In a wide variety of products and production processes, nanoparticles are used because when the material falls down in nano form, the properties of a material will change drastically.
For example, they can be used to purify waste water and move medication around the body. In order to provide the products with an antibacterial surface, they are often attached to socks, pillows, mattresses, phone covers and refrigerators, for example.
There has been a lot of research on how nanoparticles impact humans and the environment, and a variety of studies have shown that our cells can be disturbed or impaired by nanoparticles.
This is supported by a recent study that also looked at how cells react at the same time when they are exposed to more than one form of nano particle.
Barbara Korzeniowska of the Department of Biochemistry and Molecular Biology at SDU is the lead author of the research. Professor Frank Kjeldsen, from the same department, is the head of science.
A European Research Grant of DKK 14 million funds his research into metal nanoparticles.
“We are exposed to several different kinds of nano-particles over a lifetime, and we should investigate how we are influenced by the combination of different nano-particles and whether aggregation over life can damage us,” says Barbara Korzeniowska.
When her little daughter went into the bathtub one day and got a rubber duck as a toy, she herself became interested in the subject.
“It turned out that nano-silver was treated, presumably to keep it free of bacteria, but small children put their toys in their mouths, so they could consume nano-silver. This is extremely troubling because evidence shows that human cells can be harmed by nano-silver,” she says.
She looked at nano-silver and nano-platinum in her latest survey. She has researched their individual effects and whether exposure to both types of nanoparticles results in two types of brain cells having a synergistic impact.
“Nearly no synergy impact studies of nano particles have been performed, so it is important to get started with these studies,” she says.
She chose nano-silver because it is already recognized that cells and nano-platinum can be damaged, because nano-platinum is considered to be bio-inert; that is, it has limited contact with human tissue.
Two types of brain cells were tested on the nanoparticles: astrocytes and endothelial cells. In the central nervous system, astrocytes are protective cells, i.a. It helps to provide nutrients to the nervous system and restore damage to the brain. On the inside of the blood vessels, endothelial cells sit and bring substances from the bloodstream to the brain.
Nothing occurred when the endothelial cells were exposed to nano-platinum. Their ability to separate decreased when they were exposed to nano-silver. The effect was exacerbated when both nano-silver and nano-platinum were revealed, and they died in great numbers. In addition, their defensive mechanisms were diminishing, and they had trouble interacting with each other.
“Thus, even though nano-platinum alone does no harm, when combined with a different form of nano-particle, something dramatic happens,” says Frank Kjeldsen.
The astrocytes were more resistant and responded “only” when exposed to both forms of nano-particles, with impaired ability to divide.
An earlier study by Frank Kjeldsen showed that silver nanoparticles and cadmium ions, which are naturally found all around us on Earth, have a dramatic synergy effect. In that study, 72 percent of the cells died as they were exposed to both nano-silver and cadmium ions (in this study it was intestinal cells). 25 per cent died because they were just exposed to nano-silver. 12 percent died when exposed to cadmium ions alone.
We are exposed involuntarily
“In industrial goods, little is known about how large amounts of nano-particles are used. We also don’t know what particle size they use — size also affects whether they can penetrate a cell,” says Barbara Korzeniowska, and continues:
“But we know that a lot of people are exposed to nano-particles accidentally, and that there can be lifelong exposure.”
The addition of nanoparticles to products has practically no limitations. In the EU, however, if manufacturers wish to use nanoparticles in products with antibacterial properties, they must be licensed. In Denmark, nano-content in such items must also be declared on the label.
Source of Story: Supported by the University of Southern Denmark with materials. Written in the original by Birgitte Svennevig. Note: For style and length, material can be edited.