MIT engineers have designed a new emergency implant to protect people with type 1 diabetes from life-threatening hypoglycemia.
A quarter-sized device sits under the skin and releases a dose of glucagon when blood glucose levels are too low. It can be manually activated or triggered wirelessly by sensors.
Hypoglycemia, or hypoglycemia, is a constant danger for people with type 1 diabetes. When glucose levels drop sharply, patients often rely on injecting glucagon, the hormone that sigrates the liver.
However, in many cases, patients may not recognize any signs of behavior, especially during sleep or during children.
“It's a small emergency device that can be placed under the skin and is ready to act if a patient's blood sugar levels drop too low,” says Daniel Anderson, professor of chemical engineering at MIT and senior author of the study.
“Our goal was to build a device that was always ready to protect patients from hypoglycemia.”
The new device was developed to help patients who miss warning signs or are unable to self-administer glucagon quickly. It also provides a backup if hypoglycemia occurs during sleep.
Signal-activated drug delivery
To develop the system, MIT researchers created a small drug reservoir using 3D printed polymers sealed with a heat-responsive shape memory alloy.
The metal components made of nickel titanium curl and open when they reach 40 degrees Celsius. This action releases powdered medicines stored inside.
The liquid glucagon has broken over time, so the team instead saved the powder version.
The implant includes antennas tailored to a specific radio frequency, allowing for external wireless activation. A small current heats the metal seal and releases the drug.
“One of the key features of this type of digital drug delivery system is the ability to talk to sensors,” said Siddharth Krishnan, the lead author of the study. “In this case, the ongoing glucose monitoring techniques used by many patients are easy for these types of devices to interface.”
Tested in diabetic mice
The team implanted the device into diabetic mice and pulled the trigger when blood sugar levels fell. Within 10 minutes, sugar levels were stable and remained in the normal range.
They also tested a powdered version of epinephrine. Ten minutes after activation, the drug circulated in the bloodstream, indicating an increase in heart rate, indicating potential use for heart attacks or severe allergic reactions.
In the trial, the devices remained intact for four weeks and continued to function after scar tissue formed around them.
Researchers are currently working to expand that timeline for more than a year.
“We don't know exactly what it is. We're working on establishing what the optimal lifespan is probably a year, a few years, and now,” Krishnan said. “But then you'll need to replace it.”
The team is planning further animal testing and aims to begin human testing within three years.
“It's really exciting to see our team achieve this and hope that one day we can provide a new paradigm more broadly to help diabetics and provide emergency care,” said Robert Langer, another author of the paper.
This study is published in Nature Biomedical Engineering.
