No abstract

This investigation was designed to determine whether silver nanoparticles (Ag‐45 nm) induce any selective and specific biological effects upon coronary endothelial cells (CEC), such as proliferation, cytotoxicity, and nitric oxide production (NO). CEC were cultured and exposed to increasing concentrations (0.1‐100μg/ml) of Ag‐45 nm for 24 hrs. Ag‐45 induced dual effect upon cellular proliferation, an inhibition at low concentrations and stimulation at high concentrations, and these actions were directly associated with NO production and inversely related with cytotoxicity. Confocal microscopy studies showed that Ag‐45 nm exposure, did not change CEC morphology, and were distributed widely in cellular surface, even with high concentrations of this agglomerate nanomaterial (NM). In addition, physical characterization of these Ag‐45 nm, using transmission electron microscopy, demonstrated that the real range of this NM, compromise a heterogeneous group of silver sizes, from 10‐90 nm. These results clearly demonstrate that Ag‐45 nm show selective and specific effects on this vascular bed, depending on the concentration, and that opposite effect could be result of the heterogeneity of sizes. However, the protective effects we found could be mediated by the production of NO, a free radical produced mostly by endothelium from blood vessels and, mediated angiogenesis and vascular tone.