A new implantable device with an inbuilt “oxygen factory” could soon replace insulin injections for people with diabetes, scientists claim.
Researchers in America have developed a new device the size of a stick of chewing gum that could be implanted in diabetics to control their blood sugar levels.
The device, tested on mice, could eradicate the need for diabetics to constantly monitor their blood sugar levels and inject themselves with insulin.
And scientists, who soon plan to test the device on humans, say it could also be adapted to treat other diseases requiring repeated deliveries of proteins.
The study, published in the journal Proceedings of the National Academy of Sciences, sought to create a long-lasting implantable device which can replace insulin injections.
Most people with Type 1 diabetes have to monitor their blood sugar levels carefully and inject themselves with insulin at least once a day.
But this process does not replicate our body’s natural ability to control our blood sugar levels.
A better alternative is to transplant cells that produce insulin whenever they detect surges in blood sugar levels.
Some patients with diabetes have already received transplanted cells from human corpses which can control diabetes – but immunosuppressive drugs preventing the body from rejecting the implanted cells must be taken simultaneously.
Another possibility preventing the need for immunosuppressive drugs is to house the implanted cells in a device which protects cells from the immune system.
However, the issue with this method lies in finding a reliable oxygen supply for the protected cells.
Some existing devices feature an oxygen chamber for cells, but this requires periodic reloading.
The study team from the Massachusetts Institute of Technology sought to create a device that could generate an unlimited supply of oxygen.
They used a proton-exchange membrane – a technology originally deployed to generate hydrogen in fuel cells – located within the device to ‘split’ water.
The membrane splits water vapor into hydrogen, which diffuses harmlessly away, and oxygen, which goes into a storage chamber that feeds the islet cells through a thin, oxygen-permeable membrane.
This method requires no wires 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 patch on the skin – transmits power to a small, flexible antenna within the device, allowing a wireless power transfer.
The resulting device, around the size of a U.S. quarter or a ten pence piece, was tested in diabetic mice.
One group had the device with the oxygen-generating membrane implanted, whilst another received a device containing islet cells without the same ‘oxygen factory’ membrane.
The devices were implanted just under the skin of the mice, which each had fully functional immune systems.
The mice with the oxygen-generating device were found to be able to maintain normal blood sugar levels comparable with healthy animals.
Those with the nonoxygenated device, however, became hyperglycemic – or with elevated blood sugar levels – within around two weeks.
Dr. Daniel Anderson, MIT Chemical Engineering professor and senior author of the study, said his team were excited about the progress the device has made.
“You can think of this as a living medical device that is made from human cells that secrete insulin, along with an electronic life support-system,” he said.
“We’re excited by the progress so far, and we really are optimistic that this technology could end up helping patients.
“The vast majority of diabetics that are insulin-dependent are injecting themselves with insulin, and doing their very best – but they don’t have healthy blood sugar levels.
“If you look at their blood sugar levels, even for people that are very dedicated to being careful, they just can’t match what a living pancreas can do.”
Typically, when a medical device is implanted in the body, attacks by the immune system lead to a buildup of scar tissue called fibrosis, which can reduce a devices’ effectiveness.
This scar tissue did form 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 needed to be given over long periods of time and the MIT researchers showed that their device could also keep alive cells that produce erythropoietin – a protein that stimulates red blood cell production.
“We’re optimistic that it will be possible to make living medical devices that can reside in the body and produce drugs as needed.
“There are a variety of diseases where patients need to take proteins exogenously; sometimes very frequently.
“If we can replace the need for infusions every other week with a single implant that can act for a long 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.
“The materials we’ve used are inherently stable and long-lived, so I think that kind of long-term operation is within the realm of possibility, and that’s what we’re working on,” Siddharth Krishnan, MIT Research Scientist, a lead author on the study said.
“We are very excited about these findings, which we believe could provide a whole new way of someday treating diabetes and possibly other diseases,” Dr. Robert Langer said, the David H. Koch Institute Professor at MIT and a member of the Koch Institute, was equally optimistic about what the device could achieve in the future.
Produced in association with SWNS Talker
