Characterization of nanoporous membranes for immunoisolation: Diffusion properties and tissue effects

Through its ability to achieve highly controled micro-architectures on size scale relevant to living systems, microfabrication technology offers unique opportunities to more precisely engineer biocapsules that allow free exchange of nutrients, waste products, and secreted therapeutic proteins but exclude the passage of lymphocytes and antibodies responsible for the onset of the foreign body response. In this study, diffusion of biologically relevant molecules through the microfabricated membrane was characterized using a two-compartment diffusion chamber. In order to improve in vivo long term diffusion performance, biocapsules were implanted in animals and the degree of foreign body response was assessed.