There is also what Sigilon (now Eli Lilly) is doing, which is to encapsulate living cells in a matrix they cannot escape. The cells sense glucose levels and sec

There is also what Sigilon (now Eli Lilly) is doing, which is to encapsulate living cells in a matrix they cannot escape. The cells sense glucose levels and secrete appropriate levels of insulin locally. In the current iteration I think the millimeter sized beads are injected in the peritoneum, and are removable.