title: Titanium dioxide nanoparticles: a review of current toxicological data.
abstract: Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide in large quantities for use in a wide range of applications. TiO2 NPs possess different physicochemical properties compared to their fine particle (FP) analogs, which might alter their bioactivity. Most of the literature cited here has focused on the respiratory system, showing the importance of inhalation as the primary route for TiO2 NP exposure in the workplace. TiO2 NPs may translocate to systemic organs from the lung and gastrointestinal tract (GIT) although the rate of translocation appears low. There have also been studies focusing on other potential routes of human exposure. Oral exposure mainly occurs through food products containing TiO2 NP-additives. Most dermal exposure studies, whether in vivo or in vitro, report that TiO2 NPs do not penetrate the stratum corneum (SC). In the field of nanomedicine, intravenous injection can deliver TiO2 nanoparticulate carriers directly into the human body. Upon intravenous exposure, TiO2 NPs can induce pathological lesions of the liver, spleen, kidneys, and brain. We have also shown here that most of these effects may be due to the use of very high doses of TiO2 NPs. There is also an enormous lack of epidemiological data regarding TiO2 NPs in spite of its increased production and use. However, long-term inhalation studies in rats have reported lung tumors. This review summarizes the current knowledge on the toxicology of TiO2 NPs and points out areas where further information is needed.
authors.affiliation: Public Health Department of Medical School, Zhejiang Provincial Key Laboratory of Pathological and Physiological Technology, Ningbo University, Ningbo, Zhejiang Province, 315211, PR China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Shi
authors.forename: Ruth
authors.initials: R
authors.lastname: Magaye
authors.forename: Vincent
authors.initials: V
authors.lastname: Castranova
authors.forename: Jinshun
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D007408:Intestinal Absorption; D053768:Metal Nanoparticles; D016273:Occupational Exposure / Q000009:adverse effects; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism; D018570:Risk Assessment; D012869:Skin Absorption; D013997:Time Factors; D014025:Titanium / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000633:toxicity; D018675:Toxicity Tests
chemical_list: C009495:titanium dioxide; D014025:Titanium