Spinal implant could allow paralysed people to walk again

Scientists have used a new flexible implant to allow paralysed rats to walk again, paving the way for new therapies for people with spinal cord injury.
The e-Dura implant developed by Swiss Federal Institute of Technology Lausanne (EPFL) scientists can be applied directly to the spinal cord without causing damage and inflammation.
EPFL scientists have managed to get rats walking on their own again using a combination of electrical and chemical stimulation.
But applying this method to humans would require multi-functional implants that could be installed for long periods of time on the spinal cord without causing any tissue damage, researchers said.

The implant developed by the teams of professors Stephanie Lacour and Gregoire Courtine is designed specifically for implantation on the surface of the brain or spinal cord.
The small device closely imitates the mechanical properties of living tissue, and can simultaneously deliver electric impulses and pharmacological substances.

The risks of rejection and/or damage to the spinal cord have been drastically reduced, researchers said.
So-called "surface implants" have reached a roadblock; they cannot be applied long term to the spinal cord or brain, beneath the nervous system's protective envelope, otherwise known as the "dura mater," because when nerve tissues move or stretch, they rub against these rigid devices.

After a while, this repeated friction causes inflammation, scar tissue buildup, and rejection.
Flexible and stretchy, the implant developed at EPFL is placed beneath the dura mater, directly onto the spinal cord. Its elasticity and its potential for deformation are almost identical to the living tissue surrounding it.
This reduces friction and inflammation to a minimum. When implanted into rats, the e-Dura prototype caused neither damage nor rejection, even after two months.
The researchers tested the device prototype by applying their rehabilitation protocol - which combines electrical and chemical stimulation - to paralysed rats.
Not only did the implant prove its biocompatibility, but it also did its job perfectly, allowing the rats to regain the ability to walk on their own again after 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 paralysed following spinal cord injury," said Lacour, co-author of the paper.
The finding appears in the journal Science.