Nanoscale zerovalent iron particles induce differential cytotoxicity, genotoxicity, oxidative stress and hemolytic responses in human lymphocytes and erythrocytes in vitro

Abstract

The growing usage of nanoscale zerovalent iron particles (nZVI) in the remediation of soil, ground/surface water has elicited large‐scale environmental release triggering human exposure. The size of nanomaterials is a key regulator of toxicity. However, the effect of a variable size of nZVI on genotoxicity is unexplored in human cells. To the best of our knowledge, in this study, the cytotoxic, genotoxic and hemolytic potential of nZVI‐1 (15 nm) and nZVI‐2 (50 nm) at concentrations of 5, 10 and 20 μg/mL was evaluated for the first time in human lymphocytes and erythrocytes treated for 3 hours. In erythrocytes, spherocytosis and echinocytosis occurred upon exposure to nZVI‐1 and nZVI‐2, respectively, leading to hemolysis. Lymphocytes treated with 20 μg/mL nZVI‐2 and 10 μg/mL nZVI‐1, incurred maximum DNA damage, although nZVI‐2 induced higher cyto‐genotoxicity than nZVI‐1. This can be attributed to higher Fe ion dissolution and time/concentration‐dependent colloidal destabilization (lower zeta potential) of nZVI‐2. Although nZVI‐1 showed higher uptake, its lower genotoxicity can be due to lesser Fe content, Fe ion dissolution and superior colloidal stability (higher zeta potential) compared with nZVI‐2. Substantial accumulation of Ca2+, superoxide anions, hydroxyl radicals and H2O2 leading to mitochondrial impairment and altered antioxidant enzyme activity was noted at the same concentrations. Pre‐treatment with N‐acetyl‐cysteine modulated these parameters indicating the indirect action of reactive oxygen species in nZVI‐induced DNA damage. The morphology of diffused nuclei implied the possible onset of apoptotic cell death. These results validate the synergistic role of size, ion dissolution, colloidal stability and reactive oxygen species on cyto‐genotoxicity of nZVI and unlock further prospects in its environmental nano‐safety evaluation.

Transcriptional Response of Blood Mononuclear Cells from Patients with Inflammatory and Autoimmune Disorders Exposed to “Krakow Smog”

“…PM 10, and especially PM 2.5, are considered the most harmful to human health [ 15 , 17 , 18 , 19 , 20 , 21 , 22 ]. They can penetrate the lower respiratory tract and translocate from the lung to the bloodstream, which may affect the functions of blood erythrocytes, platelets, and leukocytes [ 23 , 24 , 25 , 26 ]. Moreover, it was shown that ambient PM might contribute to the initiation and development, among others, of atherosclerosis (AS) [ 27 ], rheumatoid arthritis (RA) [ 3 ], and multiple sclerosis (MS) [ 28 ].…”