Magnetic pills deliver insulin to refill implanted reservoir

It is now more than 40 years since the first diabetic received an implantable insulin pump. Yet, the concept never took off, with Medtronic pulling the plug on R&D back in 2007. Now, a group of Italian researchers is trying to revitalize the approach with an implant refilled using magnetic capsules.

Infusing insulin into the peritoneal cavity could be more effective than subcutaneous administration. Recipients of the implants that were in development at Medtronic needed to visit a healthcare provider four times a year to get their devices refilled through syringes. Writing in Science Robotics, researchers have proposed an alternative way of getting insulin into pumps.

The system consists of an implantable reservoir that infuses insulin into the body cavity and is refilled using magnetic pills. In patients with the implant, insulin-loaded pills travel through the digestive system until they reach the small intestine. Then, the implant magnetically attracts the pill and forms a hole in its side to enable insulin to enter the reservoir.

In theory, the system would enable patients to manage their diabetes without the external devices or the refill tubes associated with existing insulin pumps. The wirelessly powered system controlled the blood glucose levels of three diabetic pigs in the study.

However, there are problems to solve before the device can advance toward human testing. Arianna Menciassi, Ph.D., an author of the paper, told IEEE Spectrum fluids entered the system when tested in the pigs. The devices appeared watertight in earlier testing but let fluids in in vivo, potentially when the implant punches a hole in the pill to access the insulin.