The effect of membrane properties on cell growth in an ‘Airway barrier on a chip’

An important factor in determining epithelial cell barrier integrity in an in-vitro system is the support membrane on which cells are cultured. In this work a custom airway barrier on chip platform was used to investigate the impact of various support membranes on bronchial epithelial cell growth and barrier formation. The membranes had different pore sizes (0.4 μm or 3 μm), densities (1 × 108, 8 × 105, 1.6 × 106 pores/cm2), thicknesses (9 μm, 12 μm, 20 μm) and chemical treatments (polyvinylpyrrolidone or oxidative). Trans Epithelial Electrical Resistance (TER) data for the various cell constructs was compared with cells grown on commercial Transwells®. The results demonstrate differences in barrier integrity and structure, with cells grown under flow having reduced barrier integrity (lower TER) compared to the same cells grown without flow. Bronchial epithelial cells grown in the dynamic (with flow) barrier on a chip platform consistently grew on 0.4 μm pore membranes with higher TERs, compared to 3 μm pore membranes with thinner cell layers, and to cell migration where cells translocated to the basolateral region.