Figure 1

Viability of substrate tissue. (left) Sections of PI/FDA-stained cartilage components from (i) leveled and (ii) hole-punched substrate cylinders, and (iii) cartilage discs were analyzed by fluorescence microscopy. Viable cells appear green and apoptotic cells red. (right) Histomorphometric analysis was performed to determine the percentage of apoptotic cells as measure for the viability of the tissue. For each image areas of different red tones were determined and presented in new colors. High content of apoptotic cells was indicated in red, moderate in orange, low in yellow and areas with high content of viable cells were shown in green (see Methods). Only a small proportion of cells was found apoptotic (<18%), hence 48 h post preparation cartilage components of the substrates are in a viable condition for adhesive strength measurements. Bar = 200 μm.