Figure 5.

Schematic representation of the three-dimensional in vitro cellular intestinal model Caco-2. (A) The intestinal epithelium in vivo is mainly composed of enterocytes and goblet cells [255], which represents about 90% of intestinal cells of the brush border membrane [256,257]. These are covered by a viscoelastic gel: the mucus layer. This physical barrier is synthesized and secreted by goblet cells and serves as a protective layer for the underlying epithelium. (B) Three-dimensional Caco-2 monoculture in the “Transwell^® system”. The intestinal cell line Caco-2 is cultured in inserts on a permeable membrane, and, in most cases, composed of polycarbonate. This results in three compartments: an apical compartment representing the intestinal lumen, a basolateral side corresponding to the serosal surface of enterocytes, and the intestinal barrier formed by differentiated Caco-2 cells.