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Interaction of silver nanoparticles with algal and fish cells

 

Silver in the form of nanoparticles is increasingly used in industry and medicine. The experiments carried out by Kristin Schirmer and her team show that fish cells absorb silver nanoparticles, whereas algal cells capture the particles in their outer cell wall structures. Regardless of whether the particles are absorbed or not, they can bind to proteins and interfere with the function of these proteins.

Background (completed research project)

Silver has an anti-microbial effect and is used in numerous consumer and medical products in the form of nanoparticles. The number of products containing nanosilver is growing rapidly, and the amount of nanosilver ending in the environment is increasing accordingly. Kristin Schirmer and her team examined the environmental impact of nanosilver on vegetal and animal aquatic organisms. In algal cells, which are surrounded by a cell wall, and fish cells, which do not have a cell wall, the team examined whether nanosilver is absorbed into the cells and how the nanoparticles interact with proteins inside the cells and in the immediate vicinity of the cells. The researchers also examined whether silver ions, which can be released by silver nanoparticles, have a toxic effect on algal cells or fish cells.

Results

The experiments showed that nanosilver can affect central functions, both in algal and fish cells and therefore may have a toxic effect. The mechanisms by which the silver nanoparticles act on the cells, however, are different for algal and fish cells. Whereas algal cells are unable to absorb the silver nanoparticles, fish cells have specific transport mechanisms, which enable the nanoparticles to pass through the cell membrane to the interior of the cells. Kristin Schirmer and her team were able to demonstrate that nanoparticles interact with proteins both inside and outside of the cells. In the case of algael cells, they bind to proteins, which are excreted by the algae to decompose food. In fish cells, the nanoparticles also bind inside the cell to hundreds of proteins that accumulate around the nanoparticles as so-called protein corona. The researchers were able to identify the individual proteins of the protein corona and show that this provides important information about how the toxic effects of nanoparticles arise. In the case of both the algal and fish cells, the researchers discovered harmful effects that can be attributed to the silver ions released by the silver nanoparticles.

Relevance

The project indicates the dynamics and identifies different mechanisms by which the silver nanoparticles interact with plant and animal cells. This understanding is essential for correctly assessing the risks associated with the release of nanosilver into the environment and forms a basis for ensuring the environmentally sound application of nanoparticles in industry and medicine.

Original title

Interaction of metal nanoparticles with aquatic organisms (MeNanoqa)

Project leader(s)

  • Prof. Kristin Schirmer

Co-applicants

  • Dr. Renata Behra
  • Prof. Laura Sigg
  • Dr. Marc Suter

 

 

Further information on this content

 Contact

Prof. Kristin Schirmer Umwelttoxikologie UTOX
EAWAG
Überlandstrasse 133 8600 Dübendorf +41 44 823 52 66 kristin.schirmer@eawag.ch