Science and Technology Daily, Beijing, September 9 (Reporter Zhang Jiaxin) One promising treatment for type I diabetes is to implant islet cells that produce insulin, which can save patients from frequent insulin injections. However, once the cells are implanted, they eventually run out of oxygen and stop producing insulin. To solve this problem, MIT engineers have designed a new implantable device that not only carries hundreds of thousands of islet cells, but also has its own on-board oxygen factory to produce oxygen by breaking down water vapor in the body. The related paper was published in the Proceedings of the National Academy of Sciences on the 18th.
The device uses a proton exchange membrane to produce oxygen indefinitely by splitting water. Proton exchange membranes were originally used to produce hydrogen in fuel cells, which can break down the water vapor present in large quantities in the body into hydrogen and oxygen, hydrogen diffusion is harmless, oxygen enters the storage chamber, through a thin layer of oxygen-permeable membrane to supply islet cells.
A significant advantage of this method is that it does not require any wires or batteries. The low voltage required to split the water vapor (about 2 volts) allows power to be wirelessly transmitted to a small flexible antenna inside the device through an extracorporeal coil that can be worn as a patch on the patient's skin.
The device is about 25 cents in size, and the researchers implanted it in diabetic mice. The results showed that it kept blood sugar levels stable in mice for at least a month. Now, they hope to create a larger version of the device, about the size of a stick of gum, that could eventually be tested on people with type I diabetes.
Often, when any kind of medical device is implanted in the body, the attack by the immune system can lead to a buildup of scar tissue, called fibrosis, which may reduce the effectiveness of the device. In this study, scar tissue did form around the implanted device, but the device's success in controlling blood sugar levels showed that insulin was still able to diffuse out of the device, promoting glucose absorption.
The researchers say the method could also be used to transport cells that produce other types of therapeutic proteins, such as those that produce erythropoietin, and keep them alive. Erythropoietin is a protein that stimulates the production of red blood cells.
If you have diabetics around you, you will find that they must have insulin in the items they carry with them. The insulin secretion of patients with type I diabetes is absolutely insufficient, and blood sugar cannot be effectively regulated, and can only rely on exogenous insulin to help. The method described in this article is not insulin, but islet cells. To keep the islet cells active, the implanted device also comes with an "oxygen factory" that doesn't require any wires or batteries. It does sound "once and for all". However, in order to make it work in the human body, it is necessary to take into account stability and long-term durability and equipment size miniaturization, and more trials and tests are needed to optimize it.