Purdue team takes aneurysm research to nation's capital

<p>ERIC WEDDLE</p>Journal & Courier Published:

WEST LAFAYETTE, Ind. (AP) -- Brain aneurysms caused by bomb blasts and other severe trauma could one day be treated by biomedical technology developed at Purdue University.

A team of faculty and students is creating tiny irradiated stents intended to speed up cell formation inside blood vessels to close off the sac-like bulges in the vessels caused by weakening of artery walls.

Jean Paul Allain, an associate professor of nuclear engineering leading the research, recently traveled to Washington, D.C., to brief Congress on the medical technology for the first Brain Mapping Day. The event was for lawmakers to hear how nanotechnology can be used to treat brain injuries and disease.

Allain's work is funded with a three-year, $1.5 million grant from the U.S. Army.

"The reason I got into this was because it would have an impact on people. When you hear about nuclear engineers, it's about nuclear power plants, and the overall impact you bring to people is clean energy," Allain said.

"But nuclear engineering is a very broad field, it's very multidisciplinary and most people don't understand that.

"I felt this was a great way to demonstrate that nuclear engineering can have great impact somewhere else, in biomedical engineering. But will it have a big impact? That we don't know yet."

Allain became interested about five years ago in how irradiation can induce microscopic formations known as nanostructures and how these nanostructures could effectively influence biological behavior at the cellular level. But the grant was awarded just a year and half ago to start work on the problem.

To create this "bioactive" coating for the stents and understand how they would interact with the human body, a multidisciplinary team of faculty and students was assembled involving the West Lafayette campus, Walter Reed National Military Medical Center and the country of Colombia.

Ravindra Kempaiah, a materials engineering doctoral student, said the purpose of the work is to find a way to close up brain aneurysms quickly without invasive and potentially complicated brain surgery. Such surgery can involve clipping aneurysms shut or implanting a metallic coil into the sac via a catheter.

Soldiers in combat can suffer brain aneurysms when they are struck by blasts from improvised explosive devices.

"It is completely new," Kempaiah said. "It is like solving a biological problem from an engineer's point of view. It is like a synergy of engineering and biosciences."

Lisa Reece, a lab director at the Birck Nanotechnology Center and co-leader on the project, said cells that repair blood vessels are attracted by the texture and chemistry of stent materials.

"All cells in our body have a specific function. We want to work with stem cells because they can be easily programmed into anything, and hopefully they will be programmed into something to close the neck (of the vessel bulge) off," Reece said. "With the radiated topography, the cells really like something that is rough. They don't like something smooth. Hopefully that will help recruit more cells to that area to close off the neck.

"There is a lot of biochemistry going on. The cells have to signal each other so they can come on over. The physical and biochemistry have to mingle very well."

Allain explained that the tiny stents are created with bioactive coating. This will attract stem cells to repair blood vessels damaged in a blast or other trauma.

The stent coatings are modified with beams of charged particles, called ions, to modify the stent coatings with a magnetic material. The ion beams also are used to create lifelike or surface textures, or "biomimetics," which are to promote cellular proliferation and repair damaged vessels, Allain said.

Allian expects to have a stent prototype finished by the end of summer. It will then be tested using blood from pigs in collaboration with the Walter Reed National Military Medical Center. A second phase of study would begin after.

The Purdue team is working with Col. Rocco Armonda, Dr. Teodoro Tigno and other neurosurgeons at Walter Reed National Military Medical Center in Bethesda, Md. Collaborations also are planned with research scientists from two universities in Colombia.

"It is a pretty complicated problem," Allain said. "This is not something you can solve in three years. It might take 10. But you have to start somewhere."

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