Shape-shifting nerve implants to revolutionize neurology

By Katie Robinson | Fact-checked by Barbara Bekiesz
Published May 29, 2024

Key Takeaways

  • Researchers have developed flexible implants that wrap around peripheral nerves and change shape through electrical activation, without causing nerve damage.

  • The implants could advance minimally invasive monitoring and treatment for many neurological conditions, such as pain and movement disorders.

  • The technology was validated in a non-clinical study, and human trials may start in the next few years.

University of Cambridge researchers have developed flexible implants that wrap around nerves and change shape through electrical activation, without causing nerve damage.[]

As reported in the journal Nature Materials, the researchers suggest the technology could advance minimally invasive monitoring and treatment for many neurological conditions.

“The ability to make an implant that can change shape through electrical activation opens up a range of future possibilities for highly targeted treatments,” said study lead George Malliaras, PhD, in a university press release.[] In the future, “we might be able to have implants that can move through the body, or even into the brain,” he said, adding that “it makes you dream how we could use technology to benefit patients in future.”

Current bioelectronic medicine technology

Electric implants that allow direct access to peripheral nerve fibers enable accurate and selective nerve modulation, stimulating or blocking signals in target nerves.

Such devices are used in bioelectronic medicine to treat chronic pain, metabolic diseases, and movement disorders, as in the restoration of movement in paralyzed limbs. The implants can also record nerve activities, helping to diagnose conditions and provide monitoring during surgical procedures.

However, complex surgeries are required to implant the devices and come with a risk for nerve injury. Dr. Malliaras explained that “nerves are small and highly delicate, so anytime you put something large, like an electrode, in contact with them, it represents a danger to the nerves.”

Co-author Damiano Barone, MD, PhD, explained that while implants that wrap around a nerve (nerve cuffs) present a lower risk of nerve damage than electrodes that penetrate nerves, they are “too bulky, stiff, and difficult to implant, requiring significant handling and potential trauma to the nerve.”

Pre-clinical study

The researchers developed flexible, ultra-thin, and low-voltage implants. The implants comprise two separate layers made from conducting polymers that swell or shrink when tiny amounts of electricity are applied. Tiny enough to be rolled up into a needle, the devices wrap around peripheral nerves when injected at the target nerve site, allowing nerve activity to be monitored or modified.  

The low voltage ensures safety for use inside the body, while the ability to change shape in both directions and undergo reprogramming means surgeons can adjust how tightly the device fits around a nerve.

This allows surgeons to achieve the “best results for recording and stimulating the nerve,” explained first author Chaoqun Dong, PhD.

The technology was validated in a pre-clinical study. When implanted in rats, the devices were successfully placed without the need for surgery. They formed an intimate self-wrap around the target nerve, which is required for reliable recording of the nerve activity.

The researchers reported on the implants’ resilience, stating that they can withstand hundreds of cycles of folding and unfolding inside the body—a feature that allows surgeons to adjust implant placement.

It also eliminates the one-time-use restraint with existing shape-changing nerve implants. Moreover, nerve injury could be avoided as the implants require only minimal clamping force and are easily removed.

Clinical implications

According to the researchers, indications for the implants include intraoperative nerve monitoring, such as during tumor extraction. The ability to reposition the devices during implantation could be of benefit in other clinical situations, such as vagus nerve stimulation.

After further testing in animal models, the researchers plan to start clinical trials within the next few years.

“Using this approach, we can reach nerves that are difficult to reach through open surgery, such as the nerves that control pain, vision or hearing, but without the need to implant anything inside the brain,” said Dr. Barone. The placement of these implants makes for “a much easier procedure for surgeons, and it’s less risky for patients.”

What this means for you

Current electric nerve implants used in bioelectronic medicine come with a risk of nerve damage. Researchers have developed flexible, ultra-thin implants that wrap around peripheral nerves and change shape through electrical activation, without causing nerve damage. Pre-clinical studies are continuing, and human trials are expected to follow within the next few years.

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