Encapsulated Islets—Different Techniques Being Studied
The goal of all islet encapsulation research is to prevent the need for immunosuppressive drugs. These drugs prevent the immune system from attacking the new islet cells but cause serious complications of their own. Encapsulation technology involves enclosing insulin-producing islet cells in a semi-permeable membrane that allows small molecules, like glucose, insulin, and nutrients to pass but prevents larger immune-system molecules from entering.
There are three types of encapsulation being studied-microcapsules, diffusion chambers, and perfusion devices. A report written by the Department of Surgery at Deaconess Hospital in Boston and published in Clinical Pharmacokinetics, June 1995, detailed the efficacy of each method.
"Microcapsules injected into the abdominal cavity in a large quantity achieved glycaemic control, but required a small amount of immunosuppression to prevent fibrosis around the capsules."
Diffusion chambers placed in the abdomen of diabetic dogs resulted in "excellent glycaemic control without immunosuppression...However, their use was limited by the eventual breakage of tubular chambers."
"Long term control of severe diabetes mellitus was achieved in totally pancreatectomised dogs without immunosuppression by devices seeded with [dog and pig] islets. [If developed successfully], the vascularised artificial pancreas could be an excellent alternative to DCCT-type intensive insulin therapy or pancreatic transplantation."Click Here To View Or Post Comments