Alteration of Haemoglobin States in Erythrocytes by TiO2 Quantum Dots

We have demonstrated that commercially available titanium dioxide (TiO2) powders contain TiO2 quantum dots with a diameter of approximately 1–2 nm, which readily penetrate cell membranes and enter cells, where they interact with proteins. The aim of our study was to assess the potential toxic effects of these quantum dots on red blood cells. Changes in the states of haemoglobin in red blood cells exposed to these quantum dots were demonstrated using Mössbauer spectroscopy. This article presents the results of in vitro studies carried out on isolated healthy erythrocytes exposed to TiO2 quantum dots at two concentrations, i.e., approximately 1.2 x 10-9 ng and 8.1x 10-9 ng of TiO2 quantum dots per cell. These are the concentrations one can expect, assuming that only 0.3% of these quantum dots accumulate in red blood cells after 7 and 45 days of exposure, respectively, in accordance with the guidance of the US National Institute for Occupational Safety and Health regarding the permissible exposure limit of 0.3 mg of very fine TiO2 nanoparticles per cubic metre over a 40-h working week.