Interaction of sunscreen TiO2 nanoparticles with skin and UV light: Penetration, protection, phototoxicity

Alexey Popov, Jürgen Lademann, Alexander Priezzhev, Risto Myllylä

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific


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.

Original languageEnglish
Title of host publicationClinical and Biomedical Spectroscopy
EditorsIrene Georgakoudi, Jürgen Popp, Katarina Svanberg
PublisherOptical Society of America OSA
ISBN (Print)978-0-81947-644-9
Publication statusPublished - 1 Jan 2009
MoE publication typeNot Eligible
EventEuropean Conference on Biomedical Optics, ECBO 2009 - Munich, Germany
Duration: 14 Jun 200918 Jun 2009

Publication series

SeriesProgress in Biomedical Optics and Imaging
SeriesProceedings of SPIE


ConferenceEuropean Conference on Biomedical Optics, ECBO 2009


  • Nanoparticles
  • Phototoxicity
  • Skin
  • Sunscreen
  • UV light


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