Figure 4.

Organ-on-a-chip examples. A: Schematic shows the design of a human gut-on-a-chip. Human intestinal epithelial cells are cultured on an ECM-coated porous membrane and exposed to low levels of fluid shear stress. Side vacuum chambers are used to apply cyclic strain that mimics physiological peristaltic motions. Reproduced from Kim et al.⁹⁰ with permission from The Royal Society of Chemistry. B: Schematics show the design of the liver-on-a-chip. Hepatocytes are cultured in a central channel, surrounded by small, closely spaced parallel channels that mimic the endothelial cell barrier. Two side channels deliver nutrients and drugs by diffusive to the central cell culture region. Reproduced from Lee et al.²³ with permission from Wiley Periodicals. Copyright 2007, Wiley Periodicals, Inc. C: A human lung-on-a-chip models the alveolar-capillary interface. Alveolar epithelial cells and pulmonary microvascular endothelial cells are cultured on opposite sides of a PDMS membrane. Vacuum is applied to lateral side chambers to stretch the PDMS membrane and mimic physiological breathing. From Hung et al.⁹¹ Reprinted with permission from AAAS.D: Schematics show the design of a kidney duct model. Renal cells are cultured within the channel and exposed to fluid shear stress, osmotic gradients, and hormonal stimulation. Reproduced from Jang et al.⁹² with permission from The Royal Society of Chemistry.