Silver nanoparticle-induced cytotoxicity in rat brain endothelial cell culture

► AgNPs impaired the uptake of Neutral Red (NR) dye in RBE4 cells. ► AgNPs above 1 μg/ml inhibited colony formation (i.e. proliferation potential) of RBE4 cells. ► A 0.054-3 μg/ml release of Ag+ ions was observed during a 24 h exposure period. ► The effects observed were dependent on particle size and surface area, dose and exposure time. ► Exposure to Ag+ ion-concentrations induced less damage to the cells than AgNPs.