A wireless implant that clears excess sugar from the blood could someday offer a drug-free way to treat type 2 diabetes and obesity.

In mice with both conditions, the under-the-skin device brought high blood sugar back to normal within 60 to 90 minutes of being switched on, researchers report October 22 in Science . After six weeks, the treated mice lost up to 10 percent of their body weight and had lower triglycerides, a type of fat in the blood.

Diabetes affects about 830 million people worldwide. Conventional type 2 diabetes treatments like insulin and GLP-1 drugs require careful dosing. Even experimental diabetes-controlling implants still rely on the hormone insulin, which clears sugar from the bloodstream but doesn’t rid the body of it, says Martin Fussenegger, a bioengineer at ETH Zurich. The new implant instead removes glucose from the body without added drugs, genes or living cells.

The 3-centimeter-long device contains a catalyst made of gold flakes and platinum particles on spongelike graphite.…