ZnO and TiO2 particles: a study on nanosafety and photoprotection

Alexey Popov*, Xin Zhao, Andrei Zvyagin, Jürgen Lademann, Michael Roberts, Washington Sanchez, Alexander Priezzhev, Risto Myllylä

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

9 Citations (Scopus)


Nanoparticles of titanium dioxide (TiO2) and zinc oxide (ZnO) are used in sunscreens as protective compounds against UV radiation. We investigate these particles from the viewpoint of nanosafety (penetration into skin in vivo, production of free radicals when UV-irradiated) as well as UV protection. We show that: a) even after multiple applications, the particles remain within stratum corneum (uppermost skin layer); b) the optimal sizes are 62 nm and 45 nm, respectively for TiO2 and ZnO particles for 310-nm light and, correspondingly, 122 and 140 nm - for 400-nm radiation; c) in general, small particles (25 nm in diameter) are more photoactive than the larger ones (400 nm in diameter); however, on the background if porcine skin in vitro this difference is not seen and is substantially surpassed by skin contribution into production of free radicals.

Original languageEnglish
Title of host publicationBiophotonics
Subtitle of host publicationPhotonic Solutions for Better Health Care II
Place of PublicationWashington, DC
Number of pages7
ISBN (Print)9780819481887
Publication statusPublished - 2010
EventBiophotonics: Photonic Solutions for Better Health Care II - Brussels, Belgium
Duration: 12 Apr 201016 Apr 2010

Publication series

NameProceedings of SPIE
ISSN (Electronic)1605-7422
NameProgess in Biomedical Optics and Imaging


ConferenceBiophotonics: Photonic Solutions for Better Health Care II
CityBrussels, Belgium


  • Nanoparticles
  • Nanosafety
  • Phototoxicity
  • Skin
  • Sunscreen
  • TiO
  • UV light
  • ZnO


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