Liver Histopathological Changes Related to Intraperitoneal Administration of Salicylic Acid/Fe3O4 Nanoparticles to C57BL/6 Mice

Abstract

With a simple synthesis and easy engineering of physicochemical properties, iron oxide nanoparticles (IONPs) have become widely used in multiple biomedical applications. The study of IONPs toxicity has become an important issue, especially as the results reported so far are contradictory and range from lack of toxicity to cellular toxicity. The aim of this study was to evaluate the histopathological changes induced in mouse liver by long-term intraperitoneal injection of low doses of IONPs functionalized with salicylic acid (SaIONPs). The study was performed on C57BL/6 mice that received by intraperitoneal injection (IP), every two days, 0.6ml of SaIONPs aqueous suspension (35mg/kg body weight SaIONPs that contained 20mg/kg body weight of Fe3O4) for 28 days. The results of this study showed that the cumulative dose of 105mg/kg body weight SaIONPs (62mg/kg body weight of Fe3O4) induced histopathological changes in the subcapsular region of the mouse liver, possible by the release of salicylic acid into the peritoneal cavity. The cumulative dose of 244mg/kg body weight SaIONPs (145mg/kg body weight of Fe3O4) induced liver centrilobular necrosis, which requires the use of lower doses in biological applications. However, this may prove to be beneficial in the case of targeted accumulation of SaIONPs.

Keywords: Iron oxide nanoparticles; hidropic degeneration; rat liver; salicylic acid; toxicity.

Figure 1

Liver passage of the IP-administered SaIONPs. SaIONPs-loaded circulating macrophages into the portal vein (black arrowheads) (a) and central vein (circle) (d). Cluster of SaIONPs-loaded macrophages (white arrows) on the liver capsule (b). Zonal accumulations of high SaIONPs-loaded hepatocytes (c). Homogeneous distribution of SaIONPs-loaded macrophages (black arrows) and focal distribution of SaIONPs-loaded hepatocytes (white arrowheads) in the liver lobule (e). Variation of the relative areas of SaIONPs deposits (RAD) in the liver of mice treated with 3 (D7), 7 (D14), and 10 (D21) doses of nanoparticles (Mann-Whitney U test, *p <0.05). Perls staining. Scale Bar=10µm

Figure 2

Subcapsular hydropic degeneration (black arrowheads) relative to (a) or distant from (b) extracapsular clusters of SaIONPs-loaded macrophages, associated with nuclear polymorphism, binucleate hepatocytes (white arrowheads), lytic necrosis of hepatocytes (white arrows) and foci of subcapsular liver necrosis (black star) (c, d). Karyolysis (black arrows) (e) associated with SaIONPs-loaded nuclei (white arrows) (f). Liver harvested on the 7th day of the experiment. Masson tricromic Goldner (a,b,c,f), Perls (e) and HE (d) stainings. Scale Bar=10µm

Figure 3

Extended (a, b) or centrilobular (c,d,f,g) liver necrosis, with massive accumulation of SaIONPs-loaded macrophages (b,d,g), which can block sinusoids and portal veins (h). Liver harvested on the 14th (c,f) or 21th (a,b,d,e,g h) day of the experiment. Perls (a-e) and HE (f-h) stainings. Scale Bar=20µm (a b), 10µm (c-h)

Figure 4

Extensive nucleolysis (white arrows) following the loading of perilesional hepatocytes nuclei (black arrows) with SaIONPs/Fe3O4 resulting from the degradation of SaIONPs-loaded cells in necrosis foci. Liver harvested on the 28th day of the experiment. Masson tricromic Goldner (a), Perls (b,d) and HE (c) stainings. Scale Bar=10µm