Using thermal diffusivity as a cytotoxic evaluation tool for silica nanoparticles

Silicon dioxide nanoparticles are receiving increasing attention due to their new properties and wide applications. The aim of this study was to investigate the cytotoxic potential of 300 nm SiO₂ nanospheres on erythrocytes using thermal diffusivity values. Cytotoxicity was correlated with thermal diffusivity of the hemolysates; thermal values ​​were from 10.00 ± 0.40 × 10^− 4 cm²/s to 12.20 ± 0.07 × 10^− 4 cm²/s. The concentrations tested were 50, 100, 200, 400 and 800 µg/ml of silica nanoparticles. To evaluate cytotoxicity, human erythrocytes were obtained. Hemolytic damage in red blood cells had an exponential behavior dependent on the concentration of SiO₂ nanostructures. The use of concentrations of 800 µg/ml exceeds the limit of compatibility for human red blood cells. Antioxidant enzyme quantification assays were also performed in which a dose-dependent depletion of catalase activity levels and an increase in glutathione S-transferase was observed. Therefore, oxidative stress was suggested as a mechanism of toxicity in erythrocytes.