Figure 1.

Schematic showing setup and culture of constructs within bioreactor. Normal human bronchial epithelial (NHBE) cells are placed on the collagen-coated polytetrafluorethylene (PTFE) membrane bonded to an absorbent polyvinylidene fluoride (PVDF) sponge layer and allowed to adhere (A). (B and C) Scanning electron micrographs of the two construct layers, pictured without cells, showing their relative porosity and structure. Scale bars: 2 µm. This construct is rolled into a cylinder and placed inside the reactor vial where it aligns with the walls. The reactor is sealed, with ports to allow gas and media exchange (D). The reactor vial is half filled with media and rolled continuously throughout culture, generating intermittent air–liquid interface (ALI) and submerged conditions (E). When ready for cell harvesting and analysis, the construct is removed from the reactor, and the upper PTFE membrane with attached cells is processed (F).