New Implant For Type 1 Diabetes Could Eliminate The Need For Insulin Injections

Credit: Lindsay France/Cornel University

For the more than 1 million Americans who live with type 1 diabetes, daily insulin injections are literally a matter of life and death. And while there is no cure, a Cornell-led research team has developed a device that could revolutionize management of the disease.

In Type 1 diabetes, insulin-producing pancreatic cell clusters (islets) are destroyed by the body’s immune system. The research group, led by assistant professor Minglin Ma from the Department of Biological and Environmental Engineering in the College of Agriculture and Life Sciences, has devised an ingenious method for implanting hundreds of thousands of islet cells into a patient. 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.

The findings were published in Proceedings of the National Academy of Sciences.

Doctoral students Alan Chiu, left, and Duo An hold a sample of TRAFFIC (Thread-Reinforced Alginate Fiber for Islets enCapsulation). In the background, left to right, are Minglin Ma, Dan Luo, Meredith Silberstein and Dr. James Flanders.

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.

And the ability to remove the transplant is key because of the potential of tumors forming when stem cell-derived, insulin-producing cells – the most promising cell source for type 1 diabetes cell therapies – are used.

“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.”

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.

That string: an ionized calcium-releasing, nanoporous polymer thread. The device starts with two sterile nylon sutures twisted in a helix, then folded over to facilitate the subsequent nanoporous structure coatings. Placed onto that thread is a thin layer of islet cell-containing alginate hydrogel, which adheres to the helical, nanoporous thread, similar to dew drops sticking to the spider silk. Alginate is a seaweed extract commonly used in encapsulated cell transplantation.

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.”

And since the thread is twisted and porous, the hydrogel won’t slip off as it would on a single, smooth piece of material. Fan and Silberstein were instrumental in modeling different options for the thread configuration.

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

“We only need two quarter-inch-long incisions,” Flanders said. “We inflate the abdomen with carbon dioxide, which gives us room to work, and then put in two ports – one for a scope that’s hooked to a camera, so we can see what we’re doing, and the other for a grasping device, which is how we introduce the implant.”

TRAFFIC’s large surface area promotes better mass transfer, Ma said, and diffusion is good because all the islet cells are near the surface. Current life span estimates for the thread are between six and 24 months, although more testing is necessary.

In mice, blood glucose levels were returned to normal two days after implantation of a one-inch length of TRAFFIC, and remained normal for at least three months when the experiment ended. Retrievability was tested in multiple dogs, with 10-inch samples being successfully implanted and removed laparoscopically.

Flanders, who performed surgical implantation in canines, said among the different dogs and devices tested there was either no or only minimal adhesion of the device to surrounding tissue upon removal.

This collaboration has produced a potentially game-changing medical device, he said.

“When Minglin first told me about this, I thought it was brilliant,” Flanders said. “There have been other devices sort of like this, but this one seems to have so much promise. 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.”


Via Cornell University

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9 days 3 hours ago

This sounds like a great advance and I’d like to get involved.
I’ve been on insulin for more that 25 years and would be happy to participate in any clinical trials that are planned.

9 days 2 hours ago

Our son has type1 and was diagnosed when he was 7. He is now 14. In addition he has Trisomy21 which affects his ability to manage his diabetes. We would love to get involved with this great work to help move it forward. What your talking about would provide him with much more freedom to deal with his diabetes and to enable him to move forward into adulthood without having to worry about changing pods every 3 days. Currently we deal with this for him so the freedom it would provide him would be unmeasurable

We really hope your great work is allowed to continue and develop.

10 days 2 hours ago

Would be wonderful of the team could create a solution for those suffering from Short Bowel Syndrome. 100s of people around the world live with daily pain and untold misery.

9 days 21 hours ago

Sure, of course. But for those autoimmune type 1 diabetic that live the fear of getting sudden blindness or loosing a limb, like me, it is already wonderful 🙂

Sue Helen McHaffey
Sue Helen McHaffey
9 days 18 hours ago
Not only do they have to worry about blindness or loss of limb, they live with the ever changing blood sugar levels that can go too high or too low which can kill them. Diabetics also run higher risks for heart disease. My daughter has been a diabetic since she was 11, that’s been thirteen years of more ups and downs than you can possibly imagine, more ER visits where she was on the brink of a coma because her blood sugar dropped in the early morning hours, between 2-3 am while she’s asleep because you cannot watch them 23/7, with loading her up and meeting the ambulance as it’s in route, which she has no recollection of, praying that this is not the day she dies because I’m not supposed to bury my child, she’s supposed to bury me. I have been an RN for over 30 years and… Read more »
6 days 9 hours ago

I was diagnosed with diabetes mellitus just before I was 2 years old. You’re not alone in the insanely brittle diabetic category. You actually sound EXACTLY like my mother and all the horrors she went through, to every last detail when I was growing up. BUT, have faith and one day you’ll be in control of the diasease, not it in control of you anymore. I can proudly say I’ve had the best bg readings probably ever, since I’ve gotten the dexcom g5 and the tslim pump. Dont give up, and have faith that God is in control.

David Yell
David Yell
4 days 8 hours ago

Sue thank you for so giving such a vivid picture of your daughters battle with this terrible disease. You have perfectly described my daughter and her battle as well. My daughter was hospitalized more times than I can count. She has gone through two pancreas transplants, the first failing even before she had left the hospital, the second failing suddenly and without warning after just one year. She is now on a smart version of the insulin pump which is good but far from perfect with many ups and downs. All the rejection medications have taken a toll on her body. She has made it to age forty by the grace of God, we pray continually for something new to come along and this seems to be an answer to prayer.

8 days 1 hour ago

My daughter is type 1 diabetic, she was diagnosed when shes 1 year old, now shes already 10 years old living under insulin injection since then.. we would love to get involved. Hoping the sooner the better… cant wait

1 day 8 hours ago

This would be great and to be involved in. I have been on insulin for 44 years now. I got it when i was 6 years levels have been all over the place to high and low from day one. they say im a brittle diabetes im at the last stages of it now. i do about 10 blood tests a day because i dont no when its down low anymore it would be around 3 or 2 before i no its down not safe to be like that you can pass away with it like that. i have about 13 things wrong with me now. It would be the best thing to not have insulin anymore. a lot off diabetes people out there would be a lot better off if they did not have to take insulin no more.