china tio2 products

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The production of ROS was studied on white blood cells as a model to screen the effect on eukaryotic cells after being exposed to samples and solar simulated irradiation (according to the level of penetration under the skin). For that purpose, the leukocytes were separated from anticoagulated fresh blood using the Ficoll-Hypaque reactive in a well-known technique [33]. Then, 50 μL of suspensions of P25TiO2NPs (0.2 mg/mL and 0.02 mg/mL), vitaminB2@P25TiO2NPs (0.2 mg/mL and 0.02 mg/mL) and vitamin B2 (0.2 mg/mL and 0.02 mg/mL) were prepared and mixed with 50 μL of white blood cells suspension. A solution of 3% H2O2 was used as positive control and PBS as negative control. Then, the samples were irradiated using the LED panel for 3 and 6 h to simulate the light penetration into the skin. Also, a set of samples was kept in the dark as control. Finally, the ROS were detected through the colorimetric assay employing the nitroblue tetrazolium salt (NBT salt) and the absorbance at 650 nm was measured. The experiment was reproduced twice; the standard deviation was calculated and p-value < 0.05 were considered significant.

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Freshwater algae show low-to-moderate susceptibility to TiO2 exposure, with more pronounced toxic effects in the presence of UV irradiation. It has also been shown that nano-sized TiO2 is significantly more toxic to algae Pseudokirchneriella sub-capitata than submicron-sized TiO2. Hund-Rinke and Simon  reported that UV irradiated 25 nm TiO2 NPs are more toxic to green freshwater algae Desmodesmus subspicatus than UV irradiated 50 nm particles, which is in agreement with Hartmann et al. UV irradiated TiO2 NPs also inactivated other algae species such as AnabaenaMicrocystisMelsoira and Chroococcus. It was demonstrated that smaller particles have a greater potential to penetrate the cell interior than submicron-sized particles and larger aggregates. Studies have shown that the amount of TiO2 adsorbed on algal cells can be up to 2.3 times their own weight.

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