Toxicity of Metal Oxide Nanoparticles in Mammalian Cells

Abstract

Along with existing and emerging use of nanoscale materials, growing concerns have arisen about their unintentional health and environmental impact. The objective of the ongoing study was to assess the toxicity profile of metal oxide nanoparticles proposed for use in industrial production methodology. Metal oxide nanoparticles used in this study included TiO2, ZnO, Fe3O4, Al2O3, and CrO3 with particle sizes ranging from 30 to 45 nm. Cellular morphology, mitochondrial function, membrane leakage of lactate dehydrogenase (LDH), permeability of plasma membrane, and apoptosis were assessed under controlled and exposed conditions (2 to 72 h of exposure). The microscopic studies demonstrated that nanoparticle-exposed Neuro-2A cells (especially ZnO) at doses >100 microg/mL became abnormal in size, displaying cellular shrinkage, and detachment from the surface of flasks. Mitochondrial function decreased significantly in the cells exposed to ZnO at 50 to 100 microg/mL. However, Fe3O4, Al2O3, and TiO2 had no measurable effect on the cells until the concentrations reached greater than 200 microg/mL. LDH leakage significantly increased in the cells exposed to ZnO (50 to 100 microg/mL), while other nanoparticles tested displayed LDH leakage only at higher doses (>200 microg/mL). Flow cytometer tests showed that apoptosis took place in cells exposed to ZnO nanoparticles. More cells became necrotic as the concentrations increased.

PLLA/ZnO nanocomposites: Dynamic surfaces to harness cell differentiation

“…The reported cytotoxic zinc concentration, using different cell types, in culture is 150 µM, [32] which suggests that the amount of zinc released in our system is slow enough to not create adverse cellular effects due to the presence of zinc.…”

“…We first wanted to disregard the potential cytotoxicity of the system -some authors have reported that ZnO might be cytotoxic under certain conditions - [31][32][33] using a LIVE/DEAD ® assay. To do so, C2C12 were seeded onto the surfaces with growth medium for 1 week.…”

“…[30] ZnO nanorod-coated surfaces were shown to be cytotoxic to macrophages regardless of the underlying topography [31] and has been reported to be cytotoxic to neuroblastoma cells and vascular endothelial cells with similar Zn concentrations (~150 µM). [32,33] A recent study showed that electrospun nanofibres of ZnO/TiO 2 NPs resulted in increased cell proliferation of C2C12 myoblasts, although cell differentiation was not addressed. [13] In this work, ZnO NPs have been loaded into a PLLA matrix to promote cell differentiation.…”

The effect of zinc oxide nanoparticles on mouse spermatogenesis

“…Delouise reported that ZNPs are nontoxic to cultured human dermal fibroblasts [13]. Other reports suggest that these nanoparticles are toxic to neuroblastoma cells [14], vascular endothelial cells [15], liver and kidneys [16,17]. In present study, toxic effects of ZNP on the mouse spermatogenesis were investigated.…”

(Q)SAR modelling of nanomaterial toxicity: A critical review

“…There is now a growing body of literature on the potential undesirable effects caused by the exposure to different types of ENMs (Horie & Fujita, 2011;Jeng & Swanson, 2006;Karlsson, Gustafsson, Cronholm, & Möller, 2009;Magrez, et al, 2006). Although the awareness of the potential adverse effects of ENMs is increasing, there are still numerous unanswered questions which complicate the appropriate evaluation of toxicity at the nano-scale dimension.…”