In recent decades, the development of nanomaterials based on titanium oxide and their use in the household and medical fields has been carried out on an industrial scale. As a result, for now, there are problems in studying the bioavailability of titanium dioxide, as well as assessing their effects on cells and tissues of the human body.
The aim of this study is to evaluate the ability of human erythrocytes to accumulate titanium after exposure to titanium dioxide particles of different sizes (nano-, micro-and dietary particles), as well as to investigate the activity of antioxidant protection enzymes in erythrocytes after exposure to titanium dioxide.
Erythrocytes were separated from plasma by blood centrifugation at 2000 g, 5 minutes in PBS buffer pH 7,4. After reparation erythrocytes were diluted to 2% hematocrit in the same buffer and loaded with titanium dioxide particles at the final concentration of 0,01 mg/ml and incubated for 3 hours at 37°C and permanent mixing. Analysis of the elemental composition of erythrocytes was realized by inductively coupled plasma atomic emission spectroscopy. Catalase and glutathione peroxidase activity were assessed by the standard methods [1, 2]. Statistical analysis was carried out using Wilcoxon test (n=7).
It was shown that after 3-h of incubation with the analyzed particles there was no reliable change of titanium content in the cells. The maximum values of titanium in erythrocytes were 1,57; 2,36 and 0,49 μg/L in treatment groups with nanoparticles, microparticles and dietary TiO2 respectively, while in the control sample the average titanium content was 1,01 μg/L.
Analysis of the activity of antioxidant protection enzymes (glutathione peroxidase and catalase) revealed that after a 3-h load of TiO2 cells, there was a decrease in the activity of the studied enzymes on average by 20% (p<0.05). However, the difference between the effects of different types of particles could not be identified.
Thus, we have found that the 3-h load of human erythrocytes by various types of titanium dioxide particles (nano-, microparticles and dietary titanium) does not lead to its accumulation in cells, nevertheless, it causes a decrease in the activity of enzymes of antioxidant protection.