The biological effects of titanium dioxide nanoparticles depend on their crystalline forms

nanoparticles
TEM image of TiO2 NPs stock suspensions shape and size determination - JRC IHCP Nanobiosciences labs © EC - JRC, Nanobiosciences, 2016

Titanium dioxide powders have been manufactured and used on a large, industrial scale since the first half of the last century but only in recent years have concerns begun to be raised  about possible effects on human health though exposure to this material in nanoparticulate form.

Although some recent studies have reported that nanoparticulate titanium dioxide might be harmful to human health the situation still remains inconclusive due, in part, to the large number of different forms in which the material may be found. Not only is commercial titanium dioxide  produced with sizes ranging from a few nanometres to many microns but it can also be found different in crystal forms, such as  anatase, rutile and brookite, each of which may stimulate different responses in biological systems.

In this context, scientists from the JRC have investigated the biological effects of some specific crystalline forms of titanium dioxide within the frame of the EU-funded project NanoReTox. The studies were performed using in vitro mammalian cell cultures and supported the JRC activities related to optimisation of assays for nanomaterials safety testing.

In this study, the effects of nanosized and bulk titanium dioxide in two different crystalline forms (anatase and rutile) were investigated, using a set of in vitro assays optimised in the JRC laboratory for nanomaterials testing. Slight cytotoxic, genotoxic and neoplastic transformation effects were observed only in the presence of rutile, but not in the case of anatase nanoparticles.

 

Read more in the article Role of the crystalline form of titanium dioxide nanoparticles: Rutile, and not anatase, induces toxic effects in Balb/3T3 mouse fibroblasts. Toxicology In Vitro (2016) 31:137-45. doi: 10.1016/j.tiv.2015.11.005, Uboldi C, Urbán P, Gilliland D, Bajak E, Valsami-Jones E, Ponti J, Rossi F.