Conformal polymer coatings for pancreatic islets transplantation.

The aim of this work was to improve an aqueous two-phase system methodology for fabrication of coherent microcapsules. Simulated microgravity was investigated as tool to improve the cell cluster morphology in order to increase the overall quality of conformal polymer coatings, while the application of two concentric alginate layers and the use of barium instead of calcium as gelling ion was evaluated. Simulated microgravity enabled improvement of neonatal porcine cell cluster sphericity however the freely floating cells, originated during incubation and often found on the capsule surface, raised immunological concerns. Overall, these technical changes translated into improving quality of microcapsules, in terms of either morphologic aspects or the membrane's functional performance. Preparation procedure did not seem to adversely affect viability of the embodied cells. Moreover, the employed alginates high biocompatibility, per se, would promote a good encapsulated cell engraftment. Minimization of last generation microcapsule's size, made of highly purified alginates, represents a further advance on the new horizons of cell therapy for the treatment of a wide variety of chronic disorders, including insulin-dependent diabetes mellitus.