A bio-hybrid implant makes paralyzed limbs move again

People with prostheses or paralyzed limbs may soon be able to move their arms or legs independently again, thanks to a new neural implant developed by scientists at Cambridge. It works well on mice.

The bio-hybrid device improves communication between the brain and a prosthetic or paralyzed limb. Using flexible electronics and a layer of human stem cells — reprogrammable source cells, which in this case act as muscle cells — nerves in the shoulders or hips are integrated into a prosthetic arm or leg without forming scar tissue at the site of attachment. This is crucial.

Stem cells prevent scar tissue
Previous attempts to use nerve implants to restore limb function failed, among other things, because scars formed around the electrodes within a few days. As a result, the nerve signal deteriorates and is eventually lost completely. The Team Solution for the prevention of tissue scarring is an innovative solution. By sticking a layer of muscle cells between the electrodes and living tissue, the lab rats kept the signals on throughout the experiment, for 28 days. This is unique to this relatively new branch of science.

Meets vital cellular therapyelectronics
According to neuroscientists, the key to successful nerve regeneration lies in the combination of cell therapy and bioelectronics. They created a single device that overcomes the shortcomings of both disciplines. As a result, the function and sensitivity of the implant are greatly improved. A number of follow-up studies are still needed before the device can be used in humans, but the team is convinced it’s on the right track.

Nerves help
It is still virtually impossible to repair a broken or severed nerve. Nerves cannot or hardly regenerate. So the broken nerve pathways need a helping hand. “If someone loses an arm or a leg, the nervous system will continue to send signals. The big challenge in integrating prostheses and restoring function in the arms or legs is to get the information from the nerve to the extremities until function in the arms is restored,” says University of Cambridge researcher Damiano Barone. and legs.

First time
This is it First time That stem cells are used in an organism in this way. “These cells give us a lot of room to move and control. We can tell them how to act and check in the meantime if everything is going right. Because we put stem cells between the electronics and the body, the body doesn’t recognize the electrodes. It only observes muscle cells,” Baron explains. , and therefore does not produce scar tissue.In this way, it was possible to send nerve impulses from the motor part of the rat’s brain to the prosthetic legs.Four weeks later, the neural bridge was still working perfectly.

Brain machine interfaces
“This interface could revolutionize the way we interact with technology,” said researcher Amy Rochford. “By connecting living human cells with bioelectronic materials, we have developed a system that can communicate with the brain in a more natural and intuitive way. This offers new possibilities for prosthetics, but also for brain-machine interfaces and even improving cognitive skills is on the agenda.”

“It was uncertain whether our research would bear fruit,” says Professor George Maliaras. “This is one of those projects where you have no idea if it’s going to take two years or 10 years to see results, but it went very well. We’re so glad it worked.”