In vivo testing of the intravascular bioartificial pancreas device (iBAP) with 10% islet density encapsulated with 10 nm-pore size SNM under either diffusion or convection for 3 days. (a) An image of the explanted iBAP with diffusion (back) and convection (front) of the device (i). An SEM image of the diffusion-side implanted membrane showed a patent surface (ii, top) (scale bar = 100 μm) and an SEM image of the convection-side membrane presented coverage of proteins and cells on the surface (ii) (scale bar = 10 μm). (b) Immunofluorescence staining of platelet adhesion CD41 marker (green) and platelet activation CD62p marker (red). The rectangular pore-containing regions surrounded by solid silicon regions were shown in the bright field image for diffusion-side membrane (i) and convection-side membrane (iii). The platelet adhesion (green) was minimal on the diffusion-side membrane (ii), whereas more platelet adhesion (green) and activation (red) was detected on the convection-side membrane (iv) (scale bar = 20 μm). (c) The SNM-encapsulated iBAP with 10% islet density under convection both in vitro (in vitro 10% convection) and in vivo (in vivo 10% convection) showed higher cell viability compared to that under diffusion in vitro (in vitro 10% diffusion) and in vivo (in vivo 10% diffusion). (n > 3, *p < 0.05). The in vitro negative control was those islets that were assembled in the iBAP with no medium circulation for 3 days. Viabilities of islets that were immediately encapsulated in agarose and dispensed into the islet chamber (IC) without further testing were evaluated as the in vitro positive control. (d) Viable (green) and dead (red) cells were stained for in vitro positive control (i), in vitro negative control (ii), in vitro 10% islet density under diffusion (iii), in vitro 10% islet density under convection (iv), in vivo 10% islet density under diffusion (v), in vivo 10% islet density under convection (vi) (scale bar = 50 μm). The SNM-encapsulated iBAP with 10% islet density under convection in vivo (vi) showed similar viability to the in vitro positive control.