Zn leakage and photo-induced reactive oxidative species do not explain the full toxicity of ZnO core Quantum Dots.
Fiche publication
Date publication
avril 2020
Journal
Journal of hazardous materials
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SCHNEIDER Raphaël
Tous les auteurs :
Bellanger X, Schneider R, Dezanet C, Arroua B, Balan L, Billard P, Merlin C
Lien Pubmed
Résumé
Metal oxide nanoparticles (NPs), and among them metal oxides Quantum Dots (QDs), exhibit a multifactorial toxicity combining metal leaching, oxidative stress and possibly direct deleterious interactions, the relative contribution of each varying according to the NP composition and surface chemistry. Their wide use in public and industrial domains requires a good understanding and even a good control of their toxicity. To address this question, we engineered ZnO QDs with different surface chemistries, expecting that they would exhibit different photo-induced reactivities and possibly different levels of interaction with biological materials. No photo-induced toxicity could be detected on whole bacterial cell toxicity assays, indicating that ROS-dependent damages, albeit real, are hidden behind a stronger source of toxicity, which was comforted by the fact that the different ZnO QDs displayed the same level of cell toxicity. However, using in vitro DNA damage assays based on quantitative PCR, significant photo-induced reactivity could be measured precisely, showing that different NPs exhibiting similar inhibitory effects on whole bacteria could differ dramatically in terms of ROS-generated damages on biomolecules. We propose that direct interactions between NPs and bacterial cell surfaces prime over any kind of intracellular damages to explain the ZnO QDs toxicity on whole bacterial cells.
Mots clés
Cell surface damages, Metal oxide nanoparticles, Nanotoxicity, Photo-induced reactive oxygen species, ZnO Quantum Dots
Référence
J. Hazard. Mater.. 2020 Apr 6;396:122616