Lots of organizations are working on new ways to accomplish islet cell transplantation in which the immune system does not kill off the transplanted cells. If they could do that, we'd likely have a cure for diabetes. But it ain't easy, especially because we're talking about transplanting into people whose immune systems are in mega-attack mode to begin with (type 1 diabetics).
The Diabetes Research Institute (DRI) in Florida is currently working on this challenge in an especially intriguing way. Borrowing a concept called "stealth tolerance" from cancer research, they've looked at areas in the body where the immune system seems to be less aggressive, i.e. an "immune safe" area. One of those happens to be male genitalia (ewww — dismissed!) The other happens to be inside the eye. The stealth approach does away with the need for the "cocktail of immuno-suppressants" that's usually required, and that causes the patient's body so much trouble.
The DRI's researchers are using the anterior chamber of the eye as a spot to implant islet cells, derived from adult stem cells. So far they've found the transplants do indeed reduce the amount of insulin needed in animals. Of course they still need to "encapsulate" these cells to protect them when implanted.
"Encapsulation is not new, but the coating was too thick in the past," DRI Chief Operating Officer, Dr. Mitra Zehtab, explained at a recent research update held at a private home in Northern California (just a few miles from my house!). "We've developed new ultra-thin material for encapsulation — it's miniscule thinness — that coats the islets to protect them. It works like slow release capsules."
Dr. Zehtab further explained that researchers are trying to put these coated capsules into small "biohybrid devices" like a tiny mesh cylinder that houses and protects transplanted cells. (See our previous coverage of these "reverse IUD devices" here.)
Because the eye affords a new, clear way to directly view and monitor how transplanted insulin-producing cells function after they're infused into a patient, the approach is called the "Living Window." DRI researcher Per-Olof Berggren also presented about progress on it at the ADA Conference last week. Th