By Dana Yamashita

The central nervous system controls physical responses in the body, both conscious movement and automatic responses such as breathing, via neurons that relay signals to the body. For the nearly 20,000 people in the United States who are left paralyzed due to car crashes, falls, gunshot wounds, or other types of trauma each year, the ability to have brain-controlled prosthetic limbs or muscle stimulation devices would significantly increase quality of life.

When microelectrodes are implanted in the brain, an inflammatory response often occurs, causing scarring near the implant and a loss of neurons. Eventually, this diminishes the current of information being fed from the brain to the prosthetic device.

With the support of a four-year $1.2 million grant from the Department of Veterans Affairs, an interdisciplinary team of engineers from Rensselaer Polytechnic Institute seeks to create a polymer coating that could potentially reduce the body’s inflammatory response following the implantation of these electrodes.

“This is for veterans who have some sort of paralysis,” said Ryan Gilbert, professor of biomedical engineering. “The electrode would allow for the patient to communicate with external devices to power a robotic arm or to communicate with some sort of server to help the veteran live a better life.”

Gilbert and Edmund Palermo, assistant professor of materials science and engineering, hope to develop a polymer coating out of curcumin, a chemical compound found in turmeric, which has both anti-inflammatory and antioxidant properties.

“The chemistry and the coating processing require careful optimization,” said Palermo.

Once the coating is developed, the team will also need to design a technology for coating the electrode so that it will be able to withstand implementation. They want the final polymer to slowly release the curcumin so it will neutralize inflammation at the implementation site and then degrade away, so as to not interfere with the electrode’s electrical conductivity.

“It needs to be a degradable coating that protects the implant on the way in, tamps down the injury, and then allows the neurons to establish a connection,” Palermo said.