Adverse Effects of Titanium Dioxide Nanoparticles on Human Dermal Fibroblasts and How to Protect Cells

The effects of exposure of human dermal fibroblasts of rutile and anatase TiO2 nanoparticles are reported. These particles can impair cell function, with the latter being more potent at producing damage. The exposure to nanoparticles decreases cell area, cell proliferation, mobility, and ability to contract collagen. Individual particles are shown to penetrate easily through the cell membrane in the absence of endocytosis, while some endocytosis is observed for larger particles clusters. Once inside, the particles are sequestered in vesicles, which continue to fill up with increasing incubation time till they rupture. Particles coated with a dense grafted polymer brush are also tested, and using flow cytometry, are shown to prevent adherence to the cell membrane and hence penetration of the cell, which effectively decreasexs reactive oxygen species (ROS) formation and protects cells, even in the absence of light exposure. Considering the broad applications of these nonoparticles in personal health care products, the functionalized polymer coating can potentially play an important role in protecting cells and tissue from damage.