Bioengineers at UCLA and several other universities have developed a smart insulin-delivery patch that they say could one day monitor and manage glucose levels in people with diabetes and deliver necessary insulin dosage.
The adhesive patch, which is about the size of a quarter, is simple to manufacture and intended to work for 24 hours before needing to be replaced, according to Zhen Gu, a professor of bioengineering at the UCLA Samueli School of Engineering.
Gu led a study, published in Nature Biomedical Engineering, describing the research in which the patch was tested on mice and pigs.
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"Our main goal is to enhance health and improve the quality of life for people who have diabetes," Gu said. "This smart patch takes away the need to constantly check one's blood sugar and then inject insulin if and when it's needed. It's mimicking the regulatory function of the pancreas, but in a way that's easy to use."
The smart patch has doses of insulin pre-loaded in very tiny microneedles, less than one millimeter in length, that deliver the medicine quickly when blood sugar levels reach a certain threshold. When blood sugar returns to normal, its insulin delivery also slows down, according to the researchers.
The advantage of the patch, they say, is that it could help prevent insulin overdoses, which can lead to hypoglycemia, seizures, coma or even death.
"It has always been a dream to achieve insulin-delivery in a smart and convenient manner,'' said study co-author John Buse, director of the Diabetes Center and the Translational and Clinical Sciences Institute at the University of North Carolina at Chapel Hill School of Medicine. "This smart insulin patch, if proven safe and effective in human trials, would revolutionize the patient experience of diabetes-care."
Insulin, a hormone naturally produced in the pancreas, helps the body regulate glucose, which comes from food consumption and provides the body with energy. Insulin is the molecular key that helps move glucose from the bloodstream to the cells for energy and storage.
Diabetes occurs when a person's body does not naturally produce insulin (Type 1 diabetes), or does not efficiently use the insulin that is produced (Type 2). In either case, a regular dosage of insulin is prescribed to manage the disease, which affects more than 400 million people worldwide.
The treatment for the disease hasn't changed much in decades in most of the world, with patients drawing their blood using a device that measures glucose levels and then self-administering a necessary dose of insulin. The insulin is injected with a needle and syringe, a pen-like device, or delivered by a portable insulin pump.
According to UCLA, the microneedles used in the patch are made with a glucose-sensing polymer that's encapsulated with insulin. Once applied on the skin, the microneedles penetrate under the skin and can sense blood sugar levels. If glucose levels go up, the polymer is triggered to release the insulin.
The microneedle is smaller than a regular needle used to draw the blood, and it also does not reach as deeply so it is less painful than a pinprick, according to the researchers, who envision that the patch could also be adapted with different drugs to manage other medical conditions.
In the researchers' experiments, one quarter-sized patch successfully controlled glucose levels in a 55-pound pig with type I diabetes for about 20 hours.
The study, supported by UCLA-based startup Zenomics, also included authors from North Carolina State University, the Massachusetts Institute of Technology and Boston Children's Hospital.
According to UCLA, the technology has been accepted into the U.S. Food and Drug Administration's Emerging Technology Program, which provides assistance to companies during the regulatory process.
The researchers are applying for FDA approval for human clinical trials, which they anticipate could start within a few years.