Figure 2. Comparison of D & PEG-MNP biodistribution in liver and spleen tissues (12 mg Fe/kg, 1 hr post administration, n=9).
D distributes in both the liver and spleen during plasma clearance, typical of most studied MNPs. For D5 and D20, statistically lower levels of MNPs are found in the spleen (2.2–2.6-fold reduction from D), and more dramatically in the liver (11.3–12.5-fold reduction from D). Data substantiate previously obtained pharmacokinetic results that indicate the long-circulating behavior of PEG-MNPs [16]. Moreover, the lack of proportional reductions in tissue MNP concentration between the spleen and liver suggest that the liver is distributed with PEG-MNPs to a reduced extent compared to D. Conversely, the spleen appears to possess enhanced distribution suggesting an increased role in plasma clearance of MNPs.
