has sold devices to researchers in Boston, Toronto and New York City. The devices are used for a wide variety of research, from carpal tunnel syndrome to traumatic brain injuries.

But until they get a flurry of device orders, Tommerdahl and Dennis have no plans to expand the company or hire employees.

A catheter with character

Placing a stent to keep an artery in the brain, neck or heart from clogging takes about an hour in the operating room.

An interventional cardiologist mounts the tiny wire-mesh scaffold on the tip of a catheter and slips both through a small incision into a large blood vessel in the leg. The catheter pushes along in the blood vessel, but soon the doctor must switch catheters.

Blood vessels are like windy mountainroads, said Walker (photo on left). To get the stent around the turns, multiple catheters of different stiffness are required, which the doctor has to insert and pull out carefully to avoid damaging the blood vessel.

Walker, whose expertise is in microfabricated instrumentation, figured that a catheter with adjustable stiffness could cut the time it takes to place a stent to 15 minutes and reduce the cost of the procedure.

“We want to make it more of a one-shot deal,” he said.

That’s what he and Dr. Ravish Fachar, an interventional cardiologist at WakeMed in Raleigh, have been working on since they met during a lunch a few years ago.

The Coulter Foundation in Miami has been supporting their collaboration with nearly $500,000 over four years. Walker plans to build the first prototype next year. The tube would be made of a polymer, or plastic, that changes stiffness when an electrical current is applied with the help of a switch.

“We will commercialize,” he said, but it isn’t clear yet whether he and Fachar will sell the rights to their invention to a large company like Boston Scientific or Johnson & Johnson, or whether they will retain the rights and use a company Fachar has already founded.

Manur to methane

The model for Macdonald’s hog manure digesting bioreactor is the water cleaning mechanism in an aquarium.

A tube within a tube sucks the manure up and mixes it with different kinds of bacteria. The first batch of bugs breaks down the cellulose, fats and proteins, which a second batch then digests into amino acids, glucose and fatty acids. A third batch then turns the work product of the second batch into methane.

Macdonald wants to use bacteria that need no oxygen. Also known as anaerobic bacteria, these bugs live in some of the most inhospitable places, including deep below the ocean floor. They can also flourish in the human digestive tract and cause diseases such as appendicitis.

The bioreactor will be built “green,” which means that harmful gases and chemicals will be scrubbed out. Macdonald even plans to extract the cellulose so it can be diverted to ethanol production.

The “green” methane would then be burned to generate electricity.

“This technology would completely eliminate the lagoons,” Macdonald said.

In May, he founded a company called BioRxn to develop and commercialize the bioreactor. He built a prototype (photo on right).

But grant funding for the project has so far been elusive, so plans to hire two part-time technicians and a full-time director of research are on hold for now.

No reason to give up on the idea, though. There is always another round of funding coming up. Macdonald said he plans to apply again.