Researchers at the University of North Carolina at Chapel Hill (UNC) and North Carolina State University (NC), have designed a synthetic patch impregnated with live beta cells, capable of secreting insulin in response to rising blood glucose levels. According to its inventors, the patch carries no risk of hypoglycemia – a dangerous condition for diabetics in which blood sugar drops to below healthy levels.
Pancreatic beta cells are nonfunctional in patients with diabetes, so those with the type 1 form of the disease must inject insulin in order to regulate their blood glucose levels. Researchers have previously attempted to replace a patient’s beta cells with functional transplants, however these procedures carry a risk of rejection, and patients must take long courses of immunosuppressant drugs in order to prevent this occurrence.
This proof-of-concept design is an improvement on the group’s previous smart insulin patch – the details of which were published last year in the journal, PNAS. Unlike the previous iteration, the current design includes living beta cells which secrete insulin in much the same way as endogenous pancreatic cells would.
The original prototype contained insulin-filled microneedles which would allow insulin to flow into the capillaries just below the surface of the skin. Both patches share a similar design consisting of a thin polymeric square covered in tiny, pain-free needles.
The researchers tested the patch in small animal models of type 1 diabetes. They found the device was capable of rapidly responding to increasing blood sugar levels, and could sustain a controlled response for 10 hours. The results of this study were published in the journal, 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 Dr. Zhen Gu, assistant professor in the joint UNC/NC State department of biomedical engineering, and senior author on the publication. “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.”
In order to test whether the patch carried the risk of overdosing with insulin – potentially causing hypoglycemia – the researchers applied a second patch to the mice being studied. Not only did the second patch not lead to over-administration of insulin, but it actually served to prolong the life of the treatment to 20 hours.
It’s estimated that over 387 million people are affected by diabetes across the world, with projections estimating that this figure will grow to 500 million by 2030. Patients with type 1 diabetes – and some with more advanced forms of type 2 – must control their blood sugar levels by injecting with insulin throughout the day.
“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 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. “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.”