Swiss researchers develop bendable implant to tap into the spinal cord

The implant made of silicone and gold wires--Courtesy of École Polytechnique Fédérale de Lausanne

Swiss researchers have come up with a soft and flexible implant that has the same ability to bend and stretch as the membrane that wraps around the human brain and spinal cord, and could lead to helping people with paraplegia to walk again.

In previous work at the École Polytechnique Fédérale in Lausanne, Switzerland, scientists that included Gregoire Courtine and Stéphanie Lacour were able to come up with implanted devices that allowed mice with spinal injuries to walk again by sending patterns of electrical shock to their spinal cords, MIT Technology Review reported. However, the nervous systems of those mice ended up becoming damaged due to the rigid wiring of the implants.

Even if a device is very thin, stiff implants don't stretch like the spinal cord and eventually cause compression and tissue damage.

To overcome the damage, researchers developed what they dubbed "e-dura," which is made from soft silicone, gold wires that stretch and rubbery electrodes flecked with platinum. It mimics a property of human tissue called viscoelasticity, which falls between being like rubber and a very thick fluid. The device also contains a micro channel that allows for the delivery of drugs.

In writing for the journal Science, the researchers said they were able to wrap the device around the spinal cord of mice and send electrical signals to make their hind legs move. Additionally, drugs were pumped into the mice to enhance the process. Over a two-month period, the researchers reported the mice showed few signs of tissue damage compared to conventional electrodes, which tend to cause immune reactions.

"If you want a therapy for patients, you want to ensure it can last in the body," Lacour told MIT. "If we can match the properties of the neural tissue we should have a better interface."

Last year, a study published in Brain said a combination of physical therapy and treatment with Medtronic's ($MDT) spinal-cord-stimulating devices helped three men with paraplegia move their extremities and briefly stand up on their own. The combined therapies helped all three patients wiggle their toes, twist their ankles and flex their leg muscles, suggesting that, even when patients have lost the ability to move their lower bodies, the brain can still send signals to the spinal cord.

- check out the MIT article