Home > Press > Tracking down the effect of nanoparticles
|Cell cultures of lung epithelial cells (in the right-hand box) were exposed to an aerosol of cerium oxide nanoparticles in a special glove box. During the exposure of the cell cultures, the nanoparticles were freshly produced by flame synthesis in the left half of the box. |
Cerium oxide is a ceramic nano-abrasive. Scientists have now examined, under conditions close to reality, what happens when it is breathed in and deposited on the lung surface. Initially, the result was rather reassuring.
Tracking down the effect of nanoparticles
Zurich, Switzerland | Posted on April 12th, 2009
Synthetic nanoparticles are ubiquitous nowadays: either as an additive to building materials, whose properties they improve; in cosmetics, mainly in sun creams and toothpaste; or in foodstuffs, to thicken them or brighten their color. However, nano-safety research, i.e. knowledge of how nanoparticles interact with their environment and specifically with a living organism, is still largely in its infancy.
However, this is one of the central topics for the research group led by Wendelin Stark, Assistant Professor at the Institute for Chemical and Bio-engineering of ETH Zurich. The group carries out tests over and over again to investigate the effect nanoparticles have on their surroundings (see the ETH Life article of 15.07.2008)
Conditions close to reality
Together with the research group led by Peter Gehr, Professor of Histology at the University of Bern, the scientists have now used a completely new method and a new type of lung cell culture to examine how cerium oxide nanoparticles act on the cells. The aim was to study the toxicity of cerium oxide, which is used in large amounts as an abrasive, mainly in the manufacture of semiconductor chips. Although, as a rule, this takes place in a hermetically sealed room from which people are excluded, the researchers now simulated a situation in which ceramic nanomaterial is inhaled directly, for example if nanoparticles are manufactured without protection or the powder is handled incorrectly.
The researchers did this by using what is called flame spray synthesis to spray cerium oxide nanoparticles in a closed glove box, thus simulating aerosols. A fan distributed the aerosols uniformly in the box, about 2.5 cubic meters in size, in which the aerosols were sprayed on to the cultured lung cells for ten, twenty and thirty minutes. The ETH researches hit upon the idea when they spoke to Barbara Rothen-Rutishauser, a scientist from Bern and first author of the paper. She told them about the new type of cell culture. The results of the interdisciplinary collaboration were published on-line in "Environmental Science and Technology".
The innovative aspect of the method is the special cell culture combined with the use of flame spray synthesis. The cell culture of lung epithelial cells grows on a permeable membrane. The lower surface of the epithelial cells is immersed in a medium and their upper surface is covered with a natural liquid layer. Thus the cell culture is very similar to the surface of the lung. As a result of the aerosol production, the spray process is also close to reality. The combination of these two techniques showed how inhaled nanoparticles are deposited on the lung surface. In conventional methods for such experiments up to now, cell cultures were bathed in nanoparticle solutions. However, this can cause the nanoparticles to agglomerate, which alters their properties; moreover, the lung surface is wet in a different way. Consequently, the behavior of the cells might also change.
No cell death
The scientists chose cerium oxide for their study, mainly because the material does not occur physiologically in cells, meaning that only the effect of the nanoparticle on the cell is observed. The longer the cultures were sprayed for, the more nanoparticles were deposited on the lung cells. The scientists observed that the cells were not destroyed, i.e. they did not die. However, the permeability of the cell layer increased. Therefore, the researchers suspect that certain structures of particular proteins that seal the interstices between the epithelial cells had altered under the influence of the nanoparticles. The production of a substance in the cell which is associated with oxidative stress and which could result in DNA damage could also be observed.
Long-term effects unknown
Robert Grass, group leader in Wendelin Stark's group, explains: "However, we were unable to observe the effect of the particles on the cells over a prolonged time." This is because the cultures must be subjected to further processing to allow them to be examined under a microscope. In a next step, the researchers plan to replicate even more realistic conditions by using what are known as triple cell co-cultures that simulate human cellular respiratory tract barriers. For example, they want to find out how the body's phagocytes and "waste disposal agents", known as macrophages, deal with nanoparticles.
Author: Simone Ulmer
Rothen-Rutishauser B, Grass RN, Blank F, Limbach LK, Mühlfeld C, Brandenberger C, Raemy DO, Gehr P & Stark WJ: Direct Combination of Nanoparticle Fabrication and Exposure to Lung Cell Cultures in a Closed Setup as a Method To Simulate Accidental Nanoparticle Exposure of Humans, Environ. Sci. Technol., On-line publication 2 March 2009 DOI: 10.1021/es8029347
About ETH Zurich
ETH Zurich is an institution of the Swiss Confederation dedicated to higher learning and research. Together with the ETH Lausanne and four research institutes, it forms the federally directed, and to a major degree financed, ETH domain. The institutions of the ETH domain uphold their autonomy and identity on the basis of the ETH Federal Law and in the full awareness of their social, economic and cultural responsibility to the nation and its citizens.
For more information, please click here
HG F 41
Fax +41 44 632 17 16
Copyright © ETH Zurich
If you have a comment, please Contact
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
News and information
Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014
President Obama Meets U.S. Laureates of 2014 Kavli Prizes August 1st, 2014
Stanford researchers seek 'Holy Grail' in battery design: Pure lithium anode closer to reality with development of protective layer of interconnected carbon domes August 1st, 2014
Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014
INSCX™ exchange launches upgraded Physical Trade Platform December 7th, 2012
Iran's Nanotechnology Capabilities Displayed in Russia Open Innovations Expo 2012 November 10th, 2012
Application of Adamantane November 7th, 2012
SWR&D Purchases NanoBioMagnetics August 1st, 2012
Preparing for Nano
Durnham University's DEEPEN project comes to a close September 26th, 2012
Technical Seminar at ANFoS 2012 August 22nd, 2012
Nanotechnology shows we can innovate without economic growth April 12th, 2012
Thailand to host NanoThailand 2012 December 18th, 2011
Iranian Scientists Produce Reusable Nanoadsorbent to Detect Sulfamide in Chicken July 27th, 2014
Key Announcements made at TAPPI International Nanotechnology Conference July 7th, 2014
Squid sucker ring teeth material could aid reconstructive surgery, serve as eco-packaging July 2nd, 2014
FDA issues guidance on use of nanotechnology in foods July 1st, 2014
Nanostructured metal-oxide catalyst efficiently converts CO2 to methanol: Highly reactive sites at interface of 2 nanoscale components could help overcome hurdle of using CO2 as a starting point in producing useful products July 31st, 2014
University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014
FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 2014
Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014
Nanotechnology used in sunscreens: a Mexican achievement May 14th, 2014
Production of Nanocapsule from Sea-Buckthorn Extract in Iran May 3rd, 2014
Good vibrations: Using light-heated water to deliver drugs - Researchers use near-infrared light to warm water-infused polymeric particles April 1st, 2014
Iranian Food Industry Utilizes Lipid Nanocarriers for Beta-Carotene Enrichment January 23rd, 2014
Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014
NNCO Announces an Interactive Webinar: Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy July 23rd, 2014
Development of an interactive tool for the implementation of environmental legislation for nanoparticles manufacturers July 4th, 2014
FDA issues guidance on use of nanotechnology in foods July 1st, 2014