Microencapsulation and tissue engineering as an alternative treatment of diabetes

In the 70's, pancreatic islet transplantation arose as an attractive altern ative to restore normoglycemia; however, the scarcity of donors and difficu lties with allotransplants, even under immunosuppressive treatment, greatly hampered the use of this alternative. Several materials and devices have b een developed to circumvent the problem of islet rejection by the recipient , but, so far, none has proved to be totally effective. A major barrier to transpose is the highly organized islet architecture and its physical and c hemical setting in the pancreatic parenchyma. In order to tackle this probl em, we assembled a multidisciplinary team that has been working towards set ting up the Human Pancreatic Islets Unit at the Chemistry Institute of the University of S (a) over tildeo Paulo, to collect and process pancreas from human donors, upon consent, in order to produce purified, viable and funct ional islets to be used in transplants. Collaboration with the private ente rprise has allowed access to the latest developed biomaterials for islet en capsulation and immunoisolation. Reasoning that the natural islet microenvi ronment should be mimicked for optimum viability and function, we set out t o isolate extracellular matrix components from human pancreas, not only for analytical purposes, but also to be used as supplementary components of en capsulating materials. A protocol was designed to routinely culture differe nt pancreatic tissues (islets, parenchyma and ducts) in the presence of sev eral pancreatic extracellular matrix components and peptide growth factors to enrich the beta cell population in vitro before transplantation into pat ients. In addition to representing a therapeutic promise, this initiative i s an example of productive partnership between the medical and scientific s ectors of the university and private enterprises.