Multigeneration impacts on Daphnia magna of carbon nanomaterials with differing core structures and functionalizations.
Bottom Line: Several classes of contaminants have been shown to have multigenerational impacts once a parental generation has been exposed.Certain nanomaterials, however, such as C60-malonate, SWCNTs, SWCNT-CONH2 , and MWCNTs, caused a significant decrease in either survival or reproduction in F1 daphnids; and SWCNT-CONH2 decreased reproduction out to the F2 generation.Impacts of nanomaterials on F1 and F2 size were small and lacked clear patterns, indicating that CNMs have minimal multigenerational impacts on size.
Affiliation: School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.Show MeSH
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Mentions: Six CNMs were synthesized by J. Chen at the University of Wisconsin-Milwaukee. These particles include C60-βCD (derivative 1), C60-amino (derivative 2), C60-amino-γCD (derivative 3), C60-malonic acid (derivative 4), C60-malonate (derivative 5), and C60-malonate-γCD (derivative 6) (Figure 1). Beta- and gamma-cyclodextrins (βCD and γCD, respectively) were ground with fullerenes in an agate mortar to yield derivatives 1, 3, and 6. Particles were suspended in deionized water by 1-h bath sonication in the absence of solvents and surfactants because this has been shown to change how the particles interact with organisms . The smallest average diameter was observed with C60-malonate-γCD particles (105 nm), followed by C60-βCD (107 nm), C60-amino (142 nm), C60-amino-γCD (152 nm), and C60-amino-γCD (175 nm). The most stable of these particle types were C60-malonate and C60-malonate-γCD, with more negative zeta (ζ) potential values (−63.8 mV and −47.7 mV), followed by C60-βCD (−42.2 mV), C60-amino (−17.07 mV), and C60-amino-γCD (−9.26 mV). Analysis by inductively coupled plasma mass spectroscopy indicated low levels of iron and copper in the suspensions (Supplemental Data, Table S1).
Affiliation: School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.