Scientists claim a new implantable device with a built-in “oxygen factory” could soon replace insulin injections for people with type 1 diabetes.
Researchers at the Massachusetts Institute of Technology have developed a device the size of bubble gum that produces an endless supply of oxygen necessary to supply a diabetic’s body with key insulin-producing cells.
The device, tested on mice, has the potential to eliminate the need for diabetics to constantly monitor their blood sugar levels and inject themselves with insulin.
And scientists who plan to test the device on humans soon say it could also be adapted to treat other diseases that require repeated administration of proteins.
The minute device is about the size of a quarter. It is based on its ability to split water vapor into its components hydrogen and oxygen. It then stores this oxygen in a chamber to drive the release of transplanted islet cells that produce insulin
Dr. Daniel Anderson, a professor of chemical engineering at MIT who led the development of the device, said: “You can think of this as a living medical device made up of human cells that secrete insulin, along with an electronic life support system.”
The ability to manage type 1 diabetes without tedious and painful blood glucose testing and once-daily insulin injections would be a major win for the approximately two million Americans living with the disease.
Daily careful monitoring of blood sugar levels and manual injection of insulin are enough to keep a diabetic alive and healthy.
However, this process lacks the fine-tuned responsiveness of a non-diabetic’s body and does not replicate the body’s natural ability to control blood sugar levels.
Dr. Anderson said, “The vast majority of insulin-dependent diabetics inject themselves with insulin and do their best, but they don’t have healthy blood sugar levels.”
“If you look at their blood sugar levels, even in people who are very careful, they just can’t keep up with what a living pancreas can do.”
After MIT scientists encountered the problem of how to supply transplanted insulin-producing cells with enough oxygen to respond to drops in blood sugar, they found a way to break down water vapor in the body into its components, hydrogen and oxygen.
The oxygen then enters the device’s storage chamber, which nourishes transplanted insulin-producing cells, which are then able to respond immediately to a rise in blood sugar levels.
The system developed by MIT researchers also eliminates the need for immunosuppressants, which tame the body’s immune system so that it doesn’t attack the transplanted cells thinking they are foreign invaders.
Some patients with diabetes have already received transplanted cells from human cadavers that can control diabetes. At the same time, however, immunosuppressive medications must be taken to prevent the body from rejecting the implanted cells.
The device, developed by MIT scientists, was no larger than a quarter and was implanted just under the skin of diabetic mice with fully functioning immune systems.
A group of mice received the implant with the water vapor splitting membrane. The other group received a device with transplanted islet cells without supplemental oxygen to maintain the production of these cells.
Mice given the implant maintained normal blood sugar levels compared to healthy animals, while the mice that received the device became hyperglycemic — or with elevated blood sugar levels — within about two weeks.
The small device requires no cables or batteries and produces only a small voltage of about two volts through a phenomenon known as “resonant inductive coupling.”
A tuned magnetic coil outside the body – which could be worn as a patch on the skin – transmits energy to a small, flexible antenna inside the device, enabling wireless energy transfer.
Dr. Anderson said his team is excited about the progress the device has made, adding, “We’re really optimistic that this technology could ultimately help patients.”
When a medical device is implanted into the body, immune system attacks usually cause scar tissue to form, called fibrosis, which can reduce the effectiveness of a device.
Although this scar tissue formed around the implants used in the study, the device’s success in controlling blood sugar levels suggests that insulin was still able to diffuse out of the device and glucose into it.
This newly developed approach could also be used to boost cells that produce other types of proteins that need to be administered for longer periods of time, and the MIT researchers showed that their device can also keep cells that produce erythropoietin alive – a protein that stimulates red blood cell production.
Dr. Anderson said: “We are optimistic that it will be possible to create living medical devices that can remain in the body and produce drugs when needed.” There are a variety of diseases that require patients to ingest proteins exogenously; sometimes very often.
“If we can replace the need for infusions every two weeks with a single implant that can work over a long period of time, I think that could really help a lot of patients.”
The researchers now plan to test the device on larger animals and eventually on humans.
Siddharth Krishnan, a research scientist at MIT and lead author of the study, added: “The materials we used are inherently strong and durable, so I think this kind of long-term operation is within the realm of possibility, and it is .” We’re working on it.’