Smart insulin patch to control diabetes

Washington: Scientists have created asynthetic painless patch filled with natural insulin-producing cells that can control blood sugar levels on demand. For decades, researchers have tried to duplicate the function of beta cells, the tiny insulin-producing entities that do not 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, researchers said. Now, scientists from University of North Carolina (UNC) in the US 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. However, 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. "This study provides a potential solution for the tough problem of rejection, which has long plagued studies on
pancreatic cell transplants for diabetes," said Zhen Gu from UNC.

"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," said Gu. 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, researchers said.
However, in people with diabetes, these cells are either damaged or unable to produce enough insulin to keep blood sugar levels under control, they said.

Researchers constructed the "smart cell patches" using natural materials commonly found in cosmetics and diagnostics. They stuffed the hundreds of microneedles, each about the size of an eyelash, 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. The findings were published in the journal Advanced
Materials.