Abstract
We report on a comparative study by Transmission Electron Microscopy (HRTEM) and Scanning Transmission Ion Microscopy (STIM) combined with Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-Ray Emission (PIXE) on ultra-thin and thin cross-sections, respectively, of various skin samples (porcine skin, healthy human skin, human skin grafted on a severe combined immuno-deficient mouse model) to which we applied topically various formulations containing titanium dioxide (TiO2) nanoparticles with primary particle sizes in the range from 20–100 nm. Whereas the HRTEM and STIM/PIXE images reveal clear differences – mainly related to the different thickness of the cross-sections – they unambiguously show that penetration of TiO2 nanoparticles is restricted to the topmost 3–5 corneocyte layers of the stratum corneum (SC).
Abbreviations | ||
PIXE | = | Particle Induced X-ray Emission |
STIM | = | Scanning Transmission Ion Microscopy |
HRTEM | = | High Resolution Transmission Electron Microscopy |
TiO2 | = | Titanium dioxide |
SC | = | Stratum corneum |
SG | = | Stratum granulosum |
SS | = | Stratum spinosum |
Abbreviations | ||
PIXE | = | Particle Induced X-ray Emission |
STIM | = | Scanning Transmission Ion Microscopy |
HRTEM | = | High Resolution Transmission Electron Microscopy |
TiO2 | = | Titanium dioxide |
SC | = | Stratum corneum |
SG | = | Stratum granulosum |
SS | = | Stratum spinosum |
Acknowledgements
The financial support by the European commission is gratefully acknowledged. RDT project is in the framework of the 5th PCRDT program “Quality of life” 2003–2005. KEY ACTION 4: environment and health. 4.1 Diseases and allergies related to or influenced by the environment and their prevention. NANODERM: percutaneous uptake of fine and ultrafine particles in bodycare and household products and its impact on human health. M. D. Ynsa was supported by the MEC (Ministerio de Educación y Cultura) through a post-doctoral grant. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.