Millions of people suffering from diabetes could be spared painful injections after scientists invented a smart patch which monitors glucose levels and delivers insulin automatically via hundreds of micro-needles.
The high-tech device, which sticks to the skin like a plaster, can detect even slight increases in blood sugar levels meaning that tiny doses of insulin can be given when needed.
The patch – a thin square no bigger than a postage stamp – is covered with more than one hundred tiny needles, each about the size of an eyelash.
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These “microneedles” are packed with microscopic storage units for insulin and glucose-sensing enzymes that rapidly release their cargo when blood sugar levels get too high.
Although it has only been tested on mice, the developers at the University of North Carolina say it could be a ‘game changer’ for humans.
“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 Prof Zhen Gu, of the Department of Biomedical Engineering.
“The whole system can be personalized to account for a diabetic’s weight and sensitivity to insulin so we could make the smart patch even smarter.”
The tiny needles seen under a microscope Credit: University of North Carolina
It is though that diabetes affects nearly four million people in Britain although around 850,000 are currently undiagnosed.
Patients with type 1 and advanced type 2 diabetes are forced to keep their blood sugar levels under control with regular finger pricks and repeated insulin shots, a process that is painful and imprecise.
“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,” said Dr John Buse, one of the paper’s authors and director of the University of North Carolina Diabetes Care Centre.
The new patch works by copying the body’s own natural insulin generators, known as beta cells. Beta cells make and store insulin, deciding when it should be released and in what quantity.
The team developed ‘intelligent nanoparticles’ made of tiny bubbles which each contain a small amount of insulin and enzymes designed to sense glucose. When they sense a spike in blood sugar the bubbles disintegrate releasing specific amounts of insulin depending on how much glucose was present.
They then built the balls into an array of tiny needles which can sit on a patch in the skin.
When this patch is placed onto the skin, the microneedles penetrate the surface, tapping into the blood flowing through the capillaries just below.
“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, added Prof Buse.
“If we can get these patches to work in people, it will be a game changer.”
Their eventual goal is to develop a smart insulin patch that patients would only have to change every few days.
Dr Richard Elliott, of the Diabetes UK Research Team said: “This research involved mice and is still at an early stage, so further studies and clinical trials in humans will be needed to find out if this promising new approach might help to simplify existing techniques for managing blood glucose – which we know can be a painful daily chore for millions of people with diabetes.
“We will continue to follow progress in this area with interest.”
The research was published in the journal Proceeding of the National Academy of Sciences.