North Carolina State and Rice University researchers recently published the results of their in vivo skin penetration experiments using fullerenes on pig skin. The researchers tested fullerene penetration on stationary skin and skin that was flexed for an hour or an hour and a half. They found the longer the skin was flexed, the greater and deeper the particle uptake. Additionally, they found greater uptake 24 hours after flexion than that measured eight hours after flexion. N Monteiro-Riviere, et al., Nano Letters, American Chemical Society, January 10, 2007.
It is interesting to compare the Cosmetic, Toiletry and Fragrance Association’s October 10, 2006 "Nanotechnology White Paper: The Use of Nanotechnology in Personal Care Products," (maintaining scientific evidence confirms a lack of dermal absorption of nanoparticles), as well as recent efforts by the Pharmos Corporation to develop a dermal drug delivery nano-emulsion.
