Cytotoxicity: Small 18/2009

The frontispiece shows gold nanoparticles (AuNPs), the cytotoxicity of which critically depends on particle size, and 1.4-nm-diameter AuNPs capped with triphenylphosphine monosulfonate are much more cytotoxic than 15-nm nanoparticles. The effects of these 1.4-nm AuNPs are examined in detail on living cells. These toxic particles generate oxidative stress in cells, visible by leaky mitochondria (green monomeric JC-1 stain in the micrograph), and lead to necrosis. Furthermore, they up-regulate heat shock and stress-related genes, as can be seen in the hierarchical cluster analysis of a gene chip analysis (red bars in the heat-map representation). For more information, please read the Full Paper “Gold Nanoparticles of Diameter 1.4 nm Trigger Necrosis by Oxidative Stress and Mitochondrial Damage” by W. Jahnen-Dechent, U. Simon, et al., beginning on page 2067.