Figure 3From: Comparative iron oxide nanoparticle cellular dosimetry and response in mice by the inhalation and liquid cell culture exposure routesSPIO nanoparticle mass deposited in each region of the lung (top) and regional dosimetry (bottom panel) calculated with the Balb/c specific version of MPPD. Target cell doses are presented in units of mass per surface area of cells for all airways, and as pg/macrophage for the alveolar region only to correspond to experimental in vitro dose-response data. Given a density of 5.2 grams/cm3, a picogram of SPIO particles would contain 154,015 primary 13 nm diameter particles with a surface area of 8.87 × 10−7 cm2.Back to article page