Fig. 1.

Schematic of proposed assay to improve paracellular transport for in vitro drug screening. (a) Schematic of the Caco-2 monolayer assay in which drug molecules are added to the apical side and their transport to the basolateral side is monitored over time to predict intestinal absorption. (b) Schematic of key cell-cell and cell-matrix interactions that contribute to regulation of paracellular transport through tight junctions that connect neighboring cells. (c) Schematic representation and amino acid sequences of the engineered extracellular matrices (eECMs) used to replace the traditional collagen I matrix in the standard Caco-2 monolayer assay.