Soft spinal implants show promise as long-term solution to paralysis

Date: Jan-12-2015 In theory it should be possible to implant devices that send the right mix of electrical pulses and chemicals down the spinal cord to restore movement after paralysis. But the practical challenge is finding not only something that functions, but also that matches the soft tissue of the spinal cord.

The e-Dura implant is made of a material that matches the soft tissue of the spinal cord.
Image credit: EPFL/Alain Herzog

Spinal injury researchers have tested various types of implants but have reached a roadblock; while the devices perform to begin with, in the longer term the soft and stretchy tissue in the spinal cord rubs against the rigid material.

Over time, these traditional implants lead to inflammation, scar tissue build-up and immune rejection.

Now, in a new Science study, researchers from Switzerland and the US describe how they tested a small device made from a flexible material that matches the mechanical properties of living tissue and delivers the appropriate electrical impulses and chemicals. They also show how it restored movement in rats paralyzed by spinal cord injury.

After implanting it into rats, the researchers found the device caused no tissue damage and was not rejected, even after 2 months. Traditional implants - because they are more rigid - would have caused significant nerve tissue damage during this period of time.

The new implant matches the shape and mechanical properties of the dura mater

The device - called the e-Dura implant - comprises a transparent silicone substrate patterned with microfluidic channels that deliver drugs, and soft electrodes made of platinum and silicone with stretchable gold interconnects that transmit and transfer electrical signals.

The e-Dura implant material matches the shape and mechanical properties of the dura mater - the protective membrane of the brain and spinal cord.

Study co-author and expert in neuroprosthetics Stéphanie Lacour, a professor at the École polytechnique fédérale de Lausanne (EPFL) in Switzerland, says:

"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."

A feature of the implant is that it can monitor electrical signals from the brain in real time. When the researchers did this, they were able to see precisely what the rats' next intended movements were before they actually performed them.

Lacour talks more about the e-Dura device in the video below:

Expertise from several fields came together to make the device

The material is the result of expertise coming together from different fields - including materials science, electronics, neuroscience, medicine and computer programming.

While currently still working with rats, the researchers are planning to move into clinical trials in humans. They foresee a promising future for the e-Dura implant in the treatment of a wide range of diseases, including epilepsy, Parkinson's disease and pain management.

In October 2014, Medical News Today reported how a paralyzed man from Poland was able to walk again after nose cells repaired his spinal cord. Surgeons carried out a procedure that made a bridge over the injury site so nerve cells - encouraged by a special type of nose cell called an olfactory ensheathing cell (OEC) - could regrow across the scar tissue.

Written by Catharine Paddock PhD

Not to be reproduced without permission.

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.