Why cant you implant endocrine cells to produce insulin?

I was diagnosed with type 1 diabetes about 3 days ago and I started thinking about why there isn't a cure, probably a common idea among most new diabetics. But why isn't it possible to implant new endocrine cells (or pancreatic islets, alpha and beta cells, or whatever) in a pancreas to have it start to produce insulin on its own again? I'm not trying to be a hero or anything i just want a real answer to this question so i can stop thinking about it :)