Do quantum dots penetrate damaged skin?
The August issue of the journal Nano Letter (ASAP Article, 10.1021/nl801323y) features a paper entitled 'In Vivo Skin Penetration of Quantum Dot Nanoparticles in the Murine Model: The Effect of UVR', which the researchers present the results of a study that aimed to examine the impact of UV-radiation (UVR) on nanoparticle skin penetration by employing an in vivo semiconductor quantum dot nanoparticle (QD) model system (i.e. a system used to provides enhanced NP imaging capabilities). The researchers report that ‘low levels of penetration were seen in both the non-UVR exposed mice and the UVR exposed mice. Qualitatively higher levels of penetration were observable in the UVR exposed mice.’
In an article published by CosmeticsDesign.com, the authors of the paper warned that‘direct comparisons were impossible to make at this stage as a wide variety of surface coatings are used in commercial sunscreens that may alter skin penetration characteristics.’ They furthermore called for further research. “Future in-vivo studies using custom imaging modalities and commercial sunscreen formulations are planned to generate the necessary insight to assess human health risks from applying nanoparticle sunscreens to UV-damaged skin.’
The Nanotechnology Industries Association has prepared a full comment on this publication.
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The US Cancer Prevention Coalition criticised the lack of UVA protection in most sunscreens, and recommends the use of sun blocks with inorganic or mineral ingredients, such as TiO2 or ZnO, as adequate protection against UVA. (11th August 2008)
In its latest scientific assessment of nearly 1000 name-brand sunscreen, researchers Environmental Working Group (EWG), a US-based NGO, conclude ‘that zinc and titanium-based formulations are among the safest, most effective sunscreens on the market based on available evidence’. (1st July 2008)
The June issue of the journal Skin Pharmacology and Physiology features a paper that clarifies that ‘the current evidence suggests that nano-sized cosmetic or sunscreen ingredients pose no potential risk to human health, whereas their use in sunscreens has large benefits, such as the protection of human skin against skin cancer.’ (1st June 2008)
In response to the publication of the Friends of the Earth (FoE) report on Nanotechnology & Sunscreens, a paper entitled 'Rhetorical gamesmanship in the nano debates over sunscreens and nanoparticles' identifies that the FoE report uses a ‘risk profile shift’ from raw nanoparticles to sunscreen formulations to suggest environmental health and safety claims. (March 2008)
EU Project provides 1st evidence: ‘TiO2 nanoparticles do not penetrate through the intact skin’
This month's issue of Experimental Dermatology features a publication of the results of the NANODERM Project; the study reports the ‘first evidence that TiO2 nanoparticles in vivo do not penetrate through the intact epidermal barrier.’ (February 2008)
This month's issue of Experimental Dermatology features a publication of the results of the NANODERM Project; the study reports the ‘first evidence that TiO2 nanoparticles in vivo do not penetrate through the intact epidermal barrier.’ (February 2008)
Friends of the Earth published the result of an FoE survey of sunscreens, which concludes with a list of ‘non-chemical alternatives to staying safe in the sun, which include:
- staying in the shade, especially between the sun’s peak hours (10 a.m.- 4 p.m.),
- covering up with clothing, a brimmed hat and UV-blocking sunglasses,
- avoiding tanning and UV tanning booths,
- examining your skin head to toe every month, and
- seeing your physician every year for a professional skin exam.’
(14th August 2007)