Encapsulating Islets: Big Hope in Small Packages

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A recent paper published in Nature by a team of researchers that included scientists from the Massachusetts Institute of Technology (MIT) and Joslin’s Dr. Gordon Weir announced the successful testing of a new material (modified alginates) intended to protect newly transplanted beta cells from the type 1 autoimmune attack. This material could prove to be the key to encapsulating implanted beta cells which could release insulin and, at the same time, not induce immune responses from the host.

The following article (originally posted in 2013) explains how they did it.

Gordon Weir, M.D., Co-Head of the Section on Islet Cell and Regenerative Biology at Joslin Diabetes Center, has teamed up with MIT researchers Robert Langer, Ph.D., Institute Professor, and Daniel Anderson, Ph.D., Associate Professor, to move the type 1 diabetes field one step closer to a cure. The four-year old collaboration tackles the problem of protecting transplanted beta cells (the islet cells that secrete insulin) from continued autoimmune attack.

The beta cells of people with type 1 diabetes are almost entirely destroyed by the immune system, which means these individuals produce little to no insulin. Attempts to replace the failing beta cells are met with the same autoimmunity that caused the problem in the first place, with the added difficulty of transplant rejection (when another part of the immune system attacks the donor cells).

A technique called encapsulation seemed like a way around this problem. Take an islet cell, wrap it in protective material, and it will be safe from the autoimmune onslaught.

Coating islets has proved fairly easy; they can be coated with a seaweed-derived gel called alginate. The islet/alginate liquid mixture falls as droplets into a salt bath which binds strands of alginate together into a tightly woven mesh around the islet. The weave is loose enough that insulin can get out and the nutrients the cell needs to survive can get in, but tight enough that the autoimmune T-cells aiming to destroy the beta cells can’t get through.

While encapsulation prevents T-cells from getting to the islets, there may still be problems because the immune system can sometimes recognize the capsules as a foreign invader. This perceived threat is met by layering scar tissue around the capsules, thus preventing oxygen and other nutrients from getting to the beta cells.

Alginate encapsulating beta cells; Credit: Weir Lab Joslin Diabetes Center

Researchers realized they needed to somehow trick the immune system into thinking the capsules were part of the body’s biology. So the JDRF approached Dr. Langer, an expert in biomaterials, about creating a new type of alginate that would fix the problem.

The labs of Dr. Langer and Dr. Anderson started modifying the existing alginate to see what properties they could add that would make it more invisible to the immune system. They brought Dr. Weir and his Joslin lab on board to consult on the process and the biology.

The MIT labs use robots to make hundreds of new versions of the alginate with different potentially biocompatible properties.

They’ve been adding some extra features, as well. While the alginate is more biocompatible than before, it’s not a perfect match to the transplant recipient, so the capsules still stimulate some immune response.  The MIT labs embed into the capsule an anti-inflammation drug that is slowly released throughout the first seven days of the transplant—the post-implant period with the most active immune response.

But some anti-inflammatory drugs may interfere with the secretion of insulin. To avoid this step backwards, the scientists are working to create two layers within the capsule. The first houses the insulin-secreting beta cells. The second releases the anti-inflammatory drugs, so the drugs and beta cells never come in contact.

When the researchers come up with a combination of properties that could work, they encapsulate islets in the new material and test it in a mouse model of type 1 diabetes.

This collaboration among MIT, Joslin, and JDRF has already yielded positive results in rodents. The next step is to try the successful alginates in larger animals to see if the capsules can withstand more robust immune systems.

While encapsulated islets wouldn’t be a complete cure—that would require something to also halt the body’s autoimmunity to beta cells—it would allow beta cells to act naturally, freeing people with type 1 diabetes from multiple daily injections, untethering them from pumps, and ending glucose testing.

15 Responses to Encapsulating Islets: Big Hope in Small Packages

  1. Jacquelyn Dieckman says:

    WOW!!! I’m excited about this news! Thank you SO much to all the scientists involved. I’m a 56-year veteran of Type 1, so I’d love something like this, but these discoveries could be especially beneficial to children. Way to Go!

  2. Birgitta Rice says:

    Such exciting possibilities in this article!

    Is the b-cell destruction continuous through-out at diabetic’s life?

    I believe I have had some beta cell regeneration ( I am part of the 50 year Medalist study). Do these new beta-cells also succumb to destruction, or are they a new breed that can survive? Another point to think about.

  3. Mark Rosenbaum says:

    Fascinating information about the closest thing to a cure. I”m a 56 year diabetic, since age 6, and part of the medalist study group. Would encapsulation and the resulting normalization of BG levels help to alleviate all or some of the complications associated with diabetes?

  4. Bruce Comen says:

    When will the human trails begin? I’m a type 1 68 year old male and would love to participate.


  5. Edward Certusi Joslin Clinic # 060128 says:

    I have been a type 1 diabetic for 54 years with only one complication
    gastroparesis. I am interested in the drug trial. Edward Certusi

  6. Charles E. Turner Jr. says:

    I am a 50 Year Medalists and have been a type 1 diabetic for 61 years. I don’t have any health problems. I take 46 units of Novilin N in the AM and 4 units in the PM and Novilin R as required. My HbA1c runs between 6.4 to 6.6.
    What I have read about in this report gives me something to look forward to. I am 84 years old and it would make growing older easier.

  7. Ann Hoffman says:

    Love to hear this. We are hoping my husband will not have to spend thousands on pumps and supplies and feel better! So grateful for the informatiom

  8. Mari C Sullivan,MSN, ARNP says:

    Sign me up! I will HAPPILY take place in even a phase 1 clincial trial. I have T1D x 30 years and zero complications but worry that the occassional high BG is feeding my breast cancer! So I am up for a better way to manage this DM. SIGN ME UP PLEASE! You have my email address now.

  9. Harold Walker says:

    I ‘m so glad to get some news about type one research; most of the news is all about type two. My years with type one have brought me too close to death too many times. When I was first educated about my Diabetes I was told: It’s all about diet, Insulin, and exercise. Keep these in balance or you will DIE! I am glad things have come so far today; but so much more is necessary to live a comfortable life as a type One Diabetic Thank you for your research.

  10. Nidia morisset says:

    It sounds great, but what happens to diabetes mellitus patients who are allergic to fish and seafood. Would they be allergic to this capsule?

  11. Linda Lingo says:

    This is great news. I am part of the 50 year medalists study. I am 69 years old and have had Type I diabetes for 65 years. I have some of the complications with my eyes, and a painful mononeuropaty in my leg. I was involved in some of the studies as a clinical diabetes nurse in the 1980s and 1990s, but am retired now. I, also, would like to participate in any humane trials also. I would like to not have to worry that I will possibly not wake up ever some night due to hypoglycemia.

  12. John Suurhans says:

    Sounds like great news. How far off are you thinking? I would be interested in participating but would want to know the possible side affects? I can’t think of any better institutions like Joslin & MIT working towards a cure. I’m 46, go to the gym, T1 since I was 26, no complications.

  13. Carolyn Stitson says:

    This is most encouraging news! I will have had T1 for 51 years next month, and am more than willing to join any studies/trials for the encapsulation project. In addition, having worked at MIT for 47 years (retired in November 2014), I recognize Dr. Langer, know of his work and have spoken with him and his admin over the years, having worked as an admin for one of his senior colleagues.
    How do I go about volunteering for this study?

  14. margarita de torres says:

    volunteer for human trials
    already a joslin pacient

  15. Robert Connors says:

    This is a great study and development I would love to be involved if it was possible I’m 50 and had diabetes for 16 years .

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