Advanced materials comprising multiple metal alloys have made their way into the market. Trimetal-based nanomaterials (TNMs) are an example of advanced materials which have gained significant... Show moreAdvanced materials comprising multiple metal alloys have made their way into the market. Trimetal-based nanomaterials (TNMs) are an example of advanced materials which have gained significant traction and are now employed in a wide array of products. It is essential to raise the question if the toxicity of advanced nanomaterials like TNMs differs from the joint effects as manifested by exposure to the single component nanoparticles (NPs). To answer this question, a trimetal-based nanomaterial: bismuth cobalt zinc oxide (BiCoZnO) was tested. This TNM had a mass ratio of 90 % ZnO NPs, 7 % Bi2O3 NPs and 3 % Co3O4 NPs. Nanoparticle-exposed lettuce seedlings (Lactuca sativa L.) showed decreases in relative root elongation (RRE) and biomass production after 21 days of exposure. The 50 % of maximal effective concentration (EC50) value of the TNMs for biomass production was 1.2 mg L− 1 when the exposure period was 240 h. This is of the same magnitude as the EC50 values found for ZnO NPs (EC50 = 1.5 mg L− 1 ) and for the mixture of components NPs (MCNPs) which jointly form the TNMs (EC50 = 3.7 mg L− 1 ) after 10 d of exposure. The inhibition of plant root elongation by the TNMs was partially (65 %) attributed to the release of Zn ions, with the actual concentration of released Zn ions being lower in TNMs compared to the actual concentration of Zn ions in case of ZnO NPs. It is therefore to be concluded that the concentration of Zn ions cannot be used as a direct measure to compare the toxicity between traditional and advanced Zn-related nanomaterials. The EC50 values could be assessed within a factor of two; which is helpful when developing advanced alloy nanomaterials and assessing prospective the effects of trimetal-based nanomaterials. Show less
Novel entities may pose risks to humans and the environment. The small particle size and relatively large surface area of micro- and nanoparticles (MNPs) make them capable of adsorbing other novel... Show moreNovel entities may pose risks to humans and the environment. The small particle size and relatively large surface area of micro- and nanoparticles (MNPs) make them capable of adsorbing other novel entities, leading to the formation of aggregated contamination. In this dissertation, we utilized advanced computational methods, such as molecular simulation, data mining, machine learning, and quantitative structure-activity relationship modeling. These methods were used to investigate the mechanisms of interaction between MNPs and other novel entities, the joint toxic action of MNPs and other novel entities, the factors affecting their joint toxicity to ecological species, as well as to quantitatively predict the interaction forces between MNPs and other novel entities, and the toxicity of their mixtures. The results indicate that understanding the mechanisms of interactions between novel entities and their modes of joint toxic action can provide an important theoretical basis for establishing effective risk assessment procedures to mitigate the effects of novel entities on ecosystems and human health. Furthermore, this dissertation provides important technical support and a practical basis for the quantitative prediction of the environmental behavior and toxicological effects of novel entities and their mixtures by applying various advanced in silico methods individually or in combination. Show less
The major and ultimate aim of metabolomics is to obtain an answer to a specific biological or clinical question. For that, many strategies have been applied in this field, including NMR and MS... Show moreThe major and ultimate aim of metabolomics is to obtain an answer to a specific biological or clinical question. For that, many strategies have been applied in this field, including NMR and MS-based approaches. CE-MS is one of the techniques in this field but remains underappreciated because of issues such as compromised sensitivity and poor reproducibility. In this thesis, we proposed standardized protocols for CE-MS studies using a sheathless interface and applied them in the metabolic analysis of ultra-small biological samples, such as low numbers of HepG2 cells. Another CE-MS technique used in this thesis is the traditional sheath liquid CE-MS, and it was successfully used in the metabolic profiling of plasma samples. We also introduced CE-MS with both interfaces in the field of nanosciences with our efforts in revealing the adsorption characteristics of polar metabolites to the surface of nanomaterials. This work clearly demonstrates that CE-MS can be reliably performed for metabolomics studies with acceptable repeatability. The use of sheathless CE-MS interface enables us to have in-depth profiling for ultra-small samples, and may become a powerful tool in the emerging field of single-cell analysis. Show less
