Neurostimulation is the focus of a research group led by Eric Glowacki at CEITEC BUT. Thanks to an ERC grant, the researchers in Brno are working on wireless stimulation of peripheral nerves. The results of their work appeared in an article in the prestigious Nature Biomedical Engineering journal. The article presents a unique implant to scientists around the world. This implant supplies the necessary energy to the body through the skin.

The general principle of neurostimulation methods is electrical and magnetic stimulation, which targets either the peripheral area or the central nervous system. One of the most common targets of electrical neurostimulation is the vagus nerve, which runs from the brain through the neck to the abdominal cavity. Its stimulation can help those who have suffered an injury or suffer from epilepsy, but various inflammatory autoimmune diseases are also respond to such stimulation. Therapeutic effects were thus demonstrated, for example, in patients with Crohn’s disease.

So far, the only help available were pacemaker-type implants, which, however, need to be recharged at regular intervals, which unfortunately requires further invasive surgery. Eric Glowacki’s team brings a new, non-invasive, and above all minimalist solution: “Our goal was to come up with a very small stimulator, so that its implementation would be more comfortable for patients. It should be placed on the neck, with the device being recharged by light. No one has ever thought about shining through the skin, but the tissue is transparent, so high energy densities can safely penetrate the skin to a reasonable depth,” explains Glowacki. In practice, the patient would be able to “dose” the amount of energy needed using a laser pointer. In the case of Crohn’s disease or certain forms of epilepsy, he said, just a few minutes a day would suffice.

Glowacki’s international team has already conducted a pilot surgery at the Columbia University in New York. In less than ten minutes, the scientists wrapped an ultra-thin plastic tape around the sciatic nerve of a lab rat. This is a very well-known animal model, because the sciatic nerve is responsible for the movement of the leg. This allows us to easily see if neurostimulation is successful. Unfortunately, the observations lasted only 100 days, and the experiment was forced to stop due to complications associated with the coronavirus pandemic.

Nevertheless, the results were stunning. “After removing the tape, which was created by the scientists in Brno, the nerve was perfectly fine, the rat’s body did not perceive it as something unwanted; in general, what is small is better tolerated by the body,” said the team leader. He also specified that the material is biocompatible, as it is an inert plastic used for implants. The photosensitive elements are commercial pigments that are used in the cosmetic industry.

Glowacki’s team began researching this material during their time in Sweden. However, due to better equipment and new opportunities, they decided to move to CEITEC BUT in Brno at the end of last year, where Glowacki would like to introduce similar animal experiments in natural conditions.

Members of the research team are confident that within a few years they will be able to deliver a device suitable for use in humans. The results published in Nature Biomedical Engineering clearly demonstrate that the method is safe and functional. It is the efficiency and safety of this implantable stimulator that is the essence of all efforts for Brno scientists. Therefore, there are many more experiments to be carried out before it is ready to be adapted for therapeutic applications in human patients.

Eric Glowacki himself believes that the results of their work may inspire other scientists, especially those working on externally powered sensing and stimulation technologies such as micropumps. LED-based lighting is extremely cheap and it is a commercial light source that is available anywhere. According to Glowacki, light is the ideal solution.

This holder of the prestigious ERC grant has a clear goal in mind for the future. “I would like to achieve the possibility of clinical application of our discovery, helping people is the biggest motivation for me and my team. We are really close. I can feel it. We have a clear vision of how to move forward and CEITEC BUT has the right conditions for that.”

Who is Eric Glowacki?