In vitro permeability of silver nanoparticles through porcine oromucosal membrane

Silver nanoparticles (AgNPs) can come in contact with human oral mucosa due to their wide use in food industry and hygiene devices. We evaluate transmucosal absorption of 19 nm AgNPs using excised porcine buccal mucosa applied on Franz diffusion cells. Two donor solutions were used: one containing AgNPs (0.5 g/L) and one derived from the ultrafiltration of the former and containing only Ag in its soluble form. Experiments were carried out separately for 4 h. Silver flux permeation was demonstrated through oral mucosa, showing similar values for AgNPs (6.8±4.5 ng cm(-2) h(-1)) and Ag ions (5.2±4.3 ng cm(-2) h(-1)). Our study demonstrates that silver can permeate the oromucosal barrier and that absorption is substantially due to Ag ions, since no permeation difference was found using the two solutions. Mucosal absorption has to be considered in further risk assessment studies.