Toxicological effects of the mixed iron oxide nanoparticle (Fe₃O₄ NP) on murine fibroblasts LA-9

ABSTRACT

The increase in large-scale production of magnetic nanoparticles (NP) associated with the incomplete comprehensive knowledge regarding the potential risks of their use on environmental and human health makes it necessary to study the biological effects of these particles on organisms at the cellular level. The aim of this study to examine the cellular effects on fibroblast lineage LA-9 after exposure to mixed iron oxide NP (Fe₃O₄ NP). The following analyses were performed: field emission gun–scanning electron microscopy (SEM-FEG), dynamic light scattering (DLS), zeta potential, ultraviolet/visible region spectroscopy (UV/VIS), and attenuated total reactance-Fourier transform infrared (ATR-FTIR) spectroscopy analyses for characterization of the NP. The assays included cell viability, morphology, clonogenic potential, oxidative stress as measurement of reactive oxygen species (ROS) and nitric oxide (NO) levels, cytokines quantification interleukin 6 (IL-6) and tumor necrosis factor (TNF), NP uptake, and cell death. The size of Fe₃O₄ NP was 26.3 nm when evaluated in water through DLS. Fe₃O₄ NP did not reduce fibroblast cell viability until the highest concentration tested (250 µg/ml), which showed a decrease in clonogenic potential as well as small morphological changes after exposure for 48 and 72 hr. The NP concentration of 250 µg/ml induced enhanced ROS and NO production after 24 hr treatment. The uptake assay exhibited time-dependent Fe₃O₄ NP internalization at all concentrations tested with no significant cell death. Hence, exposure of fibroblasts to Fe₃O₄ NP-induced oxidative stress but not reduced cell viability or death. However, the decrease in the clonogenic potential at the highest concentration demonstrates cytotoxic effects attributed to Fe₃O₄ NP which occurred on the 7^th day after exposure.

KEYWORDS:

• Nanotoxicology
• SPION
• mixed iron oxide nanoparticle
• cytotoxicity
• murine fibroblasts LA-9

Highlights

• New Fe₃O₄ NP with sodium sulfonate ligands of interest in the oil industry.

• Cytotoxicity against fibroblasts LA-9 never evaluated before against Fe₃O₄ NP.

• Significant increase in ROS, NO and possible cell senescence process.

• Importance of furthermore in vitro studies to assess the cytotoxicity of Fe₃O₄ NP in longer periods after exposure.

Acknowledgments

We thank Doctor Márcia Regina Cominetti (Department of Gerontology, UFSCar) for the cytometer available for our analysis, Doctor Iran Malavazi (Department of Genetics and Evolution, UFSCar) for all his help in obtaining the images by SEM-FEG, Doctor Eduardo Henrique Martins Nunes and M.Sc. Himad Ahmed Alcamand (Department of Metallurgical and Materials Engineering, UFMG) for the help in our analysis ATR-FTIR.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data Availability Statement

The data that support the findings of this study are available from the corresponding author, [K.A.F], upon reasonable request. Data available at https://drive.google.com/drive/folders/1YgRjJlGHR-D0Ixe82EKfA4YMyzj-0HsQ.

Additional information

Funding

This work was supported by Leopoldo Américo Miguez de Mello Research Center CENPES/ Petrobras /Project: Proc. No 2017/00010-7.