Fig 6.

Neutrophil and bacteria coculture on human acellular vessel (HAV) and expanded polytetrafluoroethylene (ePTFE). Representative scanning electron microscopy (SEM) images of S.aureus with and without freshly isolated neutrophils after 5 hours of seeding onto HAV and ePTFE. Red arrows indicate S.aureus bacteria. Clusters of bacteria scattered on surface of HAV (A-C), but accumulated within the interstitial nodes of the ePTFE matrix (D-F). Polymorphonuclear neutrophils (PMN) on HAV formed NETs with ensnared bacteria (G). Bacteria with cytoplasmic leakage and membrane integrity loss are seen near PMNs on the HAV (H and I, yellow arrows), indicating bacterial cell death. Bacteria near PMNs on ePTFE often had normal morphology (L) and did not seem to be within NETs (J and K), suggesting that, by 5 hours, PMNs on ePTFE were less effective than those on HAV at eliminating bacteria. The magnified images on the right are of the area depicted by dashed boxes in images on the left.