Skin implant clears blood sugar in diabetic mice without drugs

A wireless, drug-free implant normalized blood glucose in obese diabetic mice, but it is far from human use and faces open safety and scaling questions.

A study published October 22 in Science describes a wireless implant, about 3 centimeters long, that sits under the skin and removes excess glucose from blood. It uses no added drugs, genes or living cells. In mice with both type 2 diabetes and obesity, high blood sugar returned to normal within 60 to 90 minutes of switching it on. After six weeks, treated mice lost up to 10 percent of their body weight and had lower blood triglycerides.

The device relies on a catalyst of gold flakes and platinum particles on spongelike graphite. When powered by electricity, it converts glucose to gluconate, which the kidneys can excrete in urine. A wearable glucose monitor sends readings through a smartphone, which turns the implant on at high glucose and off once levels return to a safer range. That automated loop ran for two weeks in eight mice. The catalyst still worked after up to three months under mouse skin, though total device lifespan was not established.

Why it matters: diabetes affects about 830 million people worldwide, and treatment usually means lifelong medication. A device that works on glucose directly, without a drug, could in principle lower that ongoing cost and dependence. That is a long way off, and it is our read rather than something the study shows.

The caveats are large. Results are in mice only. In a lab test, a larger device cleared nearly all glucose from about 5 liters of solution, roughly adult blood volume, but not a full day's intake. Outside endocrinologist David Klonoff estimates humans eat about 250 g of carbohydrate daily versus about 2 g for mice, so people may need a much larger device or several. He also flags risks to rule out first: gluconate buildup upsetting acid-base balance, and loss of electrolytes such as sodium and potassium. How much gluconate kidneys can clear is unknown. The fat-burning explanation for weight loss is the team's suspicion, not established. Martin Fussenegger's group at ETH Zurich plans tests in pigs and sheep before considering human trials.

Source: Science News