Natural Transformation of Zinc Oxide Nanoparticles and Their Cytotoxicity and Mutagenicity

Figure 6

Morphology changes and variations in the survival fraction of cells treated with ZnO NPs with high/low-frequency exposure to air. Low resolution transmission electron microscopy (TEM) images of (a) pristine NPs, (b) NPs alkalized for 60 days with air exposure, and (c) NPs alkalized for 60 days without air exposure. Images of cells treated with (d) pristine, (e) NPs alkalized for 60 days with air exposure, and (f) NPs alkalized for 60 days without air exposure at 15 μg/mL for 72 h. Survival fractions of cells treated with (g) pristine, (h) NPs alkalized for 60 days with air exposure, and (i) NPs alkalized for 60 days without air exposure for 72 h. The data are presented as of at least three independent experiments. Significance is indicated by .

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