Toxicity assessment of six titanium dioxide nanoparticles in human epidermal keratinocytes

AbstractPurpose: The aim of this study was to evaluate and compare the toxicity of six different types of titanium dioxide (TiO2) nanoparticles (NP) on human epidermal keratinocytes (HEK).Materials and methods: Six TiO2 NP (A (10 nm), A*(32 nm), B (27.5 nm), C (200 nm), C*(30–40 nm), and D*(200–400 nm)) were suspended in water or culture medium and characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). In addition, these NP were assayed with cell viability, cytokine release and cellular uptake in HEK.Results: TiO2NP did not change in shape in the culture medium when visualized by TEM. There was an increase in agglomeration with all TiO2NP in the medium when measured by DLS. Since TiO2NP interfered with the CellTiter 96®AQueous One and MTT assays but had a minimal effect on alamar Blue (aB). The aB viability assay was selected to assess all six types of TiO2NP and sample B had a statistically significant decrease in viability at 0.4 mg/ml. A slight increase in TNF-α was...