One-to-one comparison of sunscreen efficacy, aesthetics and potential nanotoxicity


Numerous reports have described the superior properties of nanoparticles and their diverse range of applications. Issues of toxicity1,2, workplace safety3,4 and environmental impact5,6,7,8,9 have also been a concern. Here we show a theoretical comparison of how the size of titanium dioxide nanoparticles and their concentration in sunscreens can affect efficacy, aesthetics and potential toxicity from free radical production. The simulation results reveal that, unless very small nanoparticles can be shown to be safe, there is no combination of particle size and concentration that will deliver optimal performance in terms of sun protection and aesthetics. Such a theoretical method complements well the experimental approach for identifying these characteristics.

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Figure 1: Prediction of size-dependent SPF.
Figure 2: Prediction of the size-dependent transparency, which governs aesthetic appeal.
Figure 3: Prediction of the potential for generation of ROS as a function of nanoparticle size.
Figure 4: Prediction of the efficacy, transparency and potential for nanotoxicity of titania nanoparticles in sunscreens.
Figure 5: Numerical simulation of optimal product attributes.


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A.S.B. acknowledges the support of the Australian Research Council (ARC) (DP0986752), L'Oréal Australia, and the Australian Academy of Sciences, and G. Smith and H. Xu for useful discussions.

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Correspondence to Amanda S. Barnard.

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Barnard, A. One-to-one comparison of sunscreen efficacy, aesthetics and potential nanotoxicity. Nature Nanotech 5, 271–274 (2010).

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