Haemodynamic flow conditions at the initiation of high-shear platelet aggregation: a combined in vitro and cellular in silico study

Figures

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  Figure 1.. Side view of the geometric design of both microfluidic flow chambers: (a) Casa’s flow chamber and (b) van Rooij’s flow chamber. The depth of both flow chambers is 480 μm (z-direction, not shown). (c) A schematic of the experimental set-up. PBS, phosphate-buffered saline.

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  Figure 2.. Microscopic images at the start of the experiment: (a) Casa’s flow chamber and (b) van Rooij’s flow chamber. The white points indicate the corners of the stenotic region. The black arrows point to the vertical line on which the alignment of the normalized pixel intensity was based.

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  Figure 3.. A side view of the cell-based WB simulation with Q = 2.1 × 10−9 m3 s−1 in van Rooij’s flow chamber at the last time step (t = 0.35 s). The RBCs are shown in red and the platelets yellow.

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  Figure 4.. A side view of the cell-based PRP simulation with Q = 2.3 × 10−9 m3 s−1 in van Rooij’s flow chamber at the last time step (t = 0.35 s). Platelets are shown in yellow.

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  Figure 5.. The RBC flux averaged over 0.30 s in van Rooij’s flow chamber for the cell-based WB simulation with Q = 2.1 × 10−9 m3 s−1.

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  Figure 6.. The platelet flux averaged over 0.30 s in van Rooij’s flow chamber for (a) the cell-based WB simulation with (Q = 2.1 × 10−9 m3 s−1) and (b) the cell-based PRP simulation (Q = 2.3 × 10−9 m3 s−1).

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  Figure 7.. The platelet residence time averaged over 0.30 s in a flow chamber on van Rooij’s chip for (a) the cell-based WB simulation (Q = 2.1 × 10−9 m3 s−1) and (b) the cell-based PRP simulation (Q = 2.3 × 10−9 m3 s−1).

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  Figure 8.. The xy-component of the shear rate measured at 1 μm from (a) the glass wall and (b) the PDMS wall in the cell-based and continuum blood flow simulations. The continuum WB simulation result is shown in green and the cell-resolved WB simulation results are shown in light blue for every 10 ms. The light red lines represent the cell-based PRP simulation for every 10 ms and the dotted dark red line represents the continuum PRP simulation. The average shear rate over time of the cell-based simulations is shown by the solid blue and the red lines, respectively, for WB and PRP.

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  Figure 9.. The xy-component of the stress measured at 1 μm from the (a) glass wall and (b) the PDMS wall in the cell-based and continuum blood flow simulations. The continuum WB simulation result is shown in green and the cell-resolved WB simulation results are shown in light blue for every 10 ms. The light red lines represent the cell-based PRP simulation for every 10 ms and the dotted dark red line represents the continuum PRP simulation. The averages of the cell-based simulations are shown by the solid blue and red lines, respectively, for WB and PRP.

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  Figure 10.. An example of an image at occlusion time for Casa’s flow chamber (a,b) and van Rooij’s flow chamber (c,d) perfused with WB and PRP. The vertical white lines in (a) and (b) indicate the contraction and expansion areas for Casa’s flow chamber. The stenotic section is located between the second and third white lines. (a) Casa WB, (b) Casa PRP, (c) van Rooij WB, (d) van Rooij PRP.

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  Figure 11.. Examples of initial frames of platelet aggregate formation experiments in van Rooij’s flow chamber. The images were taken at the point in time when the first platelet aggregates became visible. In the top row, a selection of the PRP experiments is shown and on the bottom, a selection of the WB experiments. The white arrows point to small platelet aggregates on the surface of the stenotic section and the yellow arrows point to platelet strings that are attached to the back corner of the stenosis.

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  Figure 12.. Examples of initial frames of platelet aggregate formation experiments in Casa’s flow chamber. The images were taken at the point in time when the first platelet aggregates became visible. In the top and the second row, a selection of the PRP experiments is shown. On the second and the bottom row, a selection of the WB experiments are shown. The white arrows point to small platelet aggregates on the surface of the stenotic section. The vertical white lines indicate the contraction and expansion areas of the flow chamber. The stenotic section is located between the second and third white lines.