Toxicology of nanosized titanium dioxide: an update

Nanosized titanium dioxide (nano-TiO2) has tremendous potential for a host of applications, and TiO2 nanoparticles (NP) possess different physicochemical properties compared to their fine particle analogs, which might alter their bioactivity. Their adverse effects on living cells have raised serious concerns recently for their use in health care and consumer sectors such as sunscreens, cosmetics, pharmaceutical additives and implanted biomaterials. Many researches have demonstrated that the physicochemical properties including shape, size, surface characteristics and inner structure of nano-TiO2 particles have different degrees of toxicity to different organism groups under different conditions. Some former reports have demonstrated that nano-TiO2 materials could enter into human body through different routes such as inhalation, dermal penetration and ingestion. After being taken by human body, NP might induce oxidative stress, cytotoxicity, genotoxicity, inflammation and cell apoptosis ultimately in mammal organs and systems. Here, we summarized the update about toxicity of nano-TiO2 and aimed to supply a safety usage guideline of this nanomaterial.