For decades, researchers have tried to duplicate the function of beta cells, the tiny insulin-producing entities that don’t work properly in patients with diabetes. Insulin injections provide painful and often imperfect substitutes. Transplants of normal beta cells carry the risk of rejection or side effects from immunosuppressive therapies.
Now, researchers at the University of North Carolina at Chapel Hill and North Carolina State University have devised another option: a synthetic patch filled with natural beta cells that can secrete doses of insulin to control blood sugar levels on demand with no risk of inducing hypoglycemia.
The proof-of-concept builds on an innovative technology, the “smart insulin patch,” reported last year in the Proceedings of the National Academy of Sciences. Both patches are thin polymeric squares about the size of a quarter and covered in tiny needles, like a miniature bed of nails. But whereas the former approach filled these needles with manmade bubbles of insulin, this new “smart cell patch” integrates the needles with live beta cells.
Tests of this painless patch in small animal models of type-1 diabetes demonstrated that it could quickly respond to skyrocketing blood sugar levels and significantly lower them for 10 hours at a time. The results were published in Advanced Materials.
“This study provides a potential solution for the tough problem of rejection, which has long plagued studies on pancreatic cell transplants for diabetes,” said senior author Zhen Gu, PhD, assistant professor in the joint UNC/NC State department of biomedical engineering. “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.”
Beta cells typically reside in the pancreas, where they act as the body’s natural insulin-producing factories. In healthy people, they produce, store, and release the hormone insulin to help process sugar that builds up in the bloodstream after a meal. But in people with diabetes, these cells are either damaged or unable to produce enough insulin to keep blood sugar levels under control.