Fig. 4. In situ colonisation of valves by host cells.

a Left; schematic leaflet with regions of interest. Right; one representative valve leaflet stained with H&E. Scale bar 1 mm. b Belly and hinge regions for one representative valve for each time point. Colours indicate nuclei (dark purple) and tissue (pink), Scale bar is 100 µm. Cells infiltrate abundantly in hinge regions, while belly regions are free from cells. c Endothelium in belly regions indicated with an arrow. Scale bar is 50 µm. d Left: Semi-quantification of cells present per mm² in and on the scaffold in regions of interest counted in H&E staining. Error bars are standard deviations. Bar charts are means. The hinge regions of the valves were colonised by host cells from 3 months onwards. Right: DNA quantification, normalised to valve dry weight, measured for half a valve. Box plot present maximum and minimum values, middle horizontal bar represents the mean. Limited amount of DNA was measured with exception for one 9 month and one 12 month valve, ea. #9.1 and #12.1.