Rolf Bodmer, PhD: Hello. I'm Dr. Rolf Bodmer, Professor and Program Director of Development and Aging in the Del E. Webb Neuroscience, Aging and Stem Cell Research Center here at the Sanford-Burnham Medical Research Institute.
Today, I will be talking with my colleague, Dr. Pamela Itkin-Ansari, who is Adjunct Assistant Professor in the Center, about her work and what she and her team are doing in developing a new approach to treating type 1 diabetes.
To counter the loss of functioning islet cells in patients with type 1 diabetes, Pamela and her team have designed a device containing stem cell-derived beta cells that produce insulin and act like a mini-pancreas when transplanted into diabetic mice, thereby curing their disease.
Pamela, tell me, what are the current challenges in treating in type 1 diabetes?
Pamela R. Itkin-Ansari, PhD: Currently, patients with type 1 diabetes take insulin shots a few times a day after checking their blood sugar. But a normal pancreas tests the blood sugar every second of the day and adjusts the precise amount of insulin needed. So the problem is that most of the day, the diabetes patient's blood sugar is out of control. Eventually, this leads to bad complications, and currently, as a country, we are spending $174 billion on diabetes care.
Dr. Bodmer: This implantable device that you are working with -- how is it more advantageous than other therapies?
Dr. Itkin-Ansari: Our hope is that it will replace the cells that the patients are missing. This has been tried in a couple of ways, first with whole pancreas transplant. Then, because the islets that make insulin are actually only a small part of the pancreas, people have tried purifying the islet cells and just transplanting those. But we do not have enough cells, and patients need to receive immunosuppressive drugs for the rest of their lives. Our hope is that we can hide the transplanted cells from the patient's immune system and leave the immune system intact to fight infections.
Dr. Bodmer: What is in this device, and how does it help to treat type 1 diabetes? How is it better than current treatments?
Dr. Itkin-Ansari: The idea of an encapsulation device is that we are hiding cells from the immune system. Essentially, the cells are put inside a cage so that the immune cells cannot get in, but there have to be pores that allow nutrients in and out; allow waste products in and out; and, very important, allow the insulin-producing cells inside to sense blood sugar and release insulin out of the device.
Dr. Bodmer: Can you show us such a device and tell us more about what encapsulation technology is all about?
Dr. Itkin-Ansari: Here is an example of one. A device this size, when filled with insulin-producing cells, could cure diabetes in a mouse. I have been working with local companies to enlarge it so that it would be appropriate for human trials.
Dr. Bodmer: What types of cells are in this device?
Dr. Itkin-Ansari: When we started, we did studies with mouse islets, and we wanted to know whether human cells would function well in the device. At about this time, stem cell technology was taking off. Our hope was that eventually, we could have a virtually unlimited supply of cells from stem cells, because with the islets that are purified from cadavers right now for islet transplants, we can perform transplant in only very few people.
Working with a local biotechnology company, they partially developed naive stem cells into pancreas cells, but these were not yet mature insulin-producing cells. What we have been able to show recently that we are so excited about is that when we encapsulate those cells in the device and transplant it just under the skin, the cells mature into perfectly functioning insulin-producing cells. We are talking about an unlimited source of cells, potentially, and a device that keeps us from the need to put patients on long-term immunosuppression. I think that is going to be an ideal therapeutic approach.
One of the advantages we hope to give diabetic patients is that we may be able to transplant the device just under the skin; that would make the therapy minimally invasive, which would be a real plus.
Dr. Bodmer: How long can it stay there?
Dr. Itkin-Ansari: That is a great question. We kept cells inside the device for up to 1 year, and the cells survived and functioned well, but now we need to see just how long the cells can survive and whether they can survive well under all conditions.
Of course, it is a trade-off. You would not want to have to remove devices and put in new ones on a regular basis. Our hope is that we transplant cells and they last for a long time.
Dr. Bodmer: One year over every day is a big advantage.
Dr. Itkin-Ansari: It could be a very big advantage, especially because there are 2 sides to the problem right now. There is the ultimate problem that the therapy is not good enough, and that is why people develop complications. The flip side of it is that for children with type 1 diabetes, it is a full-time job. I know a 6-year-old who has already had 16,000 finger pricks to check his blood sugar, and 10,000 insulin shots. It is a very large personal burden for him and for his family to keep him healthy. We would love to make his childhood more carefree.
Dr. Bodmer: How long will it take until this new device can reach the clinic?
Dr. Itkin-Ansari: That is always the big question. We worked for a long time with partners in biotechnology to get stem cells to work in the device. What we do in the laboratory is a relatively small-scale compared with what we eventually need for patients. The first phase is scale-up -- getting to the right number of cells that can be grown and the right size of a device for human therapies. Then we need to figure out how to move on to trials in people and make sure this is working.
Dr. Bodmer: So that is going to take a while.
Dr. Itkin-Ansari: It does take a while, yes. The US Food and Drug Administration is aware of how well the work is going, and I think this is really being understood to be the next phase of diabetes therapy.
Dr. Bodmer: As you can see, the work being done in Dr. Itkin-Ansari's laboratory is a first step in bringing new treatments to the clinic.
Thank you for joining us today. I hope you will join us for additional programs in the Developments to Watch Series on Medscape.
Sanford-Burnham Medical Research Institute and Medscape
Cite this: Rolf Bodmer, Pamela R. Itkin-Ansari. Treating Type 1 Diabetes With Stem Cells: A New Way Forward - Medscape - Jan 03, 2013.