Studies on plant cell toxicity of luminescent silica nanoparticles (Cs2[Mo6Br14]@SiO2) and its constitutive components

Abstract

International audienceAs part of the risk evaluation before potential applications of nanomaterials, phytotoxicity of newly designed multifunctional silica nanoparticles (CMB@SiO2, average diameter of 47 nm) and their components, i.e., molybdenum octahedral cluster bromide units (CMB, 1 nm) and SiO2 nanoparticles (nSiO2, 29 nm), has been studied using photosynthetic Arabidopsis thaliana cell suspension cultures. CMB clusters presented toxic effects on plant cells, inhibiting cell growth and negatively affecting cell viability and photosynthetic efficiency. Nevertheless, we showed that neither nSiO2 nor CMB@SiO2 have any significant effect on cell growth and viability or photosynthetic efficiency. At least, part of the harmful impact of CMB clusters could be ascribed to their capacity to generate an oxidative stress since lipid peroxidation greatly increased after CMB exposure, which was not the case for nSiO2 or CMB@SiO2 treatments. Exposure of cells to CMB clusters also leads to the induction of several enzymatic antioxidant activities (i.e., superoxide dismutase, guaiacol peroxidase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase activities) compared to control and the other treatments. Finally, using electron microscopy, we showed that Arabidopsis cells internalize CMB clusters and both silica nanoparticles, the latter through, most likely, endocytosis-like pathway as nanoparticles were mainly found incorporated into vesicles

Formation Mechanism of Transparent Mo6Metal Atom Cluster Film Prepared by Electrophoretic Deposition

“…Cl, I at face-capping inner position) capped by 6 halogens or functional groups at the terminal apical position (L a = donor ligand; Br, Cl, I, OH, H2O, CF3COOH,…) 2,5 , has recently been studied in applications of pH-sensor 6 , singlet oxygen sensitization 7 , photocatalytic reactions 4,8 , solar cells [9][10][11] or biotechnology [12][13][14][15][16][17][18] . The synthesis of hybrid nanocomposites based on metal atom clusters has also attracted the interest in optoelectronic applications 4 , but only a few studies have reported the preparation of transparent thin films [19][20][21] .…”

“…), 2,5 has recently been studied in applications of pH-sensor, 6 singlet oxygen sensitization, 7 photocatalytic reactions, 4,8 solar cells [9][10][11] or biotechnology. [12][13][14][15][16][17][18] The synthesis of hybrid nanocomposites based on metal atom clusters has also attracted the interest in optoelectronic applications, 4 but only a few studies have reported the preparation of transparent thin films. [19][20][21] The surface of glass is often coated for intrinsic reasons (safety, convenience or better stability, etc.)…”

Zinc-Supported Multiwalled Carbon Nanotube Nanocomposite: A Synergism to Micronutrient Release and a Smart Distributor To Promote the Growth of Onion Seeds in Arid Conditions

“…These potential changes in nanomaterials leading to a change in the size, shape, or state of aggregation are due to the uptake and bioaccumulation of nanomaterials via plants and are most crucially governed by many environmental and physiochemical aspects and the nature of interaction with cell organelles. 49,50 Furthermore, to observe these ZnO/MWCNTs inside the cells, TEM of onion stem was performed (Figure 7), wherein we found that the ZnO/MWCNTs are present in subcellular organelles. Our observations corroborated the prior findings 6,51 as we noticed that ZnO/MWCNTs directly penetrated the cells as they were normally observed in the cytoplasm.…”

A review on functional nanoarchitectonics nanocomposites based on octahedral metal atom clusters (Nb 6 , Mo 6 , Ta 6 , W 6 , Re 6 ): inorganic 0D and 2D powders and films

“…[130] In opposite, Cabello-Hurtado et al showed that [{Mo 6 Br i 8 }X a 6 ]@SiO 2 have any phytotoxicity significant effect on plant cell growth and viability or photosynthetic efficiency on Arabidopsis thaliana. [125] Since this first example of 0D {[{Mo 6 X i 8 }X a 6 ]@SiO 2 (X = Cl, Br, or I) nanocomposites, some studies have been published on the synthesis of homogeneous functional silica nanocomposites based on transition metal atom cluster compounds. For the Mo 6 , this process was successfully used with the highly red-NIR luminescent new red-emitting @silica 0D nanocomposites based on A 4 [{Re 6 X i 8 }X a 6 ] metal atom clusters compounds (A = Cs or K, X i = S or Se, and X a = OH or CN) with an interesting changing in the chemical process.…”