Tag Archives: Georgia Miller

Get better protection from a sunscreen with a ‘flamenco dancing’ molecule?

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Caption: illustrative image for the University of Warwick research on ‘Flamenco dancing’ molecule could lead to better-protecting sunscreen created by Dr. Michael Horbury. Credit:: created by Dr Michael Horbury

There are high hopes (more about why later) for a plant-based ‘flamenco dancing molecule’ and its inclusion in sunscreens as described in an October 18, 2019 University of Warwick press release (also on EurekAlert),

A molecule that protects plants from overexposure to harmful sunlight thanks to its flamenco-style twist could form the basis for a new longer-lasting sunscreen, chemists at the University of Warwick have found, in collaboration with colleagues in France and Spain. Research on the green molecule by the scientists has revealed that it absorbs ultraviolet light and then disperses it in a ‘flamenco-style’ dance, making it ideal for use as a UV filter in sunscreens.

The team of scientists report today, Friday 18th October 2019, in the journal Nature Communications that, as well as being plant-inspired, this molecule is also among a small number of suitable substances that are effective in absorbing light in the Ultraviolet A (UVA) region of wavelengths. It opens up the possibility of developing a naturally-derived and eco-friendly sunscreen that protects against the full range of harmful wavelengths of light from the sun.

The UV filters in a sunscreen are the ingredients that predominantly provide the protection from the sun’s rays. In addition to UV filters, sunscreens will typically also include:

Emollients, used for moisturising and lubricating the skin
Thickening agents
Emulsifiers to bind all the ingredients
Water
Other components that improve aesthetics, water resistance, etc.

The researchers tested a molecule called diethyl sinapate, a close mimic to a molecule that is commonly found in the leaves of plants, which is responsible for protecting them from overexposure to UV light while they absorb visible light for photosynthesis.

They first exposed the molecule to a number of different solvents to determine whether that had any impact on its (principally) light absorbing behaviour. They then deposited a sample of the molecule on an industry standard human skin mimic (VITRO-CORNEUM®) where it was irradiated with different wavelengths of UV light. They used the state-of-the-art laser facilities within the Warwick Centre for Ultrafast Spectroscopy to take images of the molecule at extremely high speeds, to observe what happens to the light’s energy when it’s absorbed in the molecule in the very early stages (millionths of millionths of a second). Other techniques were also used to establish longer term (many hours) properties of diethyl sinapate, such as endocrine disruption activity and antioxidant potential.

Professor Vasilios Stavros from the University of Warwick, Department of Chemistry, who was part of the research team, explains: “A really good sunscreen absorbs light and converts it to harmless heat. A bad sunscreen is one that absorbs light and then, for example, breaks down potentially inducing other chemistry that you don’t want. Diethyl sinapate generates lots of heat, and that’s really crucial.”

When irradiated the molecule absorbs light and goes into an excited state but that energy then has to be disposed of somehow. The team of researchers observed that it does a kind of molecular ‘dance’ a mere 10 picoseconds (ten millionths of a millionth of a second) long: a twist in a similar fashion to the filigranas and floreos hand movements of flamenco dancers. That causes it to come back to its original ground state and convert that energy into vibrational energy, or heat.

It is this ‘flamenco dance’ that gives the molecule its long-lasting qualities. When the scientists bombarded the molecule with UVA light they found that it degraded only 3% over two hours, compared to the industry requirement of 30%.

Dr Michael Horbury, who was a Postgraduate Research Fellow at The University Warwick when he undertook this research (and now at the University of Leeds) adds: “We have shown that by studying the molecular dance on such a short time-scale, the information that you gain can have tremendous repercussions on how you design future sunscreens.
Emily Holt, a PhD student in the Department of Chemistry at the University of Warwick who was part of the research team, said: “The next step would be to test it on human skin, then to mix it with other ingredients that you find in a sunscreen to see how those affect its characteristics.”

Professor Florent Allais and Dr Louis Mouterde, URD Agro-Biotechnologies Industrielles at AgroParisTech (Pomacle, France) commented: “What we have developed together is a molecule based upon a UV photoprotective molecule found in the surface of leaves on a plant and refunctionalised it using greener synthetic procedures. Indeed, this molecule has excellent long-term properties while exhibiting low endocrine disruption and valuable antioxidant properties.”

Professor Laurent Blasco, Global Technical Manager (Skin Essentials) at Lubrizol and Honorary Professor at the University of Warwick commented: “In sunscreen formulations at the moment there is a lack of broad-spectrum protection from a single UV filter. Our collaboration has gone some way towards developing a next generation broad-spectrum UV filter inspired by nature. Our collaboration has also highlighted the importance of academia and industry working together towards a common goal.”

Professor Vasilios Stavros added, “Amidst escalating concerns about their impact on human toxicity (e.g. endocrine disruption) and ecotoxicity (e.g. coral bleaching), developing new UV filters is essential. We have demonstrated that a highly attractive avenue is ‘nature-inspired’ UV filters, which provide a front-line defence against skin cancer and premature skin aging.”

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

Towards symmetry driven and nature inspired UV filter design by Michael D. Horbury, Emily L. Holt, Louis M. M. Mouterde, Patrick Balaguer, Juan Cebrián, Laurent Blasco, Florent Allais & Vasilios G. Stavros. Nature Communications volume 10, Article number: 4748 (2019) DOI: https://doi.org/10.1038/s41467-019-12719-z

This paper is open access.

Why the high hopes?

Briefly (the long story stretches over 10 years), the most recommended sunscreens today (2020) are ‘mineral-based’. This is painfully amusing because civil society groups (activists) such as Friends of the Earth (in particular the Australia chapter under Georgia Miller’s leadership) and Canada’s own ETC Group had campaigned against these same sunscreen when they were billed as being based on metal oxide nanoparticles such zinc oxide and/or titanium oxide. The ETC Group under Pat Roy Mooney’s leadership didn’t press the campaign after an initial push. As for Australia and Friend of the Earth, their anti-metallic oxide nanoparticle sunscreen campaign didn’t work out well as I noted in a February 9, 2012 posting and with a follow-up in an October 31, 2012 posting.

The only civil society group to give approval (very reluctantly) was the Environmental Working Group (EWG) as I noted in a July 9, 2009 posting. They had concerns about the fact that these ingredients are metallic but after a thorough of then available research, EWG gave the sunscreens a passing grade and noted, in their report, that they had more concerns about the use of oxybenzone in sunscreens. That latter concern has since been flagged by others (e.g., the state of Hawai’i) as noted in my July 6, 2018 posting.

So, rebranding metallic oxides as minerals has allowed the various civil society groups to support the very same sunscreens many of them were advocating against.

In the meantime, scientists continue work on developing plant-based sunscreens as an improvement to the ‘mineral-based’ sunscreens used now.

Safer sunblock and bioadhesive nanoparticles from Yale University

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The skin has a lot of protective barriers but it’s always possible to make something better so a sunblock that doesn’t penetrate the* skin at all seems like it might be a good thing. Interestingly, this new sunblock or sunscreen is enabled by nanoparticles but not the metallic nanoparticles found in what are sometimes called nanosunscreens. From a Sept. 29, 2015 news item on Nanowerk,

Researchers at Yale have developed a sunscreen that doesn’t penetrate the skin, eliminating serious health concerns associated with commercial sunscreens.

Most commercial sunblocks are good at preventing sunburn, but they can go below the skin’s surface and enter the bloodstream. As a result, they pose possible hormonal side effects and could even be promoting the kind of skin cancers they’re designed to prevent.

But researchers at Yale have developed a new sunblock, made with bioadhesive nanoparticles, that stays on the surface of the skin.

A Sept. 28, 2015 Yale University news release by William Weir, whch originated the news item, describes the research in more detail,

“We found that when we apply the sunblock to the skin, it doesn’t come off, and more importantly, it doesn’t penetrate any further into the skin,” said the paper’s senior author, Mark Saltzman, the Goizueta Foundation Professor of Biomedical Engineering. “Nanoparticles are large enough to keep from going through the skin’s surface, and our nanoparticles are so adhesive that they don’t even go into hair follicles, which are relatively open.”

Using mouse models, the researchers tested their sunblock against direct ultraviolet rays and their ability to cause sunburn. In this regard, even though it used a significantly smaller amount of the active ingredient than commercial sunscreens, the researchers’ formulation protected equally well against sunburn.

They also looked at an indirect — and much less studied — effect of UV light. When the active ingredients of sunscreen absorb UV light, a chemical change triggers the generation of oxygen-carrying molecules known as reactive oxygen species (ROS). If a sunscreen’s agents penetrate the skin, this chemical change could cause cellular damage, and potentially facilitate skin cancer.

“Commercial chemical sunblock is protective against the direct hazards of ultraviolet damage of DNA, but might not be against the indirect ones,” said co-author Michael Girardi, a professor of dermatology at Yale Medical School. “In fact, the indirect damage was worse when we used the commercial sunblock.”

Girardi, who specializes in skin cancer development and progression, said little research has been done on the ultimate effects of sunblock usage and the generation of ROS, “but obviously, there’s concern there.”

Previous studies have found traces of commercial sunscreen chemicals in users’ bloodstreams, urine, and breast milk. There is evidence that these chemicals cause disruptions with the endocrine system, such as blocking sex hormone receptors.

To test penetration levels, the researchers applied strips of adhesive tape to skin previously treated with sunscreen. The tape was then removed rapidly, along with a thin layer of skin. Repeating this procedure allowed the researchers to remove the majority of the outer skin layer, and measure how deep the chemicals had penetrated into the skin. Traces of the sunscreen chemical administered in a conventional way were found to have soaked deep within the skin. The Yale team’s sunblock came off entirely with the initial tape strips.

Tests also showed that a substantial amount of the Yale team’s sunscreen remained on the skin’s surface for days, even after exposure to water. When wiped repeatedly with a towel, the new sunblock was entirely removed. [emphasis mine]

To make the sunblock, the researchers developed a nanoparticle with a surface coating rich in aldehyde groups, which stick tenaciously to the outer skin layer. The nanoparticle’s hydrophilic layer essentially locks in the active ingredient, a hydrophobic chemical called padimate O.

Some sunscreen solutions that use larger particles of inorganic compounds, such as titanium dioxide or zinc oxide, also don’t penetrate the skin. For aesthetic reasons, though, these opaque sunscreen products aren’t very popular. By using a nanoparticle to encase padimate O, an organic chemical used in many commercial sunscreens, the Yale team’s sunblock is both transparent and stays out of the skin cells and bloodstream.

This seems a little confusing to me and I think clarification may be helpful. My understanding is that the metallic nanoparticles (nano titanium dioxide and nano zinc oxide) engineered for use in commercial sunscreens are also (in addition to the macroscale titanium dioxide and zinc oxide referred to in the Yale news release) too large to pass through the skin. At least that was the understanding in 2010 and I haven’t stumbled across any information that is contradictory. Here’s an excerpt from a July 20, 2010 posting where I featured portions of a debate between Georgia Miller (at that time representing Friends of the Earth) and Dr. Andrew Maynard (at that time director of the University of Michigan Risk Science Center and a longtime participant in the nanotechnology risk discussions),

Three of the scientists whose work was cited by FoE as proof that nanosunscreens are dangerous either posted directly or asked Andrew to post comments which clarified the situation with exquisite care,

Despite FoE’s implications that nanoparticles in sunscreens might cause cancer because they are photoactive, Peter Dobson points out that there are nanomaterials used in sunscreens that are designed not to be photoactive. Brian Gulson, who’s work on zinc skin penetration was cited by FoE, points out that his studies only show conclusively that zinc atoms or ions can pass through the skin, not that nanoparticles can pass through. He also notes that the amount of zinc penetration from zinc-based sunscreens is very much lower than the level of zinc people have in their body in the first place. Tilman Butz, who led one of the largest projects on nanoparticle penetration through skin to date, points out that – based on current understanding – the nanoparticles used in sunscreens are too large to penetrate through the skin.

However, there may be other ingredients which do pass through into the bloodstream and are concerning.

One other thing I’d like to note. Not being able to remove the sunscreen easily ( “When wiped repeatedly with a towel, the new sunblock was entirely removed.”) may prove to be a problem as we need Vitamin D, which is for the most part obtainable by sun exposure.

In any event, here’s a link to and a citation for the paper,

A sunblock based on bioadhesive nanoparticles by Yang Deng, Asiri Ediriwickrema, Fan Yang, Julia Lewis, Michael Girardi, & W. Mark Saltzman. Nature Materials (2015) doi:10.1038/nmat4422 Published online 28 September 2015

This paper is behind a paywall.

*’teh’ changed to ‘the’ on June 6, 2016.

Risk assessments not the only path to nanotechnology regulation

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Nanowerk has republished an essay about nanotechnology regulation from Australia’s The Conversation in an Aug. 25, 2015 news item (Note: A link has been removed),

When it comes to nanotechnology, Australians have shown strong support for regulation and safety testing.

One common way of deciding whether and how nanomaterials should be regulated is to conduct a risk assessment. This involves calculating the risk a substance or activity poses based on the associated hazards or dangers and the level of exposure to people or the environment.

However, our recent review (“Risk Analysis of Nanomaterials: Exposing Nanotechnology’s Naked Emperor”) found some serious shortcomings of the risk assessment process for determining the safety of nanomaterials.

We have argued that these shortcomings are so significant that risk assessment is effectively a naked emperor [reference to a children’s story “The Emperor’s New Clothes“].

The original Aug. 24, 2015 article written by Fern Wickson (Scientist/Program Coordinator at GenØk – Centre for Biosafety in Norway) and Georgia Miller (PhD candidate at UNSW [University of New South Wales], Australia) points out an oft ignored issue with regard to nanotechnology regulation,

Risk assessment has been the dominant decision-aiding tool used by regulators of new technologies for decades, despite it excluding key questions that the community cares about. [emphasis mine] For example: do we need this technology; what are the alternatives; how will it affect social relations, and; who should be involved in decision making?

Wickson and Miller also note more frequently discussed issues,

A fundamental problem is a lack of nano-specific regulation. Most sector-based regulation does not include a “trigger” for nanomaterials to face specific risk assessment. Where a substance has been approved for use in its macro form, it requires no new assessment.

Even if such a trigger were present, there is also currently no cross-sectoral or international agreement on the definition of what constitutes a nanomaterial.

Another barrier is the lack of measurement capability and validated methods for safety testing. We still do not have the means to conduct routine identification of nanomaterials in the complex “matrix” of finished products or the environment.

This makes supply chain tracking and safety testing under real-world conditions very difficult. Despite ongoing investment in safety research, the lack of validated test methods and different methods yielding diverse results allows scientific uncertainty to persist.

With regard to the first problem, the assumption that if a material at the macroscale is safe, then the same is true at the nanoscale informs regulation in Canada and, as far as I’m aware, every other constituency that has any type of nanomaterial regulation. I’ve had mixed feelings about this. On the one hand, we haven’t seen any serious problems associated with the use of nanomaterials but on the other hand, these problems can be slow to emerge.

The second issue mentioned, the lack of a consistent definition internationally, seems to be a relatively common problem in a lot of areas. As far as I’m aware, there aren’t that many international agreements for safety measures. Nuclear weapons and endangered animals and plants (CITES) being two of the few that come to mind.

The lack of protocols for safety testing of nanomaterials mentioned in the last paragraph of the excerpt is of rising concern. For example, there’s my July 7, 2015 posting featuring two efforts: Nanotechnology research protocols for Environment, Health and Safety Studies in US and a nanomedicine characterization laboratory in the European Union. Despite this and other efforts, I do think more can and should be done to standardize tests and protocols (without killing new types of research and results which don’t fit the models).

The authors do seem to be presenting a circular argument with this (from their Aug. 24, 2015 article; Note: A link has been removed),

Indeed, scientific uncertainty about nanomaterials’ risk profiles is a key barrier to their reliable assessment. A review funded by the European Commission concluded that:

[…] there is still insufficient data available to conduct the in depth risk assessments required to inform the regulatory decision making process on the safety of NMs [nanomaterials].

Reliable assessment of any chemical or drug is a major problem. We do have some good risk profiles but how many times have pharmaceutical companies developed a drug that passed successfully through human clinical trials only to present a serious risk when released to the general population? Assessing risk is a very complex problem. even with risk profiles and extensive testing.

Unmentioned throughout the article are naturally occurring nanoparticles (nanomaterials) and those created inadvertently through some manufacturing or other process. In fact, we have been ingesting nanomaterials throughout time. That said, I do agree we need to carefully consider the impact that engineered nanomaterials could have on us and the environment as ever more are being added.

To that end, the authors make some suggestions (Note: Links have been removed),

There are well-developed alternate decision-aiding tools available. One is multicriteria mapping, which seeks to evaluate various perspectives on an issue. Another is problem formulation and options assessment, which expands science-based risk assessment to engage a broader range of individuals and perspectives.

There is also pedigree assessment, which explores the framing and choices taking place at each step of an assessment process so as to better understand the ambiguity of scientific inputs into political processes.

Another, though less well developed, approach popular in Europe involves a shift from risk to innovation governance, with emphasis on developing “responsible research and innovation”.

I have some hesitation about recommending this read due to Georgia Miller’s involvement and the fact that I don’t have the time to check all the references. Miller was a spokesperson for Friends of the Earth (FoE) Australia, a group which led a substantive campaign against ‘nanosunscreens’. Here’s a July 20, 2010 posting where I featured some cherrypicking/misrepresentation of data by FoE in the persons of Georgia Miller and Ian Illuminato.

My Feb. 9, 2012 posting highlights the unintended consequences (avoidance of all sunscreens by some participants in a survey) of the FoE’s campaign in Australia (Note [1]: The percentage of people likely to avoid all sunscreens due to their concerns with nanoparticles in their sunscreens was originally reported to be 17%; Note [2]: Australia has the highest incidence of skin cancer in the world),

Feb.21.12 correction: According to the information in the Feb. 20, 2012 posting on 2020 Science, the percentage of Australians likely to avoid using sunscreens is 13%,

This has just landed in my email in box from Craig Cormick at the Department of Industry, Innovation, Science, Research and Tertiary Education in Australia, and I thought I would pass it on given the string of posts on nanoparticles in sunscreens on 2020 Science over the past few years:
…

“An online poll of 1,000 people, conducted in January this year, shows that one in three Australians had heard or read stories about the risks of using sunscreens with nanoparticles in them,” Dr Cormick said.

“Thirteen percent of this group were concerned or confused enough that they would be less likely to use any sunscreen, whether or not it contained nanoparticles, putting them selves at increased risk of developing potentially deadly skin cancers.

“The study also found that while one in five respondents stated they would go out of their way to avoid using sunscreens with nanoparticles in them, over three in five would need to know more information before deciding.”

This article with Fern Wickson (with whom I don’t always agree perfectly but hasn’t played any games with research that I’m know of) helps somewhat but it’s going to take more than this before I feel comfortable recommending Ms. Miller’s work for further reading.

Nanotechnology and sunscreens: recalibrating positions and the excruciating business of getting it as right as possible

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I’ve been waiting for Andrew Maynard’s comments (on his 2020 Science blog) about the Friends of the Earth (FoE) guest bloggers’ (Georgia Miller and Ian Illuminato) response (ETA June 6, 2016: Just how risky can nanoparticles in sunscreens be? Friends of the Earth respond; a 2020 Science blog June 15, 2010 posting) to his posting (Just how risky could nanoparticles in sunscreens be?) where he challenged them to quantify the nanosunscreen risk to consumers.  His reflections on the FoE response and the subsequent discussion are well worth reading. From Andrew’s posting, The safety of nanotechnology-based sunscreens – some reflections,

Getting nanomaterials’ use in context. First, Georgia and Ian, very appropriately in my opinion, brought up the societal context within which new technologies and products are developed and used:

“why not support a discussion about the role of the precautionary principle in the management of uncertain new risks associated with emerging technologies? Why not explore the importance of public choice in the exposure to these risks? Why not contribute to a critical discussion about whose interests are served by the premature commercialisation of products about whose safety we know so little, when there is preliminary evidence of risk and very limited public benefit.”

Andrew again,

… we need to think carefully about how we use scientific knowledge and data – “evidence” – in making decisions.

As he goes on to point out, cherrypicking data isn’t a substantive means of supporting your position over the long run.

Unfortunately it’s a common practice on all sides ranging from policymakers, politicians, civil society groups, consumers, medical institutions, etc. and these days we don’t have the luxury, ignorance about downsides such as pollution and chemical poisoning on a global scale for example, that previous generations enjoyed.

Three of the scientists whose work was cited by FoE as proof that nanosunscreens are dangerous either posted directly or asked Andrew to post comments which clarified the situation with exquisite care,

Despite FoE’s implications that nanoparticles in sunscreens might cause cancer because they are photoactive, Peter Dobson points out that there are nanomaterials used in sunscreens that are designed not to be photoactive. Brian Gulson, who’s work on zinc skin penetration was cited by FoE, points out that his studies only show conclusively that zinc atoms or ions can pass through the skin, not that nanoparticles can pass through. He also notes that the amount of zinc penetration from zinc-based sunscreens is very much lower than the level of zinc people have in their body in the first place. Tilman Butz, who led one of the largest projects on nanoparticle penetration through skin to date, points out that – based on current understanding – the nanoparticles used in sunscreens are too large to penetrate through the skin.

These three comments alone begin to cast the potential risks associated with nanomaterials in sunscreens in a very different light to that presented by FoE. Certainly there are still uncertainties about the possible consequences of using these materials – no-one is denying that. But the weight of evidence suggests that nanomaterials within sunscreens – if engineered and used appropriately – do not present a clear and present threat to human health.

Go to the comments section of the 2020 Science blog for the full text of Peter Dobson’s response, Brian Gulson’s response posted by Andrew on Gulson’s behalf, and Tilman Butz’s response posted by Andrew on Butz’s behalf. (I found these comments very helpful as I had made the mistake of assuming that there was proof that nanoparticles do penetrate the skin barrier [as per my posting of June 23, 2010].)

I want to point out that the stakes are quite high despite the fact that sunscreens are classified as a cosmetic. I’ve heard at least one commentator (Pat Roy Mooney of The ETC Group, Interview at 2009 Elevate Festival at 4:32) scoff because nanotechnology is being used in cosmetics as if it’s frivolous. Given the important role sunscreens play in our health these days, a safe sunscreen has to be high on the list of most people’s priorities but this leads to a question.

Should we stop developing more effective nanotechnology-enabled sunscreens (and by extension, other nanotechnology-enabled products) due to concern that we may cause more harm than good?

Andrew goes on to provide some interesting insight into the issue citing the Precautionary Principle and supplementing his comments with some of Richard Jones’ (author of Soft Machines book and blog and consultant to UK government on various nanotechnology topics) suggestions to refine the Precautionary Principle guidelines,

1. what are the benefits that the new technology provides – what are the risks and uncertainties associated with not realising these benefits?

2. what are the risks and uncertainties attached to any current ways we have of realising these benefits using existing technologies?

3. what are the risks and uncertainties of the new technology?

I strongly suggest that anyone interested in the issues around risk, the precautionary principle, emerging technologies, and the role of research read this posting (as well as its predecessors) and as much of the discussion as you can manage.

One additional thought which was posited in the comments section by Hilary Sutcliffe (you’ll need to scroll the comments as I haven’t figured out how to create a direct link to her comment) has to do with the role that companies have with regard to their research and making it available in the discussion about health, safety, and the environment (HSE),

… we need to be able to access ‘the best available information’ in order to make informed decisions in the face of uncertainty and enable the rounded assessment that Prof Richard Jones suggests. This is indeed essential, but ‘we’ are usually constrained by the lack of one very large chunk of ‘available information’ which is the HSE testing the companies themselves have done which leads them to judge the material or product they have developed is safe.

Further in the comment she goes on to discuss a project (What’s fair to share?) that her organization (MATTER) is planning where they want to discuss how companies can share their HSE data without giving away intellectual property and/or competitive advantages.

Finally, I want to paraphrase something I said elsewhere. While I am critical of the tactics used by the Friends of the Earth in this instance, there is no doubt in my mind that the organization and other civil society groups serve a very important role in raising much needed discussion about nanotechnology risks.