Image: Schematic mechanism of glucose-responsive smart insulin patch. (Credit: Zhen Gu Lab/UCLA)
Researchers at UCLA have developed a 24-hour smart insulin patch for patients with diabetes that monitors blood glucose levels and delivers the correct dose of insulin when required.
Insulin is produced by the pancreas and regulates blood glucose levels. Patients with Type 1 diabetes do not produce insulin and patients with Type 2 diabetes do not use insulin efficiently. Both types of diabetes can be managed by manually monitoring blood glucose levels and injecting insulin via needle and syringe, pen-like devices, or insulin pumps. Having to manually check insulin levels and administer insulin can greatly affect quality of life. Delays administering insulin and injecting too much can have serious consequences for patients.
There has been considerable research into glucose monitoring patches that can be fixed to the skin to deliver doses of insulin in response to rising blood glucose levels. While patches have been developed, they are expensive to manufacture and have limited insulin loading capacities. Those issues have been solved by the team at UCLA.
The smart insulin patch developed at UCLA is about the size of a quarter and is easy and cost-effective to manufacture. It contains microneedles less than 1 millimeter in length that deliver insulin on demand.
The UCLA patch was found to be effective in studies on mice and minipigs. A patch a quarter of the size of the one developed for treating diabetes in humans lasted for more than 20 hours in a 55lb minipig with type 1 diabetes.
The transdermal patch features a non-degradable glucose-responsive polymeric matrix and microneedles loaded with insulin. When fixed to the skin, phenylboronic acid units within the matrix form glucose–boronate complexes under hyperglycemic conditions. This creates a negative charge that causes the matrix to swell, weakening electrostatic interactions between the negatively charged insulin and polymers thus triggering the rapid release of insulin. As blood glucose levels return to normal, insulin release slows and stops.
“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,” said study leader Zhen Gu, a professor of bioengineering at the UCLA Samueli School of Engineering.
It is hoped that the patch could one day be used by diabetes patients to make management of their condition much easier. The patch could also help prevent overdoses of insulin, which can lead to a dangerous fall in blood glucose levels, which can result in seizures, coma, and death.
The researchers say the patch has been accepted under the U.S. Food and Drug Administration’s Emerging Technology Program, which will speed up the regulatory process. An application has now been made for FDA approval of the patch in clinical trials.
You can read more about the study in the paper – Glucose-responsive insulin patch for the regulation of blood glucose in mice and minipigs – which was recently published in the journal Nature Biomedical Engineering. DOI: 10.1038/s41551-019-0508-y