Development of a computational fluid dynamics model describing transport phenomena in conformal encapsulated ancreatic islets for the optimization of polymeric coating features

Various techniques for diabetes care have been developed through the years, especially targeted to type 1 diabetes, ranging from conventional medical therapies to whole organ or pancreatic islets transplantation. Thanks to technological advance in the bioengineering research area and continuous progresses in biomaterials technology, the development of immunoisolation systems to transplant islet cells has been recently adopted: the aim of these systems is to protect the transplanted islets through a physical barrier interposed between the transplanted cells and the immune system of the recipient. The main advantages associated with this approach are the elimination of immunosuppressive drug therapy and the opportunity, if the isolation works properly, to not use only allogeneic islet cells but also cells coming from xenogeneic source to compensate for the shortage of human pancreas availability. A novel method of encapsulation is under development at the Diabetes Research Institute of Miami, aimed to allow a conformal (i.e. uniform) coating of the islets, thus minimizing capsule thickness (10-20 μm), size and graft volume. The present thesis is focused on this innovative method of islet encapsulation, aiming to characterize the effect that polymeric coating has on the glucose-induced insulin response of pancreatic islets since the transport phenomena involved are influenced by the diffusion properties of the polymeric material of which the coating is made of. To this aim, numerical modeling is a useful tool to study the transport phenomena occurring in encapsulated pancreatic islets, developing a model that describe their dynamics through the conformal coating under in vivo-like glucose stimulation conditions. The model was developed at the Laboratory of Computational Biomechanics (LCB) of the Department of Electronics, Information and Bioengineering (DEIB) of Politecnico di Milano in collaboration with the Diabetes Research Institute (DRI), University of Miami, Miller School of Medicine.