Removable Implant For Treatment of Type 1 Diabetes

Highlights

• TRAFFIC or Thread-Reinforced Alginate Fiber For Islets enCapsulation can help treat type 1 diabetes.
• The thread is a calcium-releasing, nanoporous polymer and is coated with islet cells that produce insulin.
• Through minimally invasive laparoscopic surgery, the thread can be implanted in the peritoneal cavity.

Implanting stem cell-derived, insulin-producing islet cells can soon be an alternative to insulin therapy for type 1 diabetics. Usually, type 1 diabetics need daily insulin injections to keep their blood sugar levels in check. Though a necessity, the injections are painful and there are hardly few other treatment options. Considering the issue, a Cornell University-led research team has developed a device that could revolutionize the management of the disease.

The research group, led by assistant professor Minglin Ma from the Department of Biological and Environmental Engineering, has devised an ingenious method for implanting hundreds of thousands of islet cells into a patient to facilitate insulin secretion. They are protected by a thin hydrogel coating and, more importantly, the coated cells are attached to a polymer thread and can be removed or replaced easily when they have outlived their usefulness.

TRAFFIC - Insulin Cells Embedded in a Thread

Taking inspiration from the way water beads on a spider's web, Ma and his team first attempted to connect the islet cell-containing capsules through a string but realized that it would be better to put the hydrogel layer uniformly around a string instead. The string is an ionized calcium-releasing, nanoporous polymer thread.

This thread - which the group has dubbed TRAFFIC (Thread-Reinforced Alginate Fiber For Islets enCapsulation) - was inspired by a spider's web but, according to Ma, is even better because the hydrogel covers the thread uniformly.

"You don't have any gaps between capsules," he said. "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."

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This therapy would involve minimally invasive laparoscopic surgery to implant approximately six feet of hydrogel-coated thread into the patient's peritoneal cavity.

Drawback of Other Treatments

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Transplantation of stem cell-derived, insulin-producing islet cells is an alternative to insulin therapy, but that requires long-term immunosuppressive drug administration. One well-researched approach to avoid the immune system's response is to coat and protect the cells in tiny hydrogel capsules, hundreds of microns in diameter. However, these capsules cannot be taken out of the body easily, since they're not connected to each other, and there are hundreds of thousands of them.

The ability to remove the transplant is key because of its potential to form tumors. "When they fail or die, they need to come out," Ma said. "You don't want to put something in the body that you can't take out. With our method, that's not a problem."

Facts on Type 1 Diabetes

• Nearly 1.25 million Americans are living with T1D, including about 200,000 youth (less than 20 years old) and more than 1 million adults (20 years old and older).
• Each year 40,000 people are diagnosed with type 1 diabetes
• 5 million people in the U.S. are expected to have T1D by 2050, including nearly 600,000 youth.
• Between 2001 and 2009, there was a 21 percent increase in the prevalence of T1D in people under age 20.
• In the U.S., there are $14 billion in T1D-associated healthcare expenditures and lost income annually.
• Less than one-third of people with T1D in the U.S. are consistently achieving target blood-glucose control levels.

Reference

1. Minglin Ma, Dan Luo ,Wei Song, Jason Lu, Yehudah Pardo, Dahua Shou, Ling Qi, Yewei Ji. ‘Spider's web inspires removable implant that may control type 1 diabetes.’ Proceedings of the National Academy of Sciences (2017).
2. http://www.jdrf.org/about/what-is-t1d/facts/

Source-Medindia