‘Smart’ Insulin Patch Shows Promise for Diabetes

A Novel Technology

Instead of inventing another completely manmade system, the researchers chose to emulate beta cells. They constructed artificial vesicles to perform the same functions as beta cells by using two materials commonly found in nature.

The first material was hyaluronic acid, a natural substance that is an ingredient of many cosmetics. The second was 2-nitroimidazole, an organic compound commonly used in diagnostics. The researchers connected the two to create a new molecule, with one end that was hydrophilic and one end that was hydrophobic. A mixture of these molecules self-assembled into a vesicle, with the hydrophobic ends pointing inward and the hydrophilic ends pointing outward. 

The final product was millions of bubble-like structures — each 100 times smaller than the width of a human hair — and into each of these vesicles is inserted a core of solid insulin and enzymes specially designed to sense glucose.

Rather than rely on the large needles or catheters that had beleaguered previous approaches, the researchers decided to incorporate these balls of sugar-sensing, insulin-releasing material into an array of tiny needles.

Early Results

For their current investigation, the researchers gave one set of mice a standard injection of insulin and measured the blood glucose levels, which dropped down to normal but then quickly climbed back into the hyperglycemic range.

In contrast, when the researchers treated another set of mice with the microneedle patch, they saw that blood glucose levels were brought under control within 30 minutes and stayed that way for several hours.

In addition, the researchers found that they could tune the patch to alter blood glucose levels only within a certain range by varying the dose of enzyme contained within each of the microneedles. They also found that the patch did not pose the hazards that insulin injections do, as injections can send blood sugar plummeting to dangerously low levels when administered too frequently.

Clinical Implications

Buse explained that the hard part of diabetes care is not the insulin shots, the blood sugar checks or the diet. Rather, it is the fact that you have to do them all several times a day every day for the rest of your life, he said, noting that if the clinical trials are successful in the future then this smart patch will be “a game-changer.”

This new technology not only sounds very promising but also makes a lot of sense, according to Martin Myers, MD, who is a professor of medicine in the division of metabolism, endocrinology and diabetes at the University of Michigan in Ann Arbor. He said integrating this new technology into the diabetes pharmacopoeia would be a significant advance. Compliance, he noted, is always a major issue, and so this would eliminate much of that problem.

“This is a smart way go,” Myers said in an interview with Endocrinology Advisor. “The real potential value of this is that when people with diabetes are not eating, they take a long-acting insulin and if you have taken too much, then the blood sugar levels go too low. So, this will be smarter than that, and will eliminate the problem of low blood sugar that you see when using long-acting insulin. Hypoglycemia would be less of a problem, but that will have to be proven.”

*Image courtesy of the lab of Zhen Gu, PhD.

Reference

  1. Yu J et al. Proc Natl Acad Sci. 2015;112(27):8260–8265.