Newly-invented smart insulin patches could soon replace insulin injections. The patches are extremely small in size, and contain insulin in microscopic storage units as well as glucose-sensing enzymes. When the blood level is sensed to be too high, the insulin is released into the bloodstream. This method, as opposed to insulin injections, is not painful at all. The study has been published in the Proceedings of the National Academy of Sciences.
The insulin patch. Photo credits: The lab of Zhen Gu.
A team of researchers from the University of North Carolina and NC State have invented the first “smart insulin patch” that secretes the required doses of insulin into the blood of the one wearing it as per the demand; the patch does so upon detecting increases in blood sugar levels. The new invention is being hailed as the alternative to painful insulin injections.
The tiny patch is covered with hundreds of microneedles the size of an eyelash. Within these needles are microscopic sacks of insulin and glucose-sensing enzymes. These storage units of the hormone release their contents into the blood when the sugar concentration is found to be too high.
The researchers demonstrated that the painless patch could bring blood sugar concentration down in a mouse model with type 1 diabetes. This proved to be successful for 9 hours. More tests will be needed to determine whether using the patch on humans will generate positive results. But, the scientists are optimistic.
“We have designed a patch for diabetes that works fast, is easy to use, and is made from nontoxic, biocompatible materials,” said co-senior author Zhen Gu, PhD, a professor in the Joint UNC/NC State Department of Biomedical Engineering.
“The whole system can be personalized to account for a diabetic’s weight and sensitivity to insulin,” he added, “so we could make the smart patch even smarter.”
Diabetics across the world resort to insulin injection to keep the disease within control. These insulin shots are sometimes painful and inaccurate.
John Buse, MD, PhD, co-senior author of the PNAS paper and the director of the UNC Diabetes Care Center, said, “Injecting the wrong amount of medication can lead to significant complications like blindness and limb amputations, or even more disastrous consequences such as diabetic comas and death.”
The team of scientists had aimed to mimic the body’s own natural process of releasing insulin involving beta cells in the pancreas which are able to detect high blood sugar levels and release insulin accordingly.
“We constructed artificial vesicles to perform these same functions by using two materials that could easily be found in nature,” said PNAS first author Jiching Yu, a PhD student in Gu’s lab.
Two materials were used to create a new molecule to make the vesicles: hyaluronic acid or HA, and 2-nitroimidazole or NI. The resulting particles came together to form millions of vesicles, each 100 times smaller than the width of a human hair. The insulin and enzymes were then incorporated into each vesicle.
The vesicles were later paired with tiny needles which were created from the same hyaluronic acid used before. The needles were stacked together on a thin silicon strip. The patch was then placed onto the skin, with the microneedles penetrating into the surface, reaching into the capillaries underneath.
“The hard part of diabetes care is not the insulin shots, or the blood sugar checks, or the diet but the fact that you have to do them all several times a day every day for the rest of your life, said Buse, the director of the North Carolina Translational and Clinical Sciences (NC TraCS) Institute and past president of the American Diabetes Association. “If we can get these patches to work in people, it will be a game changer.”