@inbook{83b74278e9a140ea9550991581356cd2,
title = "Interaction of sunscreen TiO2 nanoparticles with skin and UV light: Penetration, protection, phototoxicity",
abstract = "Titanium dioxide (TiO2) nanoparticles are extensively used nowadays in sunscreens as protective compounds for human skin from UV radiation. In this paper, such particles are investigated from the viewpoint of penetration into living skin, UV protective properties (compared with silicon (Si) particles) and as sources of free radicals if UV-irradiated. We show that: a) even after multiple applications, the particles are located within the uppermost 3-??m-thick part of the skin; b) the optimal sizes are found to be 62 nm and 55 nm, respectively for TiO2 and Si particles for 310-nm light and, correspondingly, 122 and 70 nm - for 400-nm radiation; c) if applied onto glass, small particles of 25 nm in diameter produce an increased amount of free radicals compared to the larger ones of 400 nm in diameter and placebo itself; however, if applied onto porcine skin in vitro, there is no statistically distinct difference in the amount of radicals generated by the two kinds of particles on skin and by the skin itself. This proves that although particles as part of sunscreens produce free radicals, the effect is negligible in comparison to the production of radicals by skin in vitro.",
keywords = "Nanoparticles, Phototoxicity, Skin, Sunscreen, UV light",
author = "Alexey Popov and J{\"u}rgen Lademann and Alexander Priezzhev and Risto Myllyl{\"a}",
year = "2009",
month = jan,
day = "1",
doi = "10.1364/ECBO.2009.7368_22",
language = "English",
isbn = "978-0-81947-644-9",
series = "Progress in Biomedical Optics and Imaging",
publisher = "Optica Publishing Group",
number = "44",
editor = "Irene Georgakoudi and J{\"u}rgen Popp and Katarina Svanberg",
booktitle = "Clinical and Biomedical Spectroscopy",
address = "United States",
note = "European Conference on Biomedical Optics, ECBO 2009 ; Conference date: 14-06-2009 Through 18-06-2009",
}