Silica nanoparticles (SiNPs) provide many possibilities in industrial, commercial, and biomedical fields. However little is known about the toxicological effects of SiNPs in the human. Caixia Guo and colleagues studied the impact of SiNP on the cardiovascular system. They sonicated stock suspensions of 58 nm SiNPs with the Bioruptor® in order to minimize their aggregation. The best dispersion obtained allows study of their interaction with human umbilical vein endothelial cells (HUVECs). Authors demonstrated that SiNPs could induce oxidative stress, inflammation, and NO/NOS system imbalance, and eventually lead to endothelial dysfunction via activation of the MAPK/Nrf2 pathway and nuclear factor-κB signaling. They underlined a potential deleterious effect of SiNPs on the vascular endothelium, which warrants more careful assessment of SiNPs before their application.