Skip to main content
. Author manuscript; available in PMC: 2012 Sep 1.
Published in final edited form as: Biomaterials. 2011 Sep;32(26):6291–6301. doi: 10.1016/j.biomaterials.2011.05.024

Figure 4. Histological time course of primary organs of nanoparticle elimination after administration of PEG-MNPs.

Figure 4

Figure 4

Representative micrographs of elimination tissues stained to produce Prussian Blue from MNP iron and counterstained with nuclear fast red to visualize D5 (A) and D20 (B) distribution in tissues. Micrographs visually confirm tissue concentrations are high and continue to increase in the red pulp of the spleen. Increases in spleen Prussian Blue intensity over time generally agrees with quantitative data shown in Figure 3. MNP distribution is observable in the liver, at intensities less than that observed for spleen at later time points. Only minute instances of Prussian Blue can be found in lung, with no detectable distribution in the kidney for either type of nanoparticle. Lack of Prussian Blue in lung and kidney indicates that much of the MNP content detected by ESR is limited to tissue blood that washes away during tissue preparation for histology.