Figure 8. Intravascular mass transport and kidney reabsorption.

A) Schematic of intervascular mass transport in the intestine. b) Schematic of intervascular mass transport in the lung. C) Schematic of intervascular mass transport in the nephron. d) A biomimetic nephron constructed in a monolithic hydrogel vessel chip. Two channels, lined by Madin-Darby canine kidney cells (MDCKs) and HUVECs, represented the tubule and vessel, respectively. Two fluorescent dyes, CellTraker red and green, were perfused into one channel and allowed to diffuse into the other channel. White dash boxes indicate hydrogel located between two channels. Reproduced with permission.^[42] Copyright 2013, Royal Society of Chemistry. e) Cellularized tubules (in purple) and vessels (in green) were constructed in collagen hydrogels, mechanically supported by polymer scaffolds. f) Albumin-reabsorption in the tubule, compared with inulin and decellularized devices. e-f) Reproduced with permission. ^[293] Copyright 2018, John Wiley and Sons. g) PTECs and glomerular microvascular ECs (GMECs) for confluent monolayers in hydrogel channels to mimic renal tubules and vessels. Scale bar, 100 μm. h) Schematic and quantitative glucose-reabsorption in the 3D hydrogel channel, compared to two 2D models. G-h) Reproduced with permission.^[137] Copyright 2019, Creative Commons Attribution license.