Researchers from EPFL have restored the walking ability of paralyzed rats by implanting soft and flexible neural implants directly onto their spinal cord. The incredible new technique, which doesn't cause inflammation or damage, uses both chemical and electrical stimulation.

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It's hoped that this technology, called e-Dura, could be eventually be extended to humans, but the technique would require a suite of multifunctional implants installed over the course of long periods.

The device, which was developed by EPFL researchers Stéphanie Lacour and Grégoire Courtine, is designed specifically for implantation on the surface of the brain or spinal cord, and without causing any damage to tissues.

An EPFL release explains:

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. More rigid traditional implants would have caused significant nerve tissue damage during this period of time.

The researchers tested the device prototype by applying their rehabilitation protocol — which combines electrical and chemical stimulation – to paralyzed 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 paralyzed following spinal cord injury," explains Lacour, co-author of the paper, and holder of EPFL's Bertarelli Chair in Neuroprosthetic Technology.

The researchers add that it could also be used to treat epilepsy, Parkinson's disease and pain management.

The rubbery implant includes electronic components that stimulate the spinal cord in the damaged areas. The silicon substrate can be pulled and stretched, while still ensuring optimal levels of electrical conductivity. A fluidic microchannel allows for the delivery of pharmacological substances, namely neurotransmitters that "reanimate" the nerve cells beneath the injured tissue. Fascinatingly, the system can monitor electrical impulses from the brain, allowing the scientists to see the rats' motor intentions before it's translated into movement.

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In terms of next steps, the researchers are hoping to move to clinical trials in humans.

Read more here and here; and check out the entire study at Science: "Electronic dura mater for long-term multimodal neural interfaces".

Images: EPFL.

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