A removable encapsulation device for implanting islet cells has been developed that could improve a budding type 1 diabetes treatment.
Islet cell encapsulation is a promising avenue of type 1 diabetes research, which enables hundreds of thousands of insulin-producing islet cells to be administered in patients, improving their long-term control and ceasing the need for insulin injections.
An existing problem with encapsulatio, however, is the requirement for immunosuppressant drugs, which carry a range of side effects such as reducing the body’s ability to fight off infections. While using hydrogel capsules can help to prevent the immune system from attacking the cells, these capsules are hard to remove.
Scientists at Cornell University, New York, have attempted to combat this problem by devising a method of implanting islet cells that enables cells to be more easily removed once they have either died, or failed. This, they say, can limit the possible lasting damage of the cells, such as the potential to form tumours.
By coating islets with a thin hydrogel and attaching them to a polymer thread, rather than using capsules, the cells can be more easily removed or replaced when they have been used by the body.
“When they fail or die, they need to come out,” said lead author Minglin Ma. “You don’t want to put something in the body that you can’t take out. With our method, that’s not a problem.”
Prof Ma and his team were inspired by the way water beads on a spider’s web. He explained: “You don’t have any gaps between capsules. With a spider’s silk, you still have gaps between the water beads. In our case, gaps would be bad in terms of scar tissue and the like.”
The potential of the device has already been demonstrated in animal studies, reversing induced type 1 diabetes in rats for up to four months. The device is retrieved through a minimally invasive laparoscopic (keyhole) surgery.
Currently no research has been conducted on humans, but the researchers are optimistic regarding the implant’s implications for future encapsulation trials.
“This encapsulation device may contribute to a cellular therapy for T1D because of its retrievability and scale-up potential,” they concluded.
The findings were published online in the journal Proceedings of the National Academy of Sciences in the United States of America.