To-Do and Not-To-Do in Model Studies of the Uptake, Fate and Metabolism of Metal-Containing Nanoparticles in Plants

Abstract

Due to the increasing release of metal-containing nanoparticles into the environment, the investigation of their interactions with plants has become a hot topic for many research fields. However, the obtention of reliable data requires a careful design of experimental model studies. The behavior of nanoparticles has to be comprehensively investigated; their stability in growth media, bioaccumulation and characterization of their physicochemical forms taken-up by plants, identification of the species created following their dissolution/oxidation, and finally, their localization within plant tissues. On the basis of their strong expertise, the authors present guidelines for studies of interactions between metal-containing nanoparticles and plants.

Phytotoxicity of Silver Nanoparticles on Tobacco Plants: Evaluation of Coating Effects on Photosynthetic Performance and Chloroplast Ultrastructure

“…Furthermore, the characteristics of AgNPs such as size, concentration, and charge [ 18 , 19 ] as well as the experimental conditions including duration and method of exposure [ 20 , 21 , 22 ] also play significant roles, influencing the stability of AgNPs and their susceptibility to transformation [ 19 , 23 ]. In recent studies, it was revealed that AgNP stability is also dependent on the composition and type of the exposure medium [ 24 , 25 ]. The use of various surface coatings in their synthesis influences the physiochemical properties of AgNPs, not only by reducing particle agglomeration and enhancing their stability but also by modulating toxic effects [ 4 , 18 , 26 , 27 ].…”

Determination of metallic nanoparticles in biological samples by single particle ICP-MS: a systematic review from sample collection to analysis

“…A low pH media (e.g., pH 5.5 and lower) should be used with caution as the acidity causes dissolution of ENMs such as Ag, ZnO and CuO. 44 Wojcieszek, et al 45 provide some useful guidance on best practices for studies investigating metal ENM uptake in plants, including on how to prepare and perform spICP-MS. A typical protocol (Table 2) with this enzyme mixture for the extraction of ENMs will involve: (i) homogenization of leaf, shoot or root tissue in a buffer solution (pH 3.5-7), (ii) addition of macerozyme R-10 enzyme solution resulting in a final volume and enzyme concentration of 1-50 mL and 1-50 mg mL −1 respectively, and (iii) incubation for 24-36 hours at 37 °C. As above, the enzyme solutions used were reported as mass concentrations of powder used as opposed to enzyme activity.…”

Nanoforms of essential metals: from hormetic phytoeffects to agricultural potential

“…In the past, the detection of nanomaterials in plant tissues provided contradictory results, partly due to the different detection techniques, nanomaterial transformation processes, nanomaterial sizes and properties, and experimental designs used in studies ( Montes et al , 2017 ; Wojcieszek et al , 2020 ). Nowadays, numerous methods are being used in nanomaterials research, which will be summarized briefly below.…”

“…The technique is limited due to the sample preparation method, since it can measure metal content only from acid-decomposed samples. A new technique, single-particle ICP-MS, has been developed, which is able to measure dissolved particles, and can measure each NP individually ( Wojcieszek et al , 2020 ). It is able to detect NP alterations, which is crucial information in samples.…”

“…It is able to detect NP alterations, which is crucial information in samples. Imaging methods used in visualizing the uptake and localization of nanomaterials in tissues include transmission and scanning electron microscopy (TEM and SEM), matrix-assisted laser desorption ionization (MALDI), and laser ablation (LA) ICP-MS ( Montes et al , 2017 ; Wojcieszek et al , 2020 ). The most prevalent technique is TEM, which can provide information about the localization, size, and aggregation of nanomaterials in cells.…”