Morphology of Colloid-Derived Nanostructures and Structure-Induced Cytotoxicity under Electric Potential Stress

In this study, the morphology of two sizes of nanoparticles under different preparation solvents is evaluated. The vendor marked 5 nm sphere-like nanomaterials are not dispersed in water and toluene solvents, while the vendor marked 1-2 mu m nanoparticles are well-dispersed in the water and environments. The behavior of solvent-induced dispersion or aggregation of TiO2 nanomaterials has less relationship with the solvent polarity, but the dimension of nanomaterials has significant effect on the aggregation or dispersion behaviors. The morphology of nanoparticles from these solvents is, therefore, used to explain the observed cytotoxicity. The cytotoxicity of TiO2 particles with different sizes and concentrations are evaluated by MTT assay using murine embryotic fibroblast (NIH/3T3 cells). Most of the TiO2 materials of interest are not cytotoxicity, except for the minor toxic effect to 5 nm spherical nanomaterials at the concentration ranging from 5x10(-6) to 5x10(-2) mu g/mL. These spherical nanoparticles with 1-2 mu m dimension demonstrate no cytotoxicity for dosages ranging from 5x10(-6) to 50 mu g/mL, irrespective of the dosing time and dispersion behavior. The cytotoxicity of applied electrical potential is strongly dependent on the initial size of nanoparticles. The smallest 5 nm nanomaterials seems more to toxicity with duration of electric potential from 10 V stress. On the contrary, the vendor marked 1-2 mu m nanoparticles owing to largest sizes demonstrates no significant cytotoxicity.