Figure 6.

Phase contrast microscope image of the HUVEC cell sheet detaching from copolymer after 8 min at 4°C. (a) The area where cells are still attached in their typical cobblestone morphology and (b) the area where the cell sheet has already detached. The arrows indicate the direction of detachment and the detached sheet is seen to be folding over upon itself. Detachment occurs from the outer edge of the sheet in towards the centre as a result of the copolymer dissolving, as it becomes exposed to the aqueous media. Detachment does not occur initially at the centre because the very tight intercellular junctions do not allow a sufficient volume of media to pass through to cause complete dissolution of the copolymer. Scale bar, 130 μm.