Scientists at Zhejiang University, in partnership with researchers at the University of North Carolina at Chapel Hill, developed a “smart” type of insulin that successfully regulated blood glucose levels for up to a week after just one injection. The tests were carried out in mouse and mini-pig models. The study was published in the journal Nature Biomedical Engineering.
In the paper, the group describes how they created their insulin, how it works and how it performed when administered to diabetic rats and mini pigs.
Type I diabetes is a chronic condition in which the pancreas produces little or no insulin. Treatment for people with the disease includes a modified diet and regular insulin injections. Many diabetics have to inject themselves with insulin more than once a day, which is uncomfortable and even painful. Over time, the skin at the injection sites tends to harden, making it difficult to insert the needle.
In this new effort, scientists have created a new type of insulin that reacts with certain agents in the body, allowing automatic control of blood glucose levels over a long period of time.
The new smart insulin is a modified form of the insulin already in use — researchers added gluconic acid, which when injected into the body transforms into a complex when it binds to chemicals in the blood. Such complexes cause insulin to become trapped within a natural polymer, which results in changes in signaling. Different amounts of insulin are released depending on blood glucose levels. This, the scientists discovered, allowed more insulin to be automatically released into the blood when it was needed (such as after a meal) and less when it wasn’t.
The researchers tested the modified insulin on three minipigs and five mice — all engineered to have diabetes. Two of the minipigs received a high dose, while the third received a low dose.
By monitoring the test animals over the following weeks, the research team found that the minipig that received the low dose had the most stable glucose regulation compared to the other minipigs that received a high dose and also compared to the control minipigs. who received daily standard insulin injections.
The researchers suggest that their findings hold promise for a new type of treatment for patients with type I diabetes. Scientists will continue testing smart insulin on animals and, if all goes well, will move on to human trials.