Figure 6: Cell growth on the HAIRS-xNR material.

(a) The cells form focal adhesions on the tips of the microstructures. Representative reconstructed 3D confocal image showing a cell that was immunostained for the focal adhesion protein vinculin (green: actin (phalloidin fluorescent counterstain), red: fluorescently labelled anti-vinculin antibody, blue: nucleus (DAPI fluorescent counterstain) and autofluorescence from the microstructures). The white arrows point at different microplates where multiple micron-scale vinculin-positive complexes are evident. The microstructure dimensions and spacing are 2 μm wide, 10–15 μm long, 5 μm between neighboring rows and 10–25 μm between neighboring columns. (b–e) Representative 3D confocal images showing examples of the cell growth and alignment after 24 h at 31 °C on substrates with different microstructure geometries. The cells (green) were grown on top of fluorescently labelled HAIRS samples (blue: microstructures labelled with pyrromethene 546, red: hydrogel in its swollen state labelled with DY-485 XL, green: cells labelled with HCS CellMask Deep Red Stain). The microstructure dimensions and spacing in the surface plane are: (b) 2 μm wide, 15 μm long, 5 μm between rows and 25 μm between columns, (c) 2 μm wide, 5 μm long, 5 μm between rows and 5 μm between columns, (d) 2 μm wide, 10 μm long, 5 μm between rows and 5 μm between columns, and (e) 2 μm wide, 5 μm long, 5 μm between rows and 10 μm between columns. All scale bars are 10 μm.