Spider web inspired implantable "string" could control diabetes
A team of researchers has developed a revolutionary new method for treating type 1 diabetes. Inspired by a spider's web, the team created an easily implantable nanoporous thread that can hold hundreds of thousands of insulin-producing islet cells and be easily removed when they need to come out.
Type 1 diabetes is characterized by the way the immune system destroys the body's insulin-producing cell clusters in the pancreas, called islets. For several years researchers have worked to find an effective way to transplant new, functioning insulin-producing islet cells into the body, but immune system rejection has been a major hurdle resulting in patients needed extreme immunosuppressive drugs.
A way to overcome the body rejecting the transplant is encapsulating the islet cells in a coating that protects them from the body's immune response. Of course the new problem raised by this method is that as these encapsulated cells are all disconnected from each other and nearly impossible to effectively remove from the body. A major issue when the cells either have a finite functional lifespan or have potentially cancerous side-effects.
"When they fail or die, they need to come out," says lead on the research 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."
This new method starts with a nanoporous polymer thread that is then covered with an alginate hydrogel which holds the insulin-producing islet cells. The hydrogel coating protects the islet cells from any immune system attack and the polymer thread allows the entire device to be easily implanted or removed through a simple laparoscopic surgical procedure.
Dubbed TRAFFIC (Thread-Reinforced Alginate Fiber For Islets enCapsulation), the team successfully demonstrated the thread in mouse models showing a one-inch length effectively reducing the animals' blood glucose levels to normal within two days of implantation. Ten-inch samples were also tested for retrievability in dogs with easy laparoscopic removal demonstrated one month after implantation.
"There have been other devices sort of like this, but this one seems to have so much promise," explains James Flanders, a veterinary surgeon working on the project. "It's minimally reactive, it protects the islet cells, it allows them to sense glucose, they don't attach to anything, and it can be easily removed. To me, it sounded like a win-win."
If further research shows this method to be effective in human experiments it could be applied to a variety of other hormone-deficient diseases and endocrine disorders. The novel, scalable, and easily retrievable method is potentially game-changing in how it offers a way to deliver new cell mass into a body while avoiding the problems of immune system rejection.
The study was published in the journal Proceedings of the National Academy of Sciences.
Source: Cornell University