MIT has created “fitness bracelets” for neurons – they envelop cells and help them be healthy

Science has learned a lot about the functioning of the nervous tissues of the brain, but this does not make the mysteries any less. In fact, scientists do not have enough subtle instruments to monitor brain activity and processes at the subcellular level without harm to humans or animals. Researchers from the Massachusetts Institute of Technology tried to bridge this gap and introduced a platform they called “wearable devices for cells.”

Image source: Pablo Penso, Marta Airaghi

With the advent of fitness bracelets, smart watches and similar gadgets, the lives of many people have changed for the better. There is an opportunity to constantly monitor your health, sleep quality and get an incentive to be physically active. Scientists have come up with something similar for nervous tissue cells. Tiny micron-scale film devices are inserted into the brain and envelop the nerve endings of neurons – axons and dendrites.

Image source: Nature 2024

Envelopment – folding into a tube around these cellular structures of neurons occurs when the films are activated by light, which seems preferable to surgical implantation. In their work, the scientists illuminated the material with green light in the range of 545–555 nm. Enveloping along or across and up to a given diameter is carried out by changing the intensity and polarization. In other words, it is a completely managed process. The issue of penetration deep into the brain remains open, but can certainly be solved if we select the range of radiation that penetrates living tissue.

Azobenzene was tested as a material for artificial nerve sheaths. It has shown complete biocompatibility (in experiments on mice) and can be used to work with nervous tissue of the human brain. Since azobenzene is an insulator, its coating of neural processes can increase their conductivity, which, for example, can help in the treatment of diseases such as atherosclerosis, when living tissue cannot independently restore electrical insulation.

The researchers have also developed a process for mass-producing azobenzene micron films using relatively simple methods, without resorting to cleanrooms known in semiconductor manufacturing. Azobenzene is applied to a water-soluble base and formed with a micro-stamp, after which the base dissolves. This promises to make the technology widely available.

In the future, it will be possible to create flexible nanoelectronic circuits on azobenzene film to control or fix the activity of neural processes. Then they will become real fitness bracelets for cells. We will be able to monitor subcellular activity and better understand how the brain works and treat diseases that affect it.