Figure 3.

Neutrophil transmigration through a collagen matrix. (a) Even in the presence of endothelial cells and supplemented collagen I gel, neutrophils transmigrate to the abluminal channel. The presence of basal gel (below the nanomembrane) does not significantly reduce the amount of migrated cell population as observed from the representative images of cells on the cover-slip 3 h after addition (17.54 ± 4.29% in absence of basal gel, and 19.89 ± 5.52% in the presence of basal gel, n = 3 each; the percentage of cells calculated by dividing the number of cells in the basal chamber 3 h later to the number of cells in the top chamber at the onset of migration). In the absence of endothelial cells, neutrophils (hPMN) migrate fastest due to potential absence of any steric inhibition. Scale bar = 100 μm. (b) Scanning electron microscopy (SEM) analysis shows the ability of hPMNs to transmigrate through the collagen gel, eventually residing on the underlying nanomembrane.