Artificial Pancreatic Tissue Could Help Control Diabetes

The ECM was formed by removing cells from pancreatic tissue with biological detergents, so that only the proteins that bind the cells together were left. The resulting matrix was seeded with donor islet cells and supportive stem cells, and the entire construct was successfully transplanted and maintained in a recipient animal model using microsurgical techniques.

The ECM not only helps to understand the microarchitecture of the pancreas, but also prolongs the survival and preserves the function of the islets. The researchers found that the pancreatic islets survived longer in the bioartificial matrix than in conventional transplantation sites, and that they produced significantly more insulin when challenged with glucose. The proof-of-concept study of the ECM scaffold was presented at the annual clinical congress of the American College of Surgeons (ACS), held during October 2010, in Washington D.C., (USA).

"By default, the survival and function of the islet cells will always be worse in any organ other than the pancreas,” said lead investigator Claudius Conrad, M.D., Ph.D., chief resident in surgery at MGH. "To engineer an endocrine pancreas, islet- and stem cells require an extracellular matrix that provides specific architecture, microstructure, and most importantly microvasculature to form the islet cell specific niche.”

"Islet cell transplantation is the only treatment of insulin dependent diabetes that can consistently establish insulin independence,” added Dr. Conrad. "However, islets only feel at home in the pancreatic niche, and therefore their survival and ability to produce insulin declines rapidly if transplanted, for example, in the liver.”

The islets of Langerhans are the regions of the pancreas that contain its endocrine cells, constituting approximately 1 to 2% of the mass of the pancreas. There are about one million islets in a healthy adult human pancreas, which are distributed throughout the organ, with a combined mass of 1 g - 1.5 g. Hormones produced in the islets of Langerhans are secreted directly into the blood flow by at least five different types of cells; Alpha cells produce glucagon (15% - 20% of total islet cells); Beta cells produce insulin and amylin (65% - 80%); Delta cells produce somatostatin (3% - 10%); PP cells produce pancreatic polypeptide (3% - 5%); and Epsilon cells produce ghrelin (less than 1%).

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