This is a close up of microneedles with beta cells. Credit: Zhen Gu Lab, NC State / UNC
This new ‘smart cell patch’ is a proof of principle to treat millions of people with type-1 and advanced type-2 diabetes. 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,”. 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 humanmade 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.
Yanqi Ye, a graduate student in Gu’s lab, constructed the “smart cell patches” using natural materials commonly found in cosmetics and diagnostics. She stuffed the hundreds of microneedles with culture media and thousands of beta cells that were encapsulated into microcapsules made from biocompatible alginate. When applied to the skin, the patch’s microneedles poked into the capillaries and blood vessels, forming a connection between the internal environment and the external cells of the patch.
Ye also created “glucose-signal amplifiers,” which are synthetic nanovesicles filled with 3 chemicals to make sure the beta cells could “hear” the call from rising blood sugar levels and respond accordingly.
Gu’s group showed that blood sugar levels in diabetic mice quickly declined to normal levels. To assess whether the patch could regulate blood sugar without lowering it too much, the researchers administered a second patch to the mice. As they had hoped, repeated administration of the patch did not result in excess doses of insulin, and thus did not risk hypoglycemia. Instead, the second patch extended the life of the treatment to 20 hours. Further modifications, pre-clinical tests, and eventually clinical trials in humans will all be necessary before the patch can become a viable option for patients. http://news.unchealthcare.org/news/2016/march/scientists-create-painless-patch-of-insulin-producing-beta-cells-to-control-diabetes
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