Toxicology assessment of manganese oxide nanomaterials with enhanced electrochemical properties using human in vitro models representing different exposure routes

Abstract

In the present study, a comparative human toxicity assessment between newly developed Mn3O4 nanoparticles with enhanced electrochemical properties (GNA35) and their precursor material (Mn3O4) was performed, employing different in vitro cellular models representing alveolar, oral and dermal exposure routes, namely the human alveolar carcinoma epithelial cell line (A549), the human colorectal adenocarcinoma cell line (HT29), and the reconstructed 3D human epidermal model EpiDerm™ (RhE). The obtained results showed that Mn3O4 and GNA35 harbour similar morphological characteristics, while differences were observed in relation to their thermal stability and electrochemical properties. In regard to their toxicological properties, both nanomaterials induced oxidative stress in the A549 and HT29 cell lines that have demonstrated that manganese oxide nanoparticles reduce the cell viability in A549 cells while they do not produce any negative effect on that of HT29 cells. On the other hand, it was observed that Mn3O4 and GNA35 induce oxidative stress in both cell lines. Finally, it was noticed that none of the nanoparticles caused a reduction of the viability on the skin tissue so that they could not be classified as irritants. Our findings demonstrate that the evaluation of the toxicity of nanoparticles using different models is a critical aspect to increase the knowledge on their potential impact on human health.

Toxicological assessment of pristine and degraded forms of graphene functionalized with MnOx nanoparticles using human in vitro models representing different exposure routes

“…Moreover, testing degraded materials has also important considerations for waste management, where potential health security policies may be needed to protect workers. We realised that the induced ROS response is significantly higher when cells are exposed to GNA15 when compared to G2, as mentioned earlier, and this is probably related to the presence of MnOx-NPs in GNA15, due to the strong oxidative stress-inducing properties of this metal oxide 43 . High oxidative stress is contributing to the cytotoxicity provoked by NPs, especially for metal oxide particles such as TiO 2 , ZnO, Co 3 O 4 , and CuO 52 , 53 .…”

“…2 ). On the other hand, significant morphological differences were observed between GNA15 and manganese oxide NPs, showing the last ones have round shape 43 . Raman analysis confirmed the structural changes after the ultrasonication, showing that the degraded NMs have a higher degree of exfoliation than their original forms (Fig.…”

“…Fernández-Pampín et al showed that Mn 3 O 4 NPs provoke the ROS generation in A549 and HT-29 cell lines. 43 Moreover, a recent study by Stygar et al 55 determined the toxicity of GO in comparison with an Mn 2+ contaminated GO over human dermal fibroblasts and A549 cells. By measuring selected oxidative stress markers, the authors reported that GO induced a lower oxidative stress response in comparison with the contaminated NM, but none of the materials caused the cellular collapse.…”

“…The method 23 was adapted for human cell lines by Fernández-Pampín et al 30 , 43 , and quantitatively measures ROS in cells exposed to NMs. We seeded A549 and HT-29 cells in 96 micro-well plates, at a density of 3 × 10 4 cells per well.…”

Manganese Oxide Nanoparticles: An Insight into Structure, Synthesis and Applications

“…Limiting manganese oxide NPs' ability to dissolve might be one of the potential solutions. Development of nanomaterials with the appropriate properties and high biocompatibility would be possible with careful adjustments to the size and surface properties of manganese oxide nanoparticles [145][146][147].…”