this post was submitted on 20 Dec 2023
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We can genetically engineer bacteria to mimic the missing pancreatic cells, and it's not too different to the way most insulin is produced as all that's new is the system to stop producing insulin when blood sugars are already low enough. However, if you put them in a person, the immune system attacks the bacteria, so they need isolating. To do that, we need a membrane that lets sugar in and insulin out, but doesn't let antigens or live bacteria out, and doesn't let immune cells in. Even if the bacteria are held in place, if immune cells can get in, it's no better than a pancreatic transplant as you'll still need immunosuppressants, and they're generally worse than dealing with type one manually. Development of the membrane keeps hitting unexpected hurdles, so artifical pancreases are still unable to start trials, and then they might take a decade.
There are other approaches, e.g. using electronics to control photosensitive insulin producing bacteria, but they don't have any advantages (the membrane still has to let sugar in so the bacteria can eat) and have more things that can go wrong.
In theory, and this is another couple of major advancements of this tech away, if you can teach the body to stop attacking specific cells you can do a transplant without rejection. Teach the body to not attack the new pancreas, then stick it in there.
This should be possible with this tech, though it would require a mature and advanced process compared to what we have now. Genetic chimeras can exist without the immune system going crazy, presumably because it recognizes all those parts as "part of the body". If it can be taught to recognize other implanted material as acceptable that opens up a huge range of options. Even a lifetime of immune system training therapy is better than a lifetime of immunosuppressants.
Ultimately what they need to do is decipher stem cell development and fetal development and use the patient's own cells to replace the lost islet cells.
If you don't have a solution to the autoimmune aspect, then a stem-cell-based treatment is no better than one with engineered bacteria or someone else's cells. The originals are gone because the body mistakenly thought they were foreign. A treatment like the article discusses might make stem cells more viable than the alternatives, though, as they'd be less foreign, so need less immune system alteration.