Silica nanoparticles suppress fibronectin-mediated adhesion and migration in normal human keratinocytes.

Nanotechnology has been increasingly applied to various fields, such as biology, chemistry, physics, medicine and engineering. However, a major concern that has been the topic in nanoscience is whether exposure of humans to engineered nanoparticles might cause toxic effects. In the present in vitro study, the influence of silica nanoparticles on fibronectin-mediated cellular response was assessed in normal human keratinocytes. Our results demonstrated that silica nanoparticles but not silica microparticles significantly suppressed cell adhesion and migration to fibronectin. This phenomenon was not observed in cell response to Poly-L-Lysine, which mediates cell adhesion and migration in a way different from that of fibronectin. Moreover, it seemed that this suppression was not due to cytotoxic effects induced by silica nanoparticles. Subsequently, we also showed that silica nanoparticles impaired the fibronectin-induced activation of FAK and its downstream PI3K, AKT and Src. Taken together, our data suggests that silica nanoparticles may negatively modulate cell response to fibronectin.