What are "islets of Langerhans?"
What are "juvenile" and "adult" diabetes?
What goes wrong with islets in juvenile diabetes?
Do people die of diabetes?
Why don't insulin injections help?
Can the cells that make insulin be transplanted?
Does islet transplantation normalize blood sugar and cure diabetes?
How many islets are needed?
Can you overdose?
Why aren't all diabetics treated with islet transplants?
Then why not use the drugs that make possible kidney and liver transplantation?
Then what about some barrier or membrane to protect the islets from rejection?
Is the bio-artificial pancreas a new idea?
Why is it so difficult?
Why can't the islets survive?
Why will islet immunoisolation work now, when it has always failed in the past?
If individually encapsulated islets work, why do we need a sheet?
Does the Islet Sheet cure diabetes in animals?
How big will the sheet have to be to cure diabetes?
Where will the sheet go?
How long will the implant function?
Where will the islets come from?
How much could Islet Sheet Medical charge for a bio-artificial pancreas?
Will Islet Sheets help both juvenile diabetics and adult diabetics?
How can I participate in clinical studies?
When will clinical studies begin?
When will the Islet Sheet be available?

What are "islets of Langerhans?"

Clusters of cells in the pancreas regulating metabolism that secrete hormones including insulin. (Click here for micrographs of islets of Langerhans.)


What are "juvenile" and "adult" diabetes?

Abnormally high blood sugar defines both types of diabetes. Adult diabetes (Type 2 diabetes, non-insulin-dependent diabetes mellitus, or NIDDM), the more common form, is caused by a decline in tissue response to insulin. Juvenile diabetes (Type 1 diabetes, insulin-dependent diabetes mellitus, or IDDM), rarer but more severe, is caused by failure of islets to make sufficient insulin.

The current recommended names are "type 1" and "type 2" diabetes.


What goes wrong with islets in juvenile diabetes?

Islets are destroyed by an autoimmune reaction and cease making insulin. (Click here to see insulitis.)


Do people die of diabetes?

The lack of naturally secreted insulin allows blood sugar to become uncontrolled. Without insulin injections death comes in months from gross metabolic derangement. Even with insulin injections blood sugar are still higher and more variable than normal. These blood sugar levels damage the circulatory system, and people with diabetes typically die of vascular disease after many years of diabetes.


Why don't insulin injections help?

Insulin injections do help, but they are never as good as islets at controlling blood sugar. Studies show that the more carefully diabetics use insulin, the longer they live. Unfortunately, even the best control from careful insulin injections does not prevent morbidity (such as vascular decay) and premature death.


Can the cells that make insulin be transplanted

Yes. Islets can be liberated from the pancreas, then put into the liver or abdominal cavity of the diabetic. Click here for a detailed figure of human islet transplantation.


Does islet transplantation normalize blood sugar and cure diabetes?

Yes. Many people who have had their pancreases removed have subsequently had their diabetes cured by re-implantation of their own islets.


How many islets are needed?

About 350,000 fully functional islets are needed.


Can you overdose?

An overdose is impossible when islets can quickly sense blood sugar changes because they respond immediately. When blood sugar normalizes insulin secretion stops.


Why aren't all diabetics treated with islet transplants?

Because islets are rejected, like all transplanted tissue.


Then why not use the drugs that make possible kidney and liver transplantation?

There are four reasons. First, the drugs have side effects which are worse than the problems associated with insulin therapy, and such immunosuppressive drugs must be used for the remainder of the recipient's life. Second, islets are more susceptible to rejection than other organs. Third, human islets are so scarce that animal islets are needed, and immune suppression does not work with animal tissues. Fourth, islets are sensitive to the toxic effects of commonly used immunosuppressive drugs.


Then what about some barrier or membrane to protect the islets from rejection?

A device combining living islets that make insulin with an artificially constructed membrane for protection is called a bio-artificial pancreas and is the focus of our company. The Islet Sheet is the most advanced design for a bio-artificial pancreas. Click here to see a micrograph of a microencapsulated islet with a thin coating.


Is the bio-artificial pancreas a new idea?

No. Many have been tested, and all have been found deficient.


Why is it so difficult?

Basically, most devices have not allowed islet survival within the diabetic recipient.


Why can't the islets survive?

Usually because they do not get enough oxygen. Sometimes in a process called fibrosis the implant is covered with collagen fibers that prevent other nutrients from entering, too.


Why will islet immunoisolation work now, when it has always failed in the past?

Because the problem is now rightly understood. We know the properties required for a successful implant. Islet Sheet Medical has "backward engineered" its technology from a common sense analysis of the conditions required to maintain long-term life and function of transplanted islets.

Thin alginate encapsulated islets have been shown to prevent islet rejection.


If individually encapsulated islets work, why do we need a sheet?

Individually coated islets cure diabetes, like the sheet. But the individually coated islets cannot be retrieved. Doctors and regulatory bodies are very concerned that implants be retrievable in case there are problems. In addition, sheets can be made with greater efficiency and uniformity than coatings and permeability control is superior.

Finally, there are experimental advantages to sheets. They can be perfected faster. Click here for a more detailed discussion.


Does the Islet Sheet cure diabetes in animals?

In February, 2000 ISM began investigations designed to show that the Islet Sheet can cure diabetes in dogs, the best animal model of human type 1 diabetes. Results so far are encouraging. Click here to see the latest results.


How big will the sheet have to be to cure diabetes?

A few sheets the size of the one to the right would be sufficient. (Click here for calculation of sheet size.)


Where does the sheet go?

On the liver, in the abdominal viscera or under the skin. In dog experiments the most promising place is on the omentum.


How long will the implant function?

It should function for years, and if its function declines it can be retrieved and replaced or a "booster" sheet can be added.


Where will the islets come from?

Initially from humans; human islets work, but availability is limited. Later sheets can be made with islets from animals (most likely pigs) or from cell culture of human or genetically engineered islets. Islet cell culture may be an excellent long-term source of islets. However, such technology is many years from being proven.


How much could Islet Sheet Medical charge for a bio-artificial pancreas?

The direct cost of diabetes is an average of $7,000 per diabetic per year; for juvenile diabetes, the average is more than $14,000. (This does not include loss of life and reduced quality of life.) Thus an implant that worked for several years could be priced at tens of thousands of dollars.


Will Islet Sheets help both juvenile diabetics and adult diabetics?

The Islet Sheet can help everyone with juvenile diabetes and those adult diabetics that have developed insulin insufficiency and must inject insulin. These two groups total 1.4 million in the United States.


How can I participate in clinical studies?

We are often asked by diabetics how they can sign up to get an implant. You are welcome to e-mail us, we keep a list; but the plain fact is that our initial trials will be done at a medical research center, and recruitment for such studies is traditionally handled by the doctors performing the study. Thus ISM will not have much influence on the selection of volunteers for implantation. Recruitment for clinical studies will not begin until animal studies are further along.


When will clinical studies begin?

This is highly dependent on our progress. Our current projection is June, 2001 (click here). It is also possible that animal studies will reveal a problem with the sheet that we cannot solve.


When will the Islet Sheet be available?

This is highly dependent on our progress. Our current projection is June, 2003 (click here).


Additional questions?

Please feel free to contact the Islet Medical Team.