Nanoparticle uptake by alveolar macrophages in dependence on surfactant proteins as studied by confocal microscopy.

<p>Representative micrographs are shown for Starch-modified (ST) magnetite nanoparticles (mNP) (A, C) or Phosphatidylcholine-modified (PL) mNPs (B, D) (1.532×10¹⁰/ml, in green) after 90 min exposition to alveolar macrophages (MH-S cells; membrane in red) in absence (mNP only in buffer (A, B) or presence of (C) SP-D (10 µg/ml) or (D) SP-A (10 µg/ml). Scale bar indicates a distance of 20 µm. (E) Particle uptake determined by visual counting of cells with at least one nanoparticle internalized related to total cell count (% positive cells). Data shown as mean ± SD (n = 14 images). Asterisk indicates a significant difference with p<0.05.