Figure 1. Association of nanoparticles with alveolar macrophages in presence of surfactant proteins as determined by flow-cytometry.

(A) Starch-modified (ST) magnetite nanoparticles (mNP) or (B) Phosphatidylcholine-modified (PL) mNPs (1.532×10¹⁰/ml) were exposed to alveolar macrophages in the absence or presence of increasing surfactant protein concentrations and incubated for 90 min. Cells with Fl-1>10¹ were considered as positive cells for nanoparticle association and uptake (expressed as percent of positive cells with respect to total cells) compared to control (cells only). Data shown as mean ± SD (n≥3). Asterisk indicates a significant difference with p<0.05, compared to mNP in the absence of proteins.