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Signal Breakthrough: Islet Sheets Thrive in Pigs

November 26th, 2012

At the Islet Sheet Project we have entered a new era — the era of large-animal efficacy results. This is the most important and perilous step on the path from thin-sheet concept to clinical product. Experiments are expensive, and a few failures could mean the end of the project.

I am happy to report a most exciting breakthrough: we have demonstrated that Islet Sheets implanted in diabetic pigs keep islets alive and producing insulin for months. This is the most important accomplishment to date, because getting islets to thrive in the first few months is the most difficult milestone. Encapsulation devices fail when the encapsulated islets die, and islets can die for many reasons. The current study shows that the Islet Sheet prevents allograft immune rejection. It also shows that the vascularized membrane that grows around the sheet provides sufficient nutrients to keep the islets alive — and indeed islets are making, storing, and secreting insulin. We estimate that at 65 days >90% of the islets were functional because they stained for insulin with dithizone dye (see figure); only functional islets are stained by dithizone.

Pig islets (dithizone pink) in Islet Sheet, retrieved after 65 days in diabetic pig, are alive and making insulin.

In the pigs studied, the need for external insulin was reduced but not completely eliminated, so it appears that the islets were not performing to their full potential. Our initial analysis of these recent results suggests several ways to increase islet function in this model. We are performing additional studies to investigate these. Our team predicts that, since the islets are functional, increasing their functionality is likely. We believe we will be able to completely control a pig’s diabetes with insulin made by the Islet Sheets.

The pig was not our first choice of for a large-animal model, but it was a logical first step because pig islets and diabetic pigs were available at the laboratory of our collaborator Jonathan Lakey. It turns out that there are good reasons why the pig is not a common model for T1D. Pigs are ornery: they resist insulin administration and try to shed CGM sensors, so it is difficult to control their BGs with insulin. And we found that some features of their peritoneal implant response appear to differ from those of dogs and humans.

We would like to expand our studies with two species of diabetic large animals, dogs and nonhuman primates. These are well-established models. A leading diabetes researcher with an established primate diabetes model is eager to begin collaborating with us. We hope we can find resources for this work in 2013.

With more pigs scheduled for Islet Sheet implants in January, and with canine and monkey studies in development, our projected expense for research is growing fast.  The Islet Sheet is potentially a functional cure for T1D (using the JDCA definition). Hanuman Medical Foundation (the sponsor of this site) is the only foundation currently supporting the Islet Sheet project. Other diabetes charities have expressed, at most, mild interest in the Islet Sheet Project, even though some have provided massive funding for another project that has not even selected an encapsulation method to study and thus is many years behind the Islet Sheet.  I don’t think this is the best way to a cure.

If you contribute to any of these charities, I urge you to become educated about cure research and understand how your donations are being used. The T1D charities raise money by telling parents of newly diagnosed diabetic children that they are working for a cure. As I have long believed, and the JDCA has now documented, this is not true; a declining minority of funds is used for research toward a practical cure. The Islet Sheet is a practical cure and is now in the midst of crucial studies that will prove — or disprove — its utility in the coming months.

It is time for donors committed to a cure for type 1 diabetes to hold accountable the charities they fund. I urge you to direct at least some of what you plan to donate to Hanuman Medical Foundation. You will know where your money is going, and you’ll be informed of the result. If the result is good, we will be much closer to a cure.

 

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11 Responses to “Signal Breakthrough: Islet Sheets Thrive in Pigs”

  1. Scott – congrats to you and the team on this. This is great news.

  2. Paul Edwards says:

    Many thanks to Scott for keeping me informed on progress. This is very exciting news and I hope that the experiments continue to go to plan. I have been following Islet Sheet development for many years now and believe it to have tremendous potential. As far as I know we have nothing like this going on in the UK and I pray that success finally does come and sooner, rather than later! I must say that I am disappointed to hear of the funding difficulties. My family has donated quite a lot of money, on a regular basis, in the UK. I will try to investigate where our money goes and would appreciate and further information about this if you are able to make it available please.

  3. Paul Edwards says:

    Thanks very much for your prompt reply Scott. I’ve very quickly read through the JDCA Funding Report (I’ll read it thoroughly later)and it makes for very disappointing reading! As a donor I am worried that contributions we have made to Diabetes UK may not be used as we would wish and I will make an effort to check up on this. I remember you telling me of Prof. Paul Johnson’s work and I’ll certainly keep an eye on what he is doing. Best wishes to you and keep up the good work, Paul

  4. Carol A Schneider PhD JD says:

    Congratulations! It’s a long haul but it looks like you are making progresss. There is an ever expanding need for treatments for diabetes, so the funding may be a matter of finding the right people who will recognize the benefits of your methods.

  5. Frank Czerwinski says:

    Scott:
    I am greatful of your continued success. (Please keep us posted on the islet.org board.) Especially in light of the challenges presented in the JDCA report referenced above. I’ve long suspected all the points from that paper. That information needs to be in the hands of every parent of a child with Type 1 Diabetes along with specific actions that we can take to collectively move us to accountability of donor dollar spending. Especially for JDRF.
    Frank Cz.

  6. Brian Braxton says:

    I am very excited about this work and the progress. But the sad reality is not enough parents(people) are asking for transparency from the organizations they fund. I believe if more money was sent to fund cure options such as encapsulation we would know sooner rather then later if this would be a cure. Unfortunately the vast majority of the funding goes to treatment options, which I am all for, but people should be given a choice as to how they want their money spent. I want my funding to go towards a cure. Mr. King thanks for the updates.

  7. Scriabin says:

    Congratulations on this major achievement!
    We can start dreaming about a commercial availability of the Islet Sheet. ;)
    Equally interesting is the question of the durability of the islets. Can they survive even for years in this environment? The future will tell…

  8. Therese B. says:

    So good to see you are still trying! Encouraging to see anyone truly trying for the sake of a cure and not just a paycheck.

    Therese

  9. Nicolas says:

    Just wanted to drop in and say, thanks for trying to find a cure for me. You already make my life better by just trying.

  10. Scott King says:

    Nicolas-
    Thanks.
    As you can see from the editor’s post, I am taking some time off for family. But you should know that we are reviewing the mini-pig data with advice of our science advisory board to determine the best experiments to move forward. Scott King

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