I can't help but wonder why they can't take a batch of E. coli engineered to produce insulin from blood glucose and place them inside the chamber of an electronic implant that monitors the glucose levels then "feeds" the E. coli when the number reaches a certain level and releases the resulting insulin. There'd be a minimum "always on" state for the E. coli but if the pancreas in question has failed that would be needed anyway.

I don't know, maybe the technology just isn't there yet, but it seems like something like this should be repairable. Instead it's drugs or a transplant. :-(