Electronic implant uses electricity to treat diabetes in mice

The development comes as type 2 diabetes, frequently associated with obesity and physical inactivity, affects a growing number of people worldwide. Insulin injections help lower blood sugar by allowing cells to absorb glucose, but they do not address the underlying excess energy, which can be stored as fat and lead to weight gain, a problem the new implant aims to solve.

The implant was developed by researchers led by Martin Fussenegger of ETH Zurich's Department of Biosystems Science and Engineering and is built around a catalyst made entirely from inorganic materials. A piece of graphite felt is coated with tiny gold clusters and even smaller platinum particles, creating a surface that converts glucose into gluconate. The gluconate can then be passed out of the body in urine, preventing that portion of glucose from being stored as fat.

The system receives wireless power at 13.56 MHz, a frequency allocated for industrial, scientific and medical use, and is controlled by an external device. A conventional glucose sensor, similar to those already worn by people with diabetes, measures glucose in tissue and communicates via Bluetooth with a smartphone or smartwatch. When glucose levels rise too high, the connected device activates the implant, which converts the excess glucose. Once levels return to the desired range, the implant shuts off automatically in what is known as closed-loop control, designed to prevent dangerously low blood sugar.

In laboratory tests, the catalyst successfully processed glucose from a 5-liter nutrient solution, about the volume of blood in an adult human. The researchers then implanted the system in diabetic mice. Over six weeks, the device precisely regulated the animals' blood sugar and led to weight loss. The implant continued functioning reliably and was well tolerated.

Fussenegger said the system operates at a very low voltage, and that experiments showed no evidence of tissue damage from electrical or thermal effects.

Fussenegger believes the approach could represent a fundamental change in diabetes management. “For decades, we have treated diabetes by telling the body how to manage glucose. We are now showing that we can take control of glucose directly, using electronics rather than drugs,” Fussenegger said. “And the catalyst only activates when glucose levels are too high.”

The approach also creates opportunities to connect medical treatments with digital technologies, including the Internet of Things. Wireless power transmission systems and external electronic controllers are already commercially established.

The team's next goal is to turn the experimental implant into a medical device suitable for further development and eventual clinical testing. Because the catalyst does not rely on cells or enzymes, the researchers believe some of the challenges of biological treatments, such as immune compatibility and stability, may be easier to overcome. Whether the technology will work safely and effectively in humans has yet to be determined.