Islet Transplantation Using Implantable Microreactors

The overall objective of this research program is to develop implantable microreactors containingislets for treatment of diabetic patients. We will focus on development of technology required tofabricate these microreactors, and on in vitro studies of islet viability and function. These sphericalmicroreactors will consist of a core which contains the islets, surrounded by a permselective shell. Thispermselective coating permits crossover of low molecular weight substances, including nutrients,electrolytes, oxygen and bioactive secretory products such as insulin, but not of immunocytes and othertransplant rejection effector mechanisms. These microreactors are of sufficiently small diameter thatthey can be injected subcutaneously, intraperitoneally or in other sites simply by using a hypodermicsyringe and needle. This approach does not require lifelong regimen of immunosuppressive drugs withserious side effects. In addition, it does not require costly and complicated surgery, and offers a solutionto the presently insurmountable problem of procuring sufficient numbers of human pancreatic organs bypermitting xenografting of islets from animal sources.