Scientists say 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 gum-sized device that produces an endless supply of oxygen needed to infuse a diabetic’s body with crucial insulin-producing cells.
The device, tested in mice, has the potential to eradicate the need for diabetics to constantly monitor their blood sugar levels and inject themselves with insulin.
And the scientists, who soon plan to test the device in humans, say it could also be adapted to treat other diseases that require repeated deliveries of proteins.
The tiny 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 that oxygen in a chamber to drive the release of transplanted islet cells, which produce insulin.
Dr. Daniel Anderson, a professor of chemical engineering at MIT and a leader in developing the device, said: “You can think of this as a living medical device made of human cells that secrete insulin, along with an electronic life support system. “.
The ability to manage type 1 diabetes without the tedious and painful processes of measuring blood sugar and injecting insulin once a day would mark a major victory for the approximately two million Americans living with the condition.
The daily regimen of meticulously monitoring blood glucose levels and manually injecting insulin is enough to keep a diabetic person alive and healthy.
But this process lacks the kind of fine responsiveness that a non-diabetic person’s body has and does not replicate the body’s natural ability to control blood sugar levels.
Dr Anderson said: “The vast majority of diabetics who are insulin dependent take insulin and do the best they can, but they don’t have healthy blood sugar levels.
“If you look at their blood sugar levels, even for people who are very dedicated to being careful, they just can’t match what a live pancreas can do.”
After encountering the problem of how to supply transplanted insulin-producing cells with enough oxygen to respond to drops in blood glucose, MIT scientists discovered a way to split the body’s water vapor into its component parts, hydrogen and oxygen. .
Oxygen then enters the storage chamber in the device that powers transplanted insulin-producing cells that can then respond to sudden increases in blood glucose levels.
The system the MIT researchers developed also negates the need for immunosuppressive drugs, which control the body’s immune system from attacking transplanted cells believing them to be foreign invaders.
Some patients with diabetes have already received transplanted cells from human cadavers that can control diabetes, but at the same time they must take immunosuppressive medications that prevent the body from rejecting the implanted cells.
The device the MIT scientists developed was no bigger than a quarter and was implanted in diabetic mice with fully functional immune systems just under the skin.
One group of mice received the implant with the membrane that divides water vapor. The other group received a device containing transplanted islet cells without supplemental oxygen to maintain the production of those cells.
Mice given the implant maintained normal blood glucose levels relative to healthy animals, while mice given the device became hyperglycemic (or high blood sugar) in about two weeks.
The small device requires no cables or batteries and only a small voltage of around two volts generated through a phenomenon known as “resonant inductive coupling.”
A tuned magnetic coil outside the body, which could be worn as a skin patch, transmits power to a small, flexible antenna inside the device, allowing for wireless power transfer.
Dr. Anderson said his team was excited about the progress the device has made, adding, “We’re really optimistic that this technology could end up helping patients.”
Typically, when a medical device is implanted in the body, attacks by the immune system cause a buildup of scar tissue called fibrosis, which can reduce the effectiveness of the device.
This scar tissue formed around the implants used in the study, but the device’s success in controlling blood glucose 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 deliver cells that produce other types of proteins that need to be administered for long periods of time, and the MIT researchers showed that their device could also keep alive cells that produce erythropoietin, a protein that stimulates the production of Red blood cells. .
Dr Anderson said: “We are optimistic that it will be possible to create living medical devices that can reside in the body and produce medicines as needed.” There are a variety of diseases in which patients need to take protein exogenously; sometimes very frequently.
“If we can replace the need for infusions every two weeks with a single implant that can work for a long time, I think that could help a lot of patients.”
The researchers now plan to test the device in larger animals and, eventually, humans.
MIT research scientist Siddharth Krishnan, lead author of the study, added: “The materials we’ve used are inherently stable and long-lasting, so I think that kind of long-term operation is within the realm of possibility, and That’s what we’re working on.’
