On July 29, 2009, Particle and Fibre Toxicology posted an article entitled “Maternal Exposure to Nanoparticulate Titanium Dioxide During the Prenatal Period Alters Gene Expression Related to Brain Development in the Mouse.” The purpose of the study was to investigate the effects of maternal exposure to nano-sized anatase titanium dioxide on gene expression in the brain during the developmental period. According to the authors, analysis of gene expression indicated that expression levels of genes associated with apoptosis were altered in the brain of newborn pups, and those associated with brain development were altered in early age. Genes associated with response to oxidative stress were changed in the brains of two- and three-week old mice. The authors concluded that maternal exposure of mice to titanium dioxide nanoparticles “may affect the expression of genes related to the development and function of the central nervous system.” A July 17, 2009, ACS Nano article entitled “Cellular Toxicity of TiO2-Based Nanofilaments” concludes that titanium dioxide-based nanofilaments “are cytotoxic and thus precautions should be taken during their manipulation.” The authors studied the cellular toxicity of titanium dioxide-based nanofilaments in relation to their morphology and surface chemistry.