Figure 10.

Monocyte morphology and interaction with opsonized zymosan particles or Staphylococcus epidermidis on AuNP, Au and Thx as visualized with SEM.

Notes: Monocytes on AuNP (A), Au (B), and Thx (C) surfaces in general demonstrated a rounded morphology with a moderate number of membrane ruffles/ridges with nonpreferential directions. The cell–material surface interaction was morphologically evident in areas with cytoplasmic extensions, in the form of either distinct, thin spikes of variable length (arrow in A) or thin, spread extensions (arrows in B and C). Cells with a polarized morphology were also observed (examples in B and C), suggestive of being in the process of attachment, detachment, or migration. Details of monocyte–zymosan particle interactions are observed morphologically in (D–F). Typically, oval-shaped zymosan particles with fine, undulating ridges were clearly distinguishable. Several zymosan (z) particles were enveloped by pseudopods (arrows). A large number of Staphylococcus epidermidis (0.5–1-μm round-shaped cocci) were detected in close association with the monocyte membrane (G–I). Multiple bacteria (some of which are denoted b) were clustered and enveloped by large, thin-walled pseudopods (arrows) in an apparent phagocytic process.

Abbreviations: Au, smooth gold surface; AuNP, nanostructured gold surface; SEM, scanning electron microscopy; Thx, tissue culture-treated plastic cover slip.