Figure 4. Calu-3 cells underwent different morphologic changes on the nanograss in the “in-3D” culture.

(a) Calu-3 cells stabilized with monolayer morphology with extensive buckling on the nanograss while maintained as monolayer on the flat substrates on Day 15. Note that the gap (yellow arrowheads) between the basal surface of the Calu-3 cell sheet and the nanograss is about 10 μm after the folding. White dashed line indicates the cell-substrate interface. (b) The cell height of Calu-3 cells increased about two folds on the nanograss compared to that cultured on the flat substrates. Scale bars, 20 μm (a) and 10 μm (b).