Abstract
Genotoxicity is an important endpoint to assess for understanding the risks associated with nanoparticles (NPs). Most genotoxicity studies performed on NPs have focused on primary genotoxicity analyzed by comet- or micronuclei (MN) assay using microscopic scoring. Here, we established a protocol for a more efficient version of MN assessment using flow cytometry and, importantly, both primary and secondary (inflammation-driven) genotoxicity was assessed. Human bronchial epithelial cells (HBEC-3kt) were exposed to nickel oxide (NiO) NPs directly or indirectly. The indirect exposure was done to assess secondary genotoxicity, and in this case immune cells (THP-1 derived macrophages) were exposed on inserts and the HBEC were cultured in the lower compartment. The results in monocultures showed that no increased MN formation was observed in the HBEC cells but instead a clear MN induction was noted in THP-1 cells indicating higher sensitivity. No MN formation was either observed when the HBEC were indirectly exposed, but an increase in DNA strand breaks was detected using the comet assay. Taken together, the present study emphasizes the feasibility of assessing primary and secondary genotoxicity and, furthermore, shows a clear MN induction in THP-1 monoculture following NiO NPs exposure.
Highlights
Nanoparticles (NPs) possess distinct physicochemical properties, and their unique characteristics makes them novel entities for a wide range of applications in medicine, engineering, pharmaceuticals, cosmetics, and electronics etc., (Salata, 2004; Ealia and Saravanakumar, 2017)
Primary genotoxicity: MN formation was evaluated after 48 h exposure of HBEC and THP-1 monocytes (THP)-1 cells to different concentrations of nickel oxide (NiO) NPs (5, 10, and 25 μg/mL)
The results showed no significant change in MN induction in HBEC cells (Figures 2A,B), whereas in THP-1 cells, a clear increase was observed (7.5% MN) at 25 μg/ mL compared to control (2.3% MN) (Figure 3)
Summary
Nanoparticles (NPs) possess distinct physicochemical properties, and their unique characteristics makes them novel entities for a wide range of applications in medicine, engineering, pharmaceuticals, cosmetics, and electronics etc., (Salata, 2004; Ealia and Saravanakumar, 2017). Their extensive production and usage lead to a demand for toxicity evaluation as well as assessment of health risks at occupational and environmental settings (Kessler, 2011; Batley et al, 2013). Exposure is common at nickel refineries, metal alloy production sites and at occupational setting where welding is performed (Klein and Costa, 2015; Pesch et al, 2019). Several studies have shown genotoxicity following exposure of lung cells to NiO NPs (Capasso et al, 2014; Di Bucchianico et al, 2018; Akerlund et al, 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
