Tag Archives: University of Southern Denmark

Nanoparticles in combination could be more toxic

It seems that one set of nanoparticles, e.g., silver nanoparticles, in combination with another material, e.g., cadmium ions, are more dangerous than either one separately according to an August 17, 2018 University of Southern Denmark press release by Birgitte Svennevig (also on EurekAlert but dated August 20, 2018),

Researchers warn that a combination of nanoparticles and contaminants may form a cocktail that is harmful to our cells. In their study, 72 pct. of cells died after exposure to a cocktail of nano-silver and cadmium ions.

Nanoparticles are becoming increasingly widespread in our environment. Thousands of products contain nanoparticles because of their unique properties. Silver nanoparticles are one example: They have an effective antibacterial effect and can be found in refrigerators, sports clothes, cosmetics, tooth brushes, water filters, etc.

There is a significant difference between how the cells react when exposed to nanosilver alone and when they are exposed to a cocktail of nanosilver and cadmium ions. Cadmium ions are naturally found everywhere around us on Earth.

In the study, 72 pct. of the cells died, when exposed to both nanosilver and cadmiun ions. When exposed to nanosilver only, 25 pct. died. When exposed to cadmium ions only, 12 pct. died.

The study was conducted on human liver cancer cells.

  • This study indicates, that we should not look at nanoparticles isolated when we investigate and discuss the effects, they may have on our health. We need to take cocktail effects into account, said Professor Frank Kjeldsen, Dept of Biochemistry and Molecular Biology, SDU, adding:
  • Products with nano particles are being developed and manufactured every day, but in most countries there are no regulations, so there is no way of knowing what and how many nanoparticles are being released into the environment. In my opinion, this should be stopped.

Other studies, led by Professor Kjeldsen have previously shown that human cells interact with metal nanoparticles.

One study showed that nano-silver leads to the formation free radicals in cells and changes in the form and amount of proteins. Many serious diseases are characterized by an overproduction of free radicals in cells. This applies to cancer and neurological diseases such as Alzheimer’s and Parkinson’s.

This is not great news but there are a few things to note about this research. First, it was conducted on cells and therefore not subject to some of the defensive systems found in complete biological organisms such as a mouse or a dandelion plant for example.

Also, since they were cancer cells one might suspect their reactions might differ from those of healthy cells. As for how the cells were exposed to the contaminants, I think (???) they were sitting in a solution of contaminants and most of us do not live in that kind of environment.. Finally, with regard to the concentrations, I have no idea if they are greater than one might expect to encounter in one’s lifecycle but it’s always worth questioning just how much exposure you might expect during yours or a mouse’s or a dandelion’s life.

These caveats aside, Professor Frank Kjeldsen’s work raises some very concerning issues and his work adds to a growing body of evidence.

Here’s a video featuring Dr. Kjeldsen talking about his work,

Here’s a link to and a citation for the paper,

Co-exposure to silver nanoparticles and cadmium induce metabolic adaptation in HepG2 cells by Renata Rank Miranda, Vladimir Gorshkov, Barbara Korzeniowska, Stefan J. Kempf, Francisco Filipak Neto, & Frank Kjeldsen. Nanotoxicology DOI: https://doi.org/10.1080/17435390.2018.1489987 Published online: 11 Jul 2018

This paper is open access.

Danish scientists provide insights into celllular response to silver nanoparticles

The conclusions are concerning but the scientists at the University of Southern Denmark are careful to note that this research on silver nanopartices was performed in a laboratory setting which does not necessarily predict what might happen under real life conditions.

As for the research itself, a Feb. 28, 2014 news item on Azonano has this to say,

Endocrine disrupters are not the only worrying chemicals that ordinary consumers are exposed to in everyday life. Also nanoparticles of silver, found in e.g. dietary supplements, cosmetics and food packaging, now worry scientists. A new study from the University of Southern Denmark shows that nano-silver can penetrate our cells and cause damage.

Silver has an antibacterial effect and therefore the food and cosmetic industry often coat their products with silver nanoparticles. Nano-silver can be found in e.g. drinking bottles, cosmetics, band aids, toothbrushes, running socks, refrigerators, washing machines and food packagings.

“Silver as a metal does not pose any danger, but when you break it down to nano-sizes, the particles become small enough to penetrate a cell wall. If nano-silver enters a human cell, it can cause changes in the cell”, explain Associate Professor Frank Kjeldsen and PhD Thiago Verano-Braga, Department of Biochemistry and Molecular Biology at the University of Southern Denmark.

A Feb. 27, 2014 University of Southern Denmark news release, which originated the news item, provides more detail about the research,

The researchers examined human intestinal cells, as they consider these to be most likely to come into contact with nano-silver, ingested with food.

“We can confirm that nano-silver leads to the formation of harmful, so called free radicals in cells. We can also see that there are changes in the form and amount of proteins. This worries us”, say Frank Kjeldsen and Thiago Verano-Braga.

A large number of serious diseases are characterized by the fact that there is an overproduction of free radicals in cells. This applies to cancer and neurological diseases such as Alzheimer’s and Parkinson’s.

Kjeldsen and Verano-Braga emphasizes that their research is conducted on human cells in a laboratory, not based on living people. They also point out that they do not know how large a dose of nano-silver, a person must be exposed to for the emergence of cellular changes.

“We don’t know how much is needed, so we cannot conclude that nano-silver can make you sick. But we can say that we must be very cautious and worried when we see an overproduction of free radicals in human cells”, they say.

Nano-silver is also sold as a dietary supplement, promising to have an antibacterial, anti-flu and cancer-inhibatory effect. The nano-silver should also help against low blood counts and bad skin. In the EU, the marketing of dietary supplements and foods with claims to have medical effects is not allowed. But the nano-silver is easy to find and buy online.

In the wake of the SDU-research, the Danish Veterinary and Food Administration now warns against taking dietary supplements with nano-silver.

“The recent research strongly suggests that it can be dangerous”, says Søren Langkilde from the Danish Veterinary and Food Administration to the Danish Broadcasting Corporation (DR).

The researchers supplied this image to illustrate the abstract for their paper (link and citation to follow),

Courtesy University of Southern Denmark

Courtesy University of Southern Denmark

Here’s a link to and a citation for the research paper,

Insights into the Cellular Response Triggered by Silver Nanoparticles Using Quantitative Proteomics by Thiago Verano-Braga, Rona Miethling-Graff, Katarzyna Wojdyla, Adelina Rogowska-Wrzesinska, Jonathan R. Brewer, Helmut Erdmann, and Frank Kjeldsen. ACS Nano, Article ASAP DOI: 10.1021/nn4050744 Publication Date (Web): February 10, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.