Fig. 2.

eECM cell-binding domain (CBD) density and stiffness modulate the cell area of Caco-2 cells within mature monolayers. (a) Representative micrographs of DAPI-stained nuclei of Caco-2 monolayers demonstrating decreased cell area (and hence higher cell density) in monolayers cultured on eECM substrates with decreased CBD density or decreased stiffness. (b) Caco-2 projected cell area decreases when cultured on eECM with decreasing CBD density (top) and decreasing elastic modulus (E) (bottom). (c) Scanning electron microscopy (SEM) images and manual tracing of cell boundaries on representative matrices and explanted primary murine small intestinal tissue. (d) Quantification of SEM micrographs confirms that Caco-2 monolayers on eECM substrates with lower stiffness and fewer CBD have projected cell areas more similar to primary murine intestinal tissue compared to collagen I. (e) Cross-sectional z-stacks of Caco-2 monolayers on collagen and representative eECMs, stained for the tight junction protein JAM-A (red) and nuclei (blue), demonstrate the maintenance of proper cell polarity on all substrates and the presence of more columnar shaped cells on eECM of lower stiffness and fewer CBD. *p < 0.05, ***p < 0.001, ****p < 0.0001. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)