Insulin producing cell transplants

In Type-I diabetes, which is due to the loss of insulin-producing cells as a consequence of autoimmune disorders, substitution of insulin is the most important measure. However, merely to inject one daily dose is not an adequate therapy. Here, the objective is to mimic the daily variations in plasma insulin which are closely related to food intake. One such attempt which has improved microvascular complications is intensified insulino-therapy through multiple daily injections of insulin. Another approach is to develop techniques of islet transplantation and using a bioartificial pancreas. In the case of islet transplantation, tissues will not only respond to changes in blood glucose levels but also to hormones of the entero-insular axis. 

Lee SH, Hao E, Savinov AY, Geron 1, Strongin AY, Itkin-Ansari P. 2009. Human beta-cell precursors mature into functional insulin-producing cells in an immunoisolation device Implications for diabetes cell therapies. Transplantation 87(7) 983-91. 

Although infusion pumps can go some way towards mimicking normal control of blood insulin levels, transplantation of insulin-producing pancreatic cells should effectively cure the diabetic patient, and research aimed at underpinning this approach continues. 

Initial experiments in the 1970s using inbred strains of rats illustrated the feasibility of this approach. Insulin-producing pancreatic islet cells donated by one set of rats were transplanted into other rats of the same strain, first made diabetic by injection with drugs such as streptozotocin, which destroy the pancreatic B cells. 

The ability to transfer genes into islets and perhaps the insulin producing fl cells appears to represent an excellent opportunity to utilize gene therapy for improving the clinical efficacy of islet cell transplantation. Unlike the case of other organ transplants... 

Transplantation A possible way of dealing with diabetes would be to transplant cells or the complete organ that produces insulin in the body. 

Fig. 5 shows microencapsulated mice islets intended for intraportal (liver) transplantation to achieve clinical normoglycemia. The islet s p-cells produce insulin in response to a blood glucose stimulus providing a therapeutic alternative to daily insulin injections. The capsule size is optimized to permit oxygen diffusion ... 

Transplanting foreign cells into a body is a method proposed to compensate for the failure of native cells to produce essential biochemicals. Type I diabetics, for instance, lose the ability to produce sufficient amounts of insulin. 

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