Engineered Nanomaterial Impact in the Liver following Exposure via an Intravenous Route–The Role of Polymorphonuclear Leukocytes and Gene Expression in the Organ

Ali Kermanizadeh

doi:10.4172/2157-7439.1000157

Abstract

Abstract Background and methods: Following exposure via a number of routes (inhalation, ingestion or injection), some Nanomaterials (NMs) translocate to secondary tissues, prominently the liver. This study investigated the effects of an array of NMs, varying in their physicochemical characteristics, consisting of two types of Zinc Oxide (ZnO), two Multiwalled Carbon Nanotubes (MWCNT), one silver (Ag) and one titanium dioxide (TiO2) on the liver, following Intravenous (IV) exposure of C57/BL6 mice. The animals were exposed to either a single dose of NM (128 μg/ml–100 μl) or three doses of (64 μg/ml–100 μl), every 24 hr. Animals were dissected 6, 24, 48 and 72 hr after the single IV injection, or 72 hr after the triple injection regime. Results and conclusions: A Myeloperoxidase (MPO) assay was utilised to quantify neutrophil influx into the tissue. However, as MPO is also found in other granulocytes in smaller quantities, the neutrophils in the liver tissue were also labelled, using a specific neutrophil cell surface marker (Ly-6B.2). A wide array of NMs (including ZnO, Ag, TiO2 and MWCNT) induced a neutrophil influx into the liver, as early as 6 hr post IV exposure. However, the neutrophils were only involved in the initial phases of the immune response against the NMs, as the leukocyte numbers had returned to control levels after 48 hr. Finally, analysis of mRNA expression in mice livers showed alterations in levels of C3, IL6, IL10, CXCL2 and ICAM-1.

Highlights

Engineered Nanomaterials (NMs) are being developed and exploited because of their unusual and interesting properties exhibited at the nano-scale, compared to larger materials [1,2]
As MPO is found in other granulocytes in smaller quantities, the neutrophils in the liver tissue were labelled, using a specific neutrophil cell surface marker (Ly-6B.2)
The neutrophils were only involved in the initial phases of the immune response against the NMs, as the leukocyte numbers had returned to control levels after 48 hr

Summary

Results and conclusions

A Myeloperoxidase (MPO) assay was utilised to quantify neutrophil influx into the tissue. As MPO is found in other granulocytes in smaller quantities, the neutrophils in the liver tissue were labelled, using a specific neutrophil cell surface marker (Ly-6B.2). A wide array of NMs (including ZnO, Ag, TiO2 and MWCNT) induced a neutrophil influx into the liver, as early as 6 hr post IV exposure. The neutrophils were only involved in the initial phases of the immune response against the NMs, as the leukocyte numbers had returned to control levels after 48 hr. Analysis of mRNA expression in mice livers showed alterations in levels of C3, IL6, IL10, CXCL2 and ICAM-1

Introduction

Materials and Methods

Results and Discussion