Diabetes is one of the most pressing health problems of our time, and now Swedish scientists have demonstrated a new way to control the disease. It turns out that the eye may be an effective place to implant insulin-secreting cells to control blood sugar levels.
The immune system of people with type 1 diabetes mistakenly attacks the insulin-producing cells in the pancreas, causing the body to be unable to regulate blood sugar levels, causing a series of health problems.
One promising emerging treatment involves growing new pancreatic cells from a patient's stem cells, loading them into a device and implanting them into the body. Human clinical trials have shown the therapy to be successful, but there's one major problem - the immune system sees the device as foreign and rejects it. Immunosuppressive drugs can address this problem, but can also leave patients vulnerable to infections and other illnesses.
Now, scientists at Sweden's KTH Royal Institute of Technology and Karolinska Institutet have demonstrated a way to avoid implant rejection. Previous studies have implanted the device under the skin, but in the new study, the team implanted it into the eye. While this sounds unpleasant, its main advantage is that there are no immune cells in the eye that react adversely to the implant. In addition, the eyeball is close to blood vessels, so insulin can quickly enter the bloodstream. Scientists can easily monitor the function of insulin just by looking at the eyeball.
In tests, the researchers developed a wedge-shaped device 240 microns long and implanted it in mice in the anterior chamber of the eyeball - the space between the cornea and iris. The device contains tiny organs in the form of pancreatic islets that produce insulin.
Woutervander Wijngaart, co-corresponding author of the study, said: "We designed this medical device to house living micro-organs in a micro-cage and introduced flap-gate technology to avoid additional fixation requirements."
In tests on mice, the team found that the device remained immobilized over several months of experiments. The cells quickly integrated with the eye's blood vessels and functioned normally during the experiment.
This proof-of-concept study shows that the eye is an ideal location for cell therapies to treat diabetes and other diseases.
Anna Herland, first author of the study, said: "Our study is a first step towards advanced medical microdevices that can both locate and monitor the function of transplanted cells. Our design will make it possible to integrate and use more advanced device functions in the future, such as integrated electronics or drug release."
The research was published in the journal Advanced Materials.