Building an artificial pancreas

U, Mayo Clinic working to develop a revolutionary treatment

Diabetes never takes a break.

For people living with type 1 diabetes, the task of monitoring blood glucose levels and administering insulin is always at the forefront of their minds. It’s something they must do multiple times a day, every day.

But University of Minnesota and Mayo Clinic scientists are working together to build an artificial pancreas that would eliminate this burden.

As part of this work, the University’s Steven Koester, Ph.D., an electrical engineer, is designing a more accurate and reliable continuous glucose sensor that would make the artificial pancreas a better treatment option.

Tackling the sensor problem

For the last five years, Mayo Clinic researchers, Yogish Kudva, M.B.B.S., and Ananda Basu, M.B.B.S., M.D., have been developing an artificial pancreas for treating type 1 diabetes.

Here’s how it works: The artificial pancreas consists of a continuous glucose sensor, insulin pump, and a computer algorithm that controls the insulin delivery—accessed by a laptop or hand-held device. The sensor and insulin pump are placed at two separate sites under the skin on the abdomen. The sensor records the glucose data, the computer algorithm calculates how much insulin a patient needs (and when), and the insulin pump then delivers insulin beneath the skin.

To date, teams engaged in artificial pancreas research have relied on commercial glucose sensors for this device, but those sensors have many limitations.

One major drawback is that the commercial sensor provides data about glucose levels in tissue, but not in blood. “If there is a delay in what happens in blood verses tissue, the data becomes less reliable,” says Kudva.

The sensor’s location on the body also must be changed every three to seven days—a nuisance that could inhibit use by patients. In addition, the commercial sensor is also about the size of two postage stamps. If it were even smaller, Kudva says, more people may be willing to wear it.

Other shortcomings: “The [sensor’s] lifetime is relatively short,” Koester says. “A new sensor is needed every three to seven days.” And the sensor’s wires stick out of the patient’s body.

Koester hopes his new sensor will provide better usability and data for the artificial pancreas. “The Achilles’ heel is the sensor—it could be done better,” he says.

The U’s new sensor

To improve upon the current technology, Koester is testing a material called graphene that would be placed under the skin. “It’s a two-dimensional piece of carbon that’s one atom thick,” he explains.

He also is working on attaching receptors to the graphene sensor so that it can detect glucose. The sensor then wirelessly sends the data to the device’s computer, which tells the insulin pump what to do.

The wireless graphene sensor is much smaller than the current commercial sensor—about the size of a grain of sea salt. Because of the small size and lack of wires, Koester says, it could be put in more inconspicuous places.

“It’s a new way of doing sensing,” he says. “You could get a better glucose reading.”

Gathering more accurate glucose data would help patients who are living with diabetes, Kudva says. “If we get a more reliable signal, then we can fine-tune the insulin better.”

Philanthropic support needed

This collaboration was made possible by a $500,000 grant from the Decade of Discovery—a statewide initiative of the Minnesota Partnership for Biotechnology and Medical Genomics, a collaboration of the University, Mayo Clinic, and the state of Minnesota. But that funding will soon run out.

Mayo Clinic will be conducting human testing of the artificial pancreas with the commercial sensor. But more funding is needed to further develop the University’s new graphene sensor before it can be tested in clinical trials.

Both Kudva and Koester agree that philanthropy could play a big role in advancing this work. “To make an impact quickly, it could be tremendous to have additional funds to develop the technology,” Koester says. “It’s one of these potential game changers.”

The goal is to get the graphene sensor to market as soon as possible, Kudva says, adding, “Philanthropy will definitely enable us to go faster and further.”

Reprinted with permission from the Minnesota Medical Foundation.