university of miami

Pioneering transplant sees type 1 diabetic free from insulin dependence

by Barbara Hewitt on September 14, 2015

Pioneering research in the United States has led to the first person with type 1 diabetes to receive a new islet transplant technique no longer needing to take insulin.

Wendy Peacock, 43, can now produce her own insulin after the new procedure as part of a trial conducted by the Diabetes Research Institute (DRI) at the University of Miami.

researcherThe new technique involved the implantation of islet cells within a biological scaffold and it means that she is completely free from being dependant on insulin since being diagnosed with type 1 diabetes at the age of 17.

Building on previous islet cell transplant research, the trial is working towards the development of a mini organ known as the DRI BioHub which allows people with type 1 diabetes to produce their own insulin by mimicking a healthy pancreas.

“The first subject is now completely off insulin with an excellent glucose profile. These are the best post-transplant results we’ve seen in an islet recipient. This was the first tissue engineered islet transplant using a biodegradable scaffold implanted on the surface of the omentum,” said Camillo Ricordi, director of the DRI and Professor of Biomedical Engineering, Microbiology and Immunology at the University of Miami Miller School.

“The technique has been designed to minimise the inflammatory reaction that is normally observed when islets are implanted in the liver or in other sites with immediate contact to the blood. The site is easily accessed by minimally invasive surgery, and more importantly, has the same blood supply and drainage characteristics of the pancreas where islets are originally found before they are destroyed in type 1 diabetes,” he added.

The biodegradable scaffold, one of the platforms for a DRI BioHub, is a combination of a patient’s own blood plasma and thrombin, a commonly used, clinical grade enzyme. When combined, these substances create a gel like material that sticks to the omentum and holds the islets in place.

The omentum is then folded over around the biodegradable scaffold mixture. Over time, the body will absorb the gel, leaving the islets intact, while new blood vessels are formed to provide critical oxygen and other nutrients that support the cellsí survival.

“The objective of this first trial is to show that these cells can function in this new transplant site, but demonstrating safety is paramount to all of us; safety first and then effectiveness,” said Rodolfo Alejandro, Professor of Medicine and director of the DRI Clinical Cell Transplant Programme.

“We hope that in the omentum, which is quite rich in blood vessels, vascularization is accelerated allowing more islets to survive and engraft, and that we can show that this site is both a safe and viable alternative as a transplant site on which to further the DRI BioHub projects,” he added.

Islet transplantation in the liver has allowed some other people to live without the need for insulin injections after receiving a transplant of donor cells but it has been known for years that itís not the ideal site and the liver will not accommodate a device for housing the islets. Also, people with type 1 diabetes who benefit from islet cell transplantation need to take immunosuppressant drugs to stop the immune system attacking the new, functional islet cells too and this carried a risk of illness and infection.

Ricordi is hopeful that technological developments in the future will remove the need for immunosuppressant therapy. “If these results can be confirmed, this can be the beginning of a new era in islet transplantation. Our ultimate goal is to include additional technologies to prevent the need for life long anti-rejection therapy,” he said.

“As any type 1 knows, you live on a very structured schedule. I used to do a mental checklist every day in my head; glucose tabs, food, glucometer, etc., and I don’t have to plan that anymore. Laying down at night and going to sleep and not having to worry about lows is something that is so foreign to me. It’s surreal to me. I’m still processing the fact that I’m not taking insulin anymore,” said Wendy.

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