Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Realistic exposure study supports the use of zinc oxide nanoparticle sunscreens

05.12.2018

New risk assessment may help allay safety concerns, according to an important study conducted in Australia, reported in the Journal of Investigative Dermatology

Zinc oxide (ZnO) has long been recognized as an effective sunscreen agent. However, there have been calls for sunscreens containing ZnO nanoparticles to be banned because of potential toxicity and the need for caution in the absence of safety data in humans.


Multiphoton images of human skin at a depth of 15-20 μm below the skin surface in volunteers after application of uncoated and silicone-coated zinc oxide nanoparticles suspended in a commercial sunscreen base compared with no product (untreated control). Red and yellow pseudocolor indicates the presence of zinc oxide nanoparticles in skin furrows. The blue-green color shows autofluorescence from living epidermal cells, with no evidence of zinc oxide nanoparticle penetration.

Credit: Journal of Investigative Dermatology

An important new study provides the first direct evidence that intact ZnO nanoparticles neither penetrate the human skin barrier nor cause cellular toxicity after repeated application to human volunteers under in-use conditions.

This confirms that the known benefits of using ZnO nanoparticles in sunscreens clearly outweigh the perceived risks, reports the Journal of Investigative Dermatology.

The safety of nanoparticles used in sunscreens has been a highly controversial international issue in recent years, as previous animal exposure studies found much higher skin absorption of zinc from application of ZnO sunscreens to the skin than in human studies.

Some public advocacy groups have voiced concern that penetration of the upper layer of the skin by sunscreens containing ZnO nanoparticles could gain access to the living cells in the viable epidermis with toxic consequences, including DNA damage.

A potential danger, therefore, is that this concern may also result in an undesirable downturn in sunscreen use. A 2017 National Sun Protection Survey by the Cancer Council Australia found only 55 percent of Australians believed it was safe to use sunscreen every day, down from 61 per cent in 2014.

Investigators in Australia studied the safety of repeated application of agglomerated ZnO nanoparticles applied to five human volunteers (aged 20 to 30 years) over five days. This mimics normal product use by consumers. They applied ZnO nanoparticles suspended in a commercial sunscreen base to the skin of volunteers hourly for six hours and daily for five days.

Using multiphoton tomography with fluorescence lifetime imaging microscopy, they showed that the nanoparticles remained within the superficial layers of the stratum corneum and in the skin furrows. The fate of ZnO nanoparticles was also characterized in excised human skin in vitro. They did not penetrate the viable epidermis and no cellular toxicity was seen, even after repeated hourly or daily applications typically used for sunscreens.

"The terrible consequences of skin cancer and photoaging are much greater than any toxicity risk posed by approved sunscreens," stated lead investigator Michael S. Roberts, PhD, of the Therapeutics Research Centre, The University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, and School of Pharmacy and Medical Sciences, University of South Australia, Sansom Institute, Adelaide, QLD, Australia.

"This study has shown that sunscreens containing nano ZnO can be repeatedly applied to the skin with minimal risk of any toxicity. We hope that these findings will help improve consumer confidence in these products, and in turn lead to better sun protection and reduction in ultraviolet-induced skin aging and cancer cases," he concluded.

"This study reinforces the important public health message that the known benefits of using ZnO nano sunscreens clearly outweigh the perceived risks of using nano sunscreens that are not supported by the scientific evidence," commented Paul F.A. Wright, PhD, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia, in an accompanying editorial.

"Of great significance is the investigators' finding that the slight increase in zinc ion concentrations in viable epidermis was not associated with cellular toxicity under conditions of realistic ZnO nano sunscreen use.

Media Contact

Helen Habernickel
hmsmedia@elsevier.com
49-306-449-20374

 @elseviernews

http://www.elsevier.com 

Helen Habernickel | EurekAlert!
Further information:
https://www.elsevier.com/about/press-releases/research-and-journals/realistic-exposure-study-supports-the-use-of-zinc-oxide-nanoparticle-sunscreens
http://dx.doi.org/10.1016/j.jid.2018.08.024

Further reports about: Nanoparticles ZnO human skin nanoparticle skin sunscreen toxicity zinc

More articles from Materials Sciences:

nachricht Crystal with a twist: Scientists grow spiraling new material
21.06.2019 | University of California - Berkeley

nachricht A new manufacturing process for aluminum alloys
19.06.2019 | DOE/Pacific Northwest National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer IDMT demonstrates its method for acoustic quality inspection at »Sensor+Test 2019« in Nürnberg

From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.

Reducing machine downtime, manufacturing defects, and excessive scrap

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

'Sneezing' plants contribute to disease proliferation

24.06.2019 | Agricultural and Forestry Science

Researchers find new mutation in the leptin gene

24.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>