A cure for Type 1 diabetes has been possible by whole pancreas or islet cell transplantation for a number of years. The success of transplants has improved significantly over recent years. Transplants, however, are extremely limited by the lack of donor pancreas material and are offered in only a very small minority of patients even in those who have developed severe complications such as hypoglycaemic unawareness.

Although an additional problem with pancreas transplants has concerned the need for long-term anti-rejection drugs, it is the fact that Type 1 diabetes is an autoimmune disease that has hampered success in this area. This translates into the knowledge that it was the patient’s own immune system which proved to be responsible for the malfunctioning pancreas cells in the first place. This destructive process continues to cause harm to any newly transplanted cells unless measures are taken to protect them.

There have been a variety of interesting scientific approaches to solving these problems and therefore finding a stem cell therapy cure for Type 1 diabetes.

• One idea has been to take skin tissue from individual patients with diabetes, induce pleuripotent stem cells from these cells and then to create a supply of functioning beta cells from the stem cells. This idea has been tested in animal models in the laboratory. The technique could if successful in humans provide an individual patient with a supply of their own genetically compatible transplantable pancreatic islet cells eliminating the requirement for anti-rejection drugs. Unfortunately there is a long way to go before this optimism fulfils its clinical potential.
  
  Of paramount importance is safety, further studies will require a detailed analysis of these issues relating to genetically engineered material. Will it be stable or could unexpected tumours derive from the changes in cell biology? Also the supply of transplantable material may not be the self limiting problem, what about the immune attack of pancreatic cells which may still be going on in these patients. How will we be able to induce immune tolerance and protect the new beta cells?


• A second and very interesting further stem cell approach to curing diabetes involves protecting stem cells from immune attack by developing them within a transplantable encapsulated device. Human embryonic stem cells can be matured into functioning pancreatic beta cells within an encapsulated membrane. This can then be placed in the subcutaneous tissue of the patients with the aim of providing the source of insulin production previously lost during the development of diabetes. Experiments have already been successfully tested in mice. Results proved this system to offer the necessary immunoprotection and proved that these devices can be stable, biocompatible, non degradable in addition to offering the cells an environment to thrive and secrete insulin. The next stage is to get it working in humans but there are safety issues here too. Again there are concerns regarding genetically engineered cells and the purity of the solutions used to sustain them before transplantation.