Jean Etienne Surlève-Bazeille

Is there penetration of titania nanoparticles in sunscreens through skin? A comparative electron and ion microscopy study

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).

Microanalysis of the human skin structure: preliminary results

Abstract In this paper, we report micro-PIXE analysis of normal human skin sections. The aim of this preliminary study was to investigate the tissue morphology using the distribution pattern of mineral ions. We found that these minerals were compartmentalized enough to constitute useful markers of the tissue ultrastructure. The epidermis and its different skin strata, corneum, granulosum and spinosum, were actually identified on elemental maps. The present work also provided additional useful information about minerals in the intradermal part of hair tracts. Methodological points will be evoked on the basis of this experience, more especially those concerning the sampling procedure.