Diabetes and its complications have a significant impact on both individuals with the disease, and on society overall, with annual direct and indirect costs exceeding 90 billion dollars (www.who.int). More than 220 million people worldwide are affected by diabetes and it is estimated that its incidence might increase 3-4% per year. Among this population, the patients who have lost all insulin secretion capacity, and therefore who need insulin supply for life, represent the group with the highest need for human and funding healthcare support due to the combined complexity and cost of the therapy. The frequent lack of diabetes control in these cases leads to a high occurrence of acute and long-term complications, which constitute a heavy burden at the individual, family and society levels.
Currently, there is no available treatment able to continuously normalize blood glucose levels and to prevent acute and late complications in these patients. Significant improvements have been achieved through the development of insulin analogues and insulin delivery devices that allow better control of diabetes. However, the need for patients to be involvemed daily in their care management, combined with the significant additional costs associated with these innovations, prevent their wider application. Whole pancreas and islet transplantation have both been shown to result in near-to-normal diabetes control with reduced patient input. However, the lack of available donor pancreases, combined with the need for life-long costly immunosuppression with their associated deleterious side-effects, mean that these treatments currently are only available for the most severe adult patients.
Therefore, in comparison to the currently available therapies for Type 1 diabetes, the development of a bioartificial pancreas is expected to have numerous potential advantages and impacts, and thereby improve the quality of life of many people having Type 1 diabetes:
The strategy of encapsulation involves placing insulin-secretory cells within semi-permeable devices made of friendly and biocompatible materials. This kind of device should allow the passage of small molecules such as insulin and glucose but prevent the entry of molecules of the immune system that could kill the encapslated cells. Thus, encapsulating these cells should prevent allograft rejection and autoimmune reaction.