Effects of mechanical flexion on the penetration of fullerene amino acid-derivatized peptide nanoparticles through skin.

Dermatomed porcine skin was fixed to a flexing device and topically dosed with 33.5 mg.mL-1 of an aqueous solution of a fullerene-substituted phenylalanine (Baa) derivative of a nuclear localization peptide sequence (Baa-Lys(FITC)-NLS). Skin was flexed for 60 or 90 min or left unflexed (control). Confocal microscopy depicted dermal penetration of the nanoparticles at 8 h in skin flexed for 60 and 90 min, whereas Baa-Lys(FITC)-NLS did not penetrate into the dermis of unflexed skin until 24 h. TEM analysis revealed fullerene-peptide localization within the intercellular spaces of the stratum granulosum.