Figure 1
From: In vitro metabolic zonation through oxygen gradient on a chip
Microfluidic chip design and oxygen gradient validation. (A) Representative image of the liver zonation generated across the hepatic lobules. Hepatocytes are naturally exposed to an oxygen gradient according to their position along the portal-central axis that allows distinguishing “periportal” from “perivenous” hepatocytes. Schematic representation of miniaturization process of the sinusoid geometry transferred to microfluidic cultures. (B) Simulation results of the steady-state oxygen concentration in the vertical cross section of the PDMS chip. Color bar shows the normalized oxygen concentration (c’) between 0 and 1. The section of cell culture and gas flow channels is also indicated. (C) Simulated steady-state profile of the scaled oxygen concentration at the bottom of the culture chamber as indicated in B, with or without cell. (D) Schematic section S1 (left) and top view (right) of the microfluidic gradient chip. Red: 95% N2/5% CO2 gas flow channels. Cyan: culture chambers. (E) Picture of the microfluidic chip filled with dyes according to the colors in D. (F) Fluorescent images of the culture chambers filled with an oxygen-sensitive ruthenium solution in PBS 1X, without gas inflowing into the gas channel (left in red) and at steady-state with nitrogen and carbon dioxide gas mixture flowing at 1 mL/min (right in blue). (G) Normalized fluorescent intensity along the culture channel cross-sections highlighted by red and blue lines in F. Red: control condition without gas flow. Blue: steady-state condition with gas flowing at 1 mL/min flow rate at the right side of the microchannel.
