Swiss scientists at the Ecole Polytechnique Fédérale De Lausanne have developed a flexible, biocompatible implant that uses chemical and electrical stimulation to help paralyzed rats to walk again.
Researchers are working on developing multi-functional implants that could be placed on the human spinal cord for long periods of time without causing tissue damage. The e-Dura implant could be applied directly on the spinal cord without causing inflammation or damage. It also can be implanted on the surface of the brain. The e-Dura implant closely simulates the mechanical properties of living tissue and pharmacological components, and deliver electrical impulses.
The scientists say that the device has a much lower risk of damage or rejection and have certain advantages over so-called “surface implants.” Surface implants are rigid and cannot be applied long term to the spinal cord or brain beneath the nervous system’s protective sheath known as the “dura matter.” The implants rub against nerve tissues when they stretch or move, eventually causing rejection, inflammation, and scar tissue buildup. The stretchy and flexible implant is placed under the dura matter and directly onto the spinal cord. The paralyzed rats were able to walk after undergoing a few weeks of training.
“Our e-Dura implant can remain for a long period of time on the spinal cord or the cortex, precisely because it has the same mechanical properties as the dura mater itself. This opens up new therapeutic possibilities for patients suffering from neurological trauma or disorders, particularly individuals who have become paralyzed following spinal cord injury,” explains Lacour, co-author of the paper, and the EPFL’s Bertarelli Chair in Neuroprosthetic Technology.
The implant contains electronic components that stimulate the spinal cord at the point of injury. The electrodes can be manipulated in any direction to optimal conductivity. A fluidic microchannel carries pharmacological substances that will reanimate the nerve cells under the injured tissue. Scientists can also use the system to monitor electrical brain impulses in real time. They could predict the animal’s motor intention before it moved.
“It’s the first neuronal surface implant designed from the start for long-term application. In order to build it, we had to combine expertise from a considerable number of areas,” explains Courtine, co-author and holder of EPFL’s IRP Chair in Spinal Cord Repair. “These include materials science, electronics, neuroscience, medicine, and algorithm programming.” Researchers are developing a prototype for testing in humans.