Objectives

New methodologies (high-resolution ion microscopy, radiotracer)  on skin cross sections will be established to study the quality of skin as a barrier against formulations containing nanoparticles. Whereas the cellular response to such particles is well documented, it is not yet clear whether such particles effect the horny layer only or indeed penetrate into vital tissue. Tape stripping experiments are not conclusive because they have no lateral and limited depth resolution and stop at the dermis. Electron microscopy identifies individual particles but is less suited for large scan elemental maps. However, ion microscopy yields elemental maps with µg/g detection limits. If such particles penetrate into vital tissue, in-situ and in-vitro studies of tissue and cells will follow.