Fig. 3

Comparison of morphological appearance, barrier integrity, permeability and structure of developed models using human primary cell lines. Representative morphological appearance, SEM images and IF staining of developed models; A static mono-cell culture (NHBE), B static co-culture (NHBE-NHLF), C dynamic mono-cell culture (CNBio NHBE), D dynamic co-culture (CNBio NHBE-NHLF) on the Day 25. The morphology of cells at the end of culture (Day 25 of culture). Scale bar represents 200 µm. For SEM, images showed the morphology of cells on the apical surface of the model; scale bar, 10 µm. For IF staining, ZO-1 (red) and DAPI (blue) staining were used to demonstrate the continuous tight junctional connections; scale bar, 50 µm. E The electrical resistance of the models over a period of 25 days of culture; ALI condition was performed on Day 7 for all models; F The permeability of FITC-Dextran into the basolateral compartment of all the models. Negative (-ve) control was the medium only without FITC-Dextran. Positive (+ ve) control was the empty insert without cells followed the same protocol as the inserts with cells. Error bars denote standard deviation. Statistical significance was shown between positive (+ ve) control and CNBio NHBE; **: P < 0.01. G Representative histological cross-sections (H&E staining) and IF staining display essential epithelial features, including acetylated α-tubulin (green, marker for ciliated cells) and MUC5B (red, marker for goblet cells) for the static culture and dynamic culture. Objective 40x, scale bar represents 50 µm