Fig. 4. Quantification of TNF-α secretion in RAW264.7 macrophages.

(A) Representative immunofluorescence images showing TNF-α in cells fixed after 6 hours of culture on various substrates as indicated (scale bar, 40 μm). a.u., arbitrary units. (B) Distribution plots of intracellular TNF-α intensity. For “Pam₃ + IgG,” n = 334 cells (1.0 μm), 387 (1.5 μm), 352 (2.0 μm), and 468 (2.5 μm). For “Pam₃ only,” n = 334 cells (1.0 μm), 463 (1.5 μm), 420 (2.0 μm), and 483 (2.5 μm). For “IgG only,” n = 351 cells (1.0 μm), 459 (1.5 μm), 427 (2.0 μm), and 468 (2.5 μm). For “No ligands,” n = 364 cells (1.0 μm), 432 (1.5 μm), 460 (2.0 μm), and 449 (2.5 μm). (C) Plots showing average intracellular TNF-α intensities as a function of nanoarray spacing with different ligand functionalization as indicated. Each data point represents average ± SD of data shown in (B) from 10 images.