Barrier impairment and time are among the top two factors affecting the penetration of ZnO nanoparticles into skin, a new study suggests. Notably, however, they do not penetrate in their nano form as they exist in sunscreens.
The report, pending publication in Applied Biomaterials, describes the use of healthy and impaired ex vivo skin plus artificial sweat and caprylic/capric triglyceride to assess potential ZnO nanoparticle penetration. Only in cases of compromised skin over time, or where nanoparticles were dissolved and non-representative of their form in sunscreens did they penetrate.
See related: Small, Smaller and Nano Materials, An Invisible Benefit
This work follows a recent study commissioned by the European Union's Observatory for Nanomaterials (EUON), whose review of the literature also found nanomaterials rarely absorb through intact skin.
