In vitro evaluation of the cytotoxicity of iron oxide nanoparticles with different coatings and different sizes in A3 human T lymphocytes.

The ever expanding use of engineered nanoscaled materials has brought about a commensurate growth in concern about their potential risks to human and environmental health. Toxicity of nanoparticles could vary with their physicochemical parameters. The dependence of cytotoxicity on particle size and surface coating of iron oxide nanoparticles was investigated in this in vitro study using the A3 human T lymphocyte as a model. Two different sizes (10 nm and 50 nm) and two different surface coatings (amine and carboxyl groups) of iron oxide (IO) nanoparticles were tested with fluorescein diacetate (FDA) assay and WST-1 assay. In the 1-h FDA assay with PBS, IO nanoparticles did not show size-dependent toxicity to A3 cells in terms of mass concentration; however, in terms of the number of particles per well and the total surface area, they did exhibit size-dependent toxicity. Fifty nanometer IO nanoparticles are more toxic than the 10 nm counterparts. The results of both the 24-h FDA and WST-1 assays in a complete growth medium indicate size- and surface coating-dependent toxicity to A3 cells in terms of mass concentration. IO nanoparticles of the smaller size are more toxic than those of the larger size. IO nanoparticles with the carboxyl group have a higher toxicity than those with the amine group. However, in the 24-h FDA assay, in terms of the number of particles per well and the resultant total surface area per well, the 50 nm IO nanoparticles are more toxic than those of size 10 nm. In terms of mass concentration, the number of particles per well and the total surface area, both of the 24-h assays showed the consistent results that IO nanoparticles with the carboxyl group have a higher toxicity than those with the amine group. Copyright 2010 Elsevier B.V. All rights reserved.