Ecological Risks of Nanoparticles
| Autor: | Praveen Kumar, R. K. Kaul, Uday Burman |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Reactive oxygen species Metal ions in aqueous solution technology industry and agriculture Oxide Nanoparticle 02 engineering and technology 010501 environmental sciences 021001 nanoscience & nanotechnology Endocytosis 01 natural sciences Nanomaterials Metal chemistry.chemical_compound Membrane chemistry visual_art visual_art.visual_art_medium Biophysics 0210 nano-technology health care economics and organizations 0105 earth and related environmental sciences |
| Popis: | A large part of the more than 11 million tons of nanomaterials produced every year are metal and metal oxide nanoparticles (NPs), which ultimately end up in soil. NPs could enter into microbial cells either through endocytosis or by penetrating cells, and many of them, especially silver, copper, and zinc, have antimicrobial properties. Thus after entering the soil, NPs could adversely affect microorganisms present and disrupt essential functions of the soil. The effect of NPs on microorganisms and the mechanisms of their toxicity are comprehensively reviewed and discussed in this chapter. Both physical characteristics and chemical interactions of NPs at the nano–bio interface could elicit toxic effects, depending on their physical structure and chemical composition. Physical interactions, depending on size and surface properties of NPs at the nano–bio interface, could cause membrane disintegration and interference in transport processes. NPs, which are the same size as a protein molecule, interact with proteins and change their configuration, thus obstructing signaling processes in cells. Their shape can also affect toxicity by influencing uptake efficiency (rod-shaped NPs show maximum uptake and cubes minimum uptake), subsequently causing physical disintegration of membranes (truncated triangular silver nanoplates display the strongest biocidal action against Escherichia coli ). Once inside the cells, NPs affect the catalytic activity of enzymes and stability of protein structures. Release of metal ions and the generation of reactive oxygen species restrict normal physiological redox-regulated functions of cells and lead to oxidative modification of proteins, which causes mortality of cells. Carbon-based NPs are less toxic than metal or metal oxide NPs but generation of reactive oxygen remains a major mechanism behind their toxicity. |
| Databáze: | OpenAIRE |
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