Behaviour of Titanium Dioxide Particles in Artificial Body Fluids and Human Blood Plasma.

The growing application of materials containing TiO particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO still exists. In this work, TiO particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO in these media were determined. The time dependent agglomeration of TiO related to the type of TiO, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO agglomeration. TiO was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO behavior in all the abovementioned environments is critical when TiO safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.