Acute Adverse Effects of Metallic Nanomaterials on Cardiac and Behavioral Changes in Daphnia magna
, Yongoh Lee 3, Changseon Ryu 2, Jayoung Park 2,* and Youngjun Kim 3,4
Round 1
Reviewer 1 Report
The research results presented in the author's article are an important step in improving the applied standards for determining toxicity. Since it is difficult to determine the real toxic effect on the human or fish organism for commonly used nanoparticles, which until now were considered non-toxic to human health, the authors took for the test organism a typical object of bioassay, a planktonic crustacean. Such a test organism, on the one hand, is an animal, that is, in terms of its physiology and nervous reactions, it is similar to a person, on the other hand, it turns out to be a non-target organism, on which more objective results can be obtained. Another advantage of the chosen organism for toxicity testing is its rapid response to exposure. The design of the experiments was correct, and the statistical significance was also assessed. The authors carried out a significant analysis of the available literature on this subject and provided the article with a sufficient bibliographic apparatus. The tasks set are consistent with the conclusion made by the authors. The work can be used to improve standard methods for assessing toxicity, for which the authors showed exactly how to apply the indices they developed. Of course, this is only a stage in the refinement of the standard, but an important stage that gives direction for its improvement, since in general daphnia, as a test organism, gives a very rough assessment of toxicity that requires further clarification and specialization. The article may be accepted for publication with minor corrections, which are noted in the attached comment file. The comments have a more technical aspect that requires accuracy in presentation; however, the authors should clarify the statement of the research problem to match their conclusions.
Comments for author File: 
Comments.pdf
Author Response
All authors are grateful for your comments and suggestions. We believe that you have contributed considerably to improving the quality of this manuscript. Both our answers and revisions to the text are presented in the following section. All revised contents have already been reflected in the main text (highlighted in yellow) in the clean copy of the main text. Please see the "Revised manuscript" file. Thank you.
Author Response File: Author Response.pdf
Reviewer 2 Report
Overall the manuscript is well written and contains publishable data.However, some comments need to be well described by the authors to
improve the quality of the manuscript:
- In the legend of figure 2, the authors indicate "Viability of D. magna
as a function of TiO2 and Ag nanoparticles (NPs) and Ag+. However, in this
figure there only two curves, one corresponding to Ti02 and the other
one to the silver ion (Ag+). This should be checked and revised?
- The ion (Ag+) indicated in the text and the legend of figures, corresponds
well to the effect of silver nitrate (AgNO3), this deserves to be
specified in the text and the legends of the figures.
- In the text, the authors specify that the effects of these nanoparticles
are sometimes significantly different compared to the controle (example in figs 3, 5 and 7).
However, in these figures no symbol (for example an asterisk) above the histograms
shows this significant difference compared to the controle. This needs
to be well reviewed.
- In addition, in the materials and methods section, the authors should
indicate that the results are expressed as a mean and standard deviation,
and clearly specify the statistical test used to compare between the treated
and the controle.
Author Response
All authors are grateful for your comments and suggestions. We believe that you have contributed considerably to improving the quality of this manuscript. Both our answers and revisions to the text are presented in the following section. All revised contents have already been reflected in the main text (highlighted in yellow) in the clean copy of the main text. Please refer to the page and line number shown at the bottom of each answer. Thank you.
Author Response File: Author Response.pdf
Reviewer 3 Report
environments-1567744, Acute adverse effects of metallic nanomaterials on cardiac and behavioral changes in Daphnia magna. The manuscript is well written. It presents a good research. The methods are correctly chosen and the results are presented in a coherent manner.
row 40, I advise the authors to present the information as “some nanomaterials”. The nanomaterials are so divers and there are a lot of factors to consider that any generalization could be dangerous.
Row 127, the concentration should be presented as powers of 10, like 10-4 for example
Row 137, present detail on Image J software (version)
Row 147, “immobilization of D. magna immobilization”
Row 161, detail please in the manuscript if it was only one observer or more and if the person(s) counting the heart rate were blind to the type of treatment.
Row 175, explain what ROS stands for
Row 184, the authors should test in the same conditions the solutions that were administered to D. magna. It is very possible (especially Ag ions) to have an impact on the DCFDA test.
Row 187, “The excitation state was maintained”. It sounds strange. Choose better the words.
Row 234, it should be 3-hours exposure
Figure 4, use the journal’s style with different panels (a, b,c…) and remove the grid. Enhance the images and improve their quality.
Row 248, the authors should make clear when the results refer to whole Daphnia and when to those homogenized.
Author Response
All authors are grateful for your comments and suggestions. We believe that you have contributed considerably to improving the quality of this manuscript. Both our answers and revisions to the text are presented in the following section. All revised contents have already been reflected in the main text (highlighted in yellow) in the clean copy of the main text. Please refer to the page and line number shown at the bottom of each answer. Thank you.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
I thank the authors for the answers given for all the reviewers' comments.
Author Response
All authors are grateful for your comments. We believe that you have contributed considerably to improving the quality of this manuscript. Thank you for your efforts.
