Wireless Implantable LEDs Could Block Pain SignalsIn recent months, scientists have successfully developed flexible, implantable devices that can activate and, in theory, block pain signals in the body and spinal cord of mice before these signals reach the brain.
The implants one day may be used in different parts of the human body to fight pain that doesn’t respond to other therapies, said the researchers from Washington University’s School of Medicine in St. Louis and the University of Illinois at Urbana-Champaign.
Dubbed as a "switch" for pain, the device uses micro-LED lights that activate nerves to block pain signals in the spinal cord and other parts of the body before reaching the brain for processing and interpretation. Because the devices are soft and malleable, they can be implanted into various parts of the body, including moving parts, Robert Gereau IV explained, a Professor of Anesthesiology and director of the Washington University Pain Center. The devices previously developed by the scientists had to be attached to bone.
“When we’re studying neurons in the spinal cord or in other areas outside of the central nervous system, we need malleable implants that don’t require anchoring,” said Gereau.
The device is held in place with sutures. Gereau said he hopes to use the implants to blunt pain signals in patients who have pain that cannot be managed with standard methods of therapy.
Gereau and his colleagues experimented with mice that were genetically engineered to have light-sensitive proteins on some of their nerve cells. To demonstrate that the implants could influence the pain pathway in nerve cells, they programmed pain response signals to respond to LED light. When the mice walked through a specific area in a maze, the implanted devices lit up and caused the mice to feel discomfort. Upon leaving that part of the maze, the devices turned off, and the discomfort dissipated. As a result, the animals quickly learned to avoid that part of the maze.
The experiment would have been very difficult with older ontogenetic devices, which are tethered to a power source and can inhibit the movement of the mice.
The new devices are small, flexible and can be held in place with sutures, so they have potential use in or around a variety of body parts, including the bladder, stomach, intestines, heart or other organs, according to co-principal investigator John A. Rogers, PhD, professor of materials science and engineering at the University of Illinois.
“They provide unique, biocompatible platforms for wireless delivery of light to virtually any targeted organ in the body,” he said.
Rogers and Gereau designed the implants with an eye for manufacturing processes that would allow for mass production so the devices could be available to other researchers. Gereau, Rogers and Michael R. Bruchas, PhD, associate professor of anesthesiology at Washington University, have recently launched a company called NeuroLux to help them reach their goal.