Army scientists use fluorescent gels to study blast pressure on the brain
By David McNally, U.S. Army Research Laboratory Public Affairs
ABERDEEN PROVING GROUND, Md. — Army researchers are studying the physiological effects of blast pressure on the brain to discover technology solutions to protect Soldiers.
Scientists at the U.S. Army Research Laboratory, in partnership with the DOD Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Materiel Command, are developing nanomaterials to help understand the mechanism of brain injuries when Soldiers are exposed to blast conditions.
They have developed a gel substance with fluorescent properties that mimics the texture and mass of the human brain. Their goal is to show the scale of damage to the brain under the pressure conditions that Soldiers encounter in combat or training.
“We develop materials solutions that enable us to understand the mechanisms of damage at the cellular level,” said Dr. Shashi P. Karna, ARL nanofunctional materials senior research scientist. “What are the mechanisms by which the blast pressure waves travel to the brain?”
The laboratory is also creating materials that will enable the researchers to see details that have never been recorded. Using nanotechnology, scientists will see what happens to the brain during an explosion — at the cellular level.
“We have nanomaterials that are highly robust so that in real time, when the blast occurs, it will be possible to image the effects like an MRI, but with fluorescence,” Karna said. “Colors will show the motion of the cells.”
Researcher Nile Bunce said she and fellow researcher Rebecca Jimenez found that infusing the gel samples with fluorescent properties presented a complex technical challenge.
“It was more a trial and error,” Bunce said. “We got a nice dispersion of sample into our gels, and that’s what we’ve been going with so far.”
“Since our nanoclusters are pressure sensitive, when we apply pressure the fluorescence intensity will either increase or decrease depending on an increase or decrease in pressure,” Jimenez said.
Jimenez said they use ultraviolet light to illuminate the fluorescent materials.
“Depending on the type of metal that we use and the concentration, it can fluoresce anywhere on the visible wavelength spectrum,” she said. “It can be from blue all the way to red.”
To derive useful information about the effects of blast pressure on the brain from these colors, the team plans to develop a pressure scale, Bunce said.
“We put the nanoclusters under different pressures,” she said. “Based on how it fluoresces, under each certain pressure, we’ll make a graph and, from that, we can correlate it to how it will fluoresce in a brain situation.”
Over the past two years, the laboratory has built a partnership with the Japanese Ministry of Defense, which is working on the same problem. On Dec. 19, 2016, Japanese medical researchers visited Maryland for an update.
“The Japanese are addressing this through a medical technique … to look at the oxygen level, for example, in the tissue,” Karna said. “They also look at the cortical depressant. When the blast waves hit the brain, there is fluctuation in the blood circulation level. So they look at these physiological systems to assess what is affected by the blast.”
Karna said the Japanese team plans to test the Army’s samples with a laser-induced shockwave and share the results of the experiment.
“This is extremely important for us,” Karna said of the ongoing research. “The Army Research Laboratory provides the technology that enables the Soldier to function on the battlefield. It provides the best lethality and the best protection.”
The U.S. Army Research Laboratory is part of the U.S. Army Research, Development and Engineering Command, which has the mission to provide innovative research, development and engineering to produce capabilities that provide decisive overmatch to the Army against the complexities of the current and future operating environments in support of the joint warfighter and the nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.