Scientists create insulin-producing patch made with beta cells to replace insulin injection

Print 21 March 2016
Stacy Lawrence / Fierce Medical Devices

A depiction of the beta cell patch, cross-section--Courtesy of UNC/NC State

In the last few years, researchers have gotten very good at mass-producing pancreatic beta cells that produce sufficient insulin to offer improvement for diabetic patients. But now, they're focused on inventing and testing the means to use these beta cells in a way that effectively introduces insulin into the system--while simultaneously protecting the cells from a patient's immune system.

University of North Carolina at Chapel Hill and North Carolina State University scientists have created a novel approach---incorporating natural, insulin-secreting beta cells that secrete doses of insulin on demand into a tiny, painless needle-filled synthetic patch, thereby eliminating the risk of inducing hypoglycemia for Type 1 diabetics that comes with the use of insulin injections.

The researchers have published preclinical data on the beta cell patch in Advanced Materials. In small animal models, the patch was able to quickly respond to skyrocketing blood sugar levels--significantly lowering them for 10 hours at a time.

"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," said co-author Dr. John Buse, professor of medicine at the UNC School of Medicine and director of the UNC Diabetes Care Center and the NC Translational and Clinical Sciences Institute, in a statement. "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."

Last year, researchers from these institutions also debuted a smart insulin patch--but that was based on bubbles of man-made insulin, rather than insulin produced on-site via live beta cells like this latest iteration. Both, however, are thin polymeric squares about the size of a quarter and covered in miniature needles similar to a super-tiny bed of nails.

"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, 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."

The beta cell patches were created out of natural materials commonly used in cosmetics and diagnostics. The hundreds of microneedles, each about the size of an eyelash, were hand-stuffed with culture media and thousands of beta cells. They were encapsulated in microcapsules made of biocompatible alginate.

After application to the skin, the microneedles poke into the capillaries and blood vessels thereby connecting the internal and external cells of the patch. Also, part of the process was the creation of glucose signal amplifiers, which are synthetic chemical-based nanovesicles that enable the beta cells to detect rising blood sugar levels and respond effectively.

More preclinical testing and modifications will be required before the researchers are ready for clinical testing in humans. The research was backed by the National Institutes of Health, the American Diabetes Association and the National Science Foundation.

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