Figure 8.

Formation of a mucus bilayer in the human Colon Chip. (A) A pseudocolor 3-dimensional reconstruction of representative z-stack confocal images of the Colon Chip perfused with 1-μm fluorescent beads (magenta) 3, 7, or 14 days after monolayer formation; the cells were live stained with calcein AM (light green). Images are representative of 2 independent experiments. (B) Quantification of the thickness of the inner (impenetrable) and outer (penetrable) mucus layers based on the distribution of the beads (n = 3 chips, 3 independent regions per chip; all values were significantly different between all days). *P < .05 for the inner and outer layers. Similar results were obtained in 2 independent experiments. (C) Scanning electron micrograph of a cross-section of the epithelium within a Colon Chip showing the presence of a filamentous network within the mucus layer in direct contact with the apical surface of the cells. The bracket indicates the PDMS membrane. Image is representative of 2 independent experiments. Scale bar: 50 μm. All data represent means ± SEM.