I visited the National Institute for Environmental Studies in Tsukuba, Japan from 3.05.2013 till 30.07.2013 as a part of Work Package 2 “Carrying out experiments to produce necessary (missing) data for NPs”.
During this time I worked on selection and optimisation of reliable in vitro method employing mammalian cell line as a model system to assess toxicity of engineered nanomaterials especially titanium dioxide modified with noble metals (Au, Pd. Ag, Pt). Different mammalian cell lines (A549, BEAS-2B, J774.1 and CHO-ARE)were tested for their sensitivity to the selected NPs. Since the primary and secondary sizes of NPs are regarded as important parameters for in vitro cytotoxicity therefore the behavior of the NPs in cell culture medium was evaluated through dynamic light scattering (DLS) to optimise the suspension preparation procedure in order to reduce the aggregation and secondary size of NPs before exposure experiments.
As the result of secondment the experimental data applicable for computational modelling of toxic potential (determined with CHO-ARE cell line using WST-8 assay) of titanium dioxide NPs modified with noble metals (Au, Pd, Ag, Pt) synthesized using microemulsion and sol-gel methods were obtained.
I was visiting National Institute for Environmental Studies in Tsukuba (Japan) between 02.05.2013 and 29.07.2013 within Work Package 2: Carrying out experiments to produce necessary (missing) data for nanoparticles. During this time thirty photocatalysts TiO2 modified with noble metal nanoparticles prepared by two different method (microemulsion and sol-gel) were characterized. Samples were obtained in different conditions (various: method, amount of metal and calcination temperature). This photocatalysts can be use for photodegradation of pollutants in the gas phase (eg, removal of VOCs from the air), water (for example, removal of phenols from water and wastewater) removing the odor of the enclosed space, the inactivation of bacteria, and in self-cleaning surfaces, to generate hydrogen and CO2 photoconversion for light hydrocarbons. The photocatalysts were systematically characterized using different analytical methods like X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), BET and Atomic Force Miscroscope (AFM). I also acquainted with procedure of toxicity measurements for TiO2-based nanocomposites. Based on obtained experimental data (BET surface area, crystal structure, morphology and toxicity) computational model will be developed to evaluate environmental risk of TiO2-based nanoparticles.
I have visited the University of Gdańsk (UG) between 22.10.2012 and 17.11.2012 within Work Package 3: Development of novel structural descriptors for nanoparticles.
We have discussed applicability of “liquid drop” model for nanoparticles’ description. It was developed some promising for toxicity of nano-sized metal oxides models with me and my PhD student Nataloia Novoselska.
Best models we included in paper, as a result of successful collaboration with our Polish colleagues.
I have worked at National Institute for Environmental Studies (NIES) in Tsukuba for 3 months. During my stay I have characterized cytotoxicity of the nanoparticles to collect data necessary for evaluation of the nano-QSAR model.
In order to deliver data for Work Package 2 „Carrying out experiments to produce necessary (missing) data for NPs” I have worked with two cell line: Chinese Hamster Ovary Cells and mouse macrophages J774.1. I have studied the effect of nanoparticles on cell metabolic activity and proliferation and tried to correlate it with nanoparticles uptake by the cells. Additionally, I took part in characterization of the nanoparticles by means of X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Selected Area Diffraction (SAD). read more >>
Between 15 and 29 of June I was visiting National Institute for Environmental Studies in Tsukuba (Japan) within Work Package 2: Carrying out experiments to produce necessary (missing) data for nanoparticles. Four series of TiO2 based nanoparticles was prepared by members of my research group and they will be systematically characterized to collect data regarding surface properties (including crystal structure, BET surface area, morphology and surface content) and toxicity. Based on obtained experimental data, computational model will be developed to evaluate environmental risk of TiO2-based nanoparticles.
TiO2 nanoparticles are the most researched photocatalytic material, because it provides the most efficient photocatalytic activity, the highest stability and the lowest cost. Pure and modified TiO2 is used both for degradation of organic and inorganic compounds in aqueous solutions and to remove microorganisms, e.g. in water and wastewater treatment and disinfection processes (Advanced Oxidation Technologies). Thus, TiO2 nanoparticles could be released to aqueous environment and affect organisms due to three potential mechanisms: (a) transport of nanoparticles via cell membrane; (b) release of metal ions from doped of modified TiO2 (noble and transient metals); or (c) formation of active oxygen species at irradiated TiO2 surface.
During my visit, procedure of toxicity measurements for TiO2-based nanocomposites was discussed and developed.
