Insulin injections are painful, and millions of Americans who suffer from diabetes can attest to that. But this pain may soon be a thing of the past thanks to a new invention from researchers at the University of North Carolina and NC State.

This incredible team of researchers has now created a “smart insulin patch” which detects increases in blood sugar levels and secretes doses of insulin into the bloodstream as needed. The relatively hands-off method is a major breakthrough, as scientists have been trying for decades to make regular insulin injections for diabetics unnecessary.

Covered in natural beta cells, the simple synthetic patch would eliminate the pain of injections, and even take out the worry work of monitoring as well. Though it hasn’t been tested on humans as of yet, it’s already been shown to safely control the blood sugar levels of mice for at least 10 hours at a time.

Beta cells are typically found in the pancreas, where they produce insulin to help the body process excess sugar in the bloodstream after a meal. People with diabetes, however, have damaged beta cells, or aren’t capable of producing enough insulin to keep their blood sugar levels in check. This is why they require regular insulin injections.

The researchers initially presented the idea last year, but this new and improved version contains real, live beta cells as opposed to synthetic insulin. Kept safely outside of the patient’s body, the beta cells have no chance of being rejected by the immune system.

“We have designed a patch for diabetes that works fast, is easy to use, and is made from nontoxic, biocompatible materials,” explained co-senior author Zhen Gu, PhD, a professor in the Joint UNC/NC State Department of Biomedical Engineering. “The whole system can be personalized to account for a diabetic’s weight and sensitivity to insulin,” he continued, “so we could make the smart patch even smarter.”

Gu created “microneedles” that poke into capillaries and connect with live, cultured beta cells and a patient’s bloodstream. The team of researchers also created “glucose-signal amplifiers,” which respond to rising blood sugar levels and inform the beta cells of this occurrence instantly.

“This study provides a potential solution for the tough problem of rejection, which has long plagued studies on pancreatic cell transplants for diabetes,” said Gu. “Plus it demonstrates that we can build a bridge between the physiological signals within the body and these therapeutic cells outside the body to keep glucose levels under control.”

To avoid the hazard of insulin injections, where diabetics can often give themselves too little or too much — which can result in hypoglycaemia, blindness, comas, and even death — the researchers added a second patch onto mice with regulated blood sugar levels. The new patch didn’t produce any extra insulin as they had hoped.

“Managing diabetes is tough for patients because they have to think about it 24 hours a day, seven days a week, for the rest of their lives,” explained one of the researchers, John Buse. “These smart insulin approaches are exciting because they hold the promise of giving patients some time off with regards to their diabetes self-care. It would not be a cure but a desperately needed vacation.”