Novel Hydroxyapatite Whiskers Modified by Silver Ion and Nano Zinc Oxide Used for Bone Defect Repairment

Round 1

Reviewer 1 Report

Please, correct all spelling mistakes. Also, there are many sentences that are hard to understand. I recomend re-write  the article in order to make it clearer.

Comments for author File: Comments.pdf

Author Response

1. There are many grammatical mistakes. I found many sentences that there is not space between two words. For example, line 18 in the abstract section “copy(FESEM)” or in line 46 “Ce 2+ ” instead “Ce 2+ ”. Then, please correct all mistakes present in the article.

We are deeply sorry for our negligence. Regarding the phenomenon that there is no space between the two words in the article, we carefully checked the article and revised it.

2. Related to the abstract section, in my opinion, there are some sentences in the wrong place. Authors describe at the beginning of the abstract the HA and HAw and surface modification with Ag ion and ZnO particles. After that, describe the antibacterial activities against E. coli and S. aureus. Moreover, after that back to the microstructural description of the Haw and finally again about biological activity. In my opinion, the structure is not clear. It is better, for example, describe first the material and after that the biological behavior.

We have re-written this part according to the Reviewer’s suggestion. Describe the material

first, and then describe the biological behavior.

3. Line 14, abstract, authors indicated “The improvement of the antibacterial performance is a hot spot” I think that “hot spot” is not a scientific word. Please, find other expression

We have made correction according to the Reviewer’s comments. “Hot spot” has been changed to “aroused general interest”.

4. Line 18, abstract section, diffractometer is an equipment but if you are investigating the sample, maybe the correct word would be “analysis”

We have made correction according to the Reviewer’s comments. We have corrected it to

“analysis”.

5. Line 25, abstract section, authors wrote “The XRD analysis showed that the phase of nano

zinc oxide appeared in the diffraction pattern of ZnO/3Ag-Haw after the sol-gel and

calcination process”. I cannot understand such phrase. Even the next phrase “The TEM

micrographs analysis showed that the value of 5Ag-HAw increases slightly”. Does the

ZnO nanoparticles increase?

We have made correction according to the Reviewer’s comments. “The XRD analysis

showed that the phase of nano zinc oxide appeared in the diffraction pattern of ZnO/3Ag-Haw

after the sol-gel and calcination process” has been changed to “XRD analysis showed that

after sol-gel and calcination treatment, nano-zinc oxide phase appeared in the diffraction

pattern of ZnO/Ag-Haw”; “The TEM micrographs analysis showed that the value of 5Ag

HAw increases slightly” has been changed to “TEM analysis showed that the interplanar

spacing of 5Ag-HAw increased slightly”.

6. Page 2, line 49, “virusesand”, line 71 “atemplated-“, line 74 “nitratewere”, page 3 line 100, “phasecomposition”…… Please, correct al wrong words.

We are deeply sorry for our negligence. We have corrected the wrong word.

7. Page 3, line 101, “chemical contents” is wrong. Maybe is better “chemical composition” “chemical concentration”, etc.

We have made correction according to the Reviewer’s comments. “Chemical contents” has been changed to “Chemical composition”.

8. Page 3, line 109, what is “energy-dispersive X-ray spectrum-copy”?

We are deeply sorry for our negligence. “Energy-dispersive X-ray spectrum-copy” has been changed to “Energy Dispersive X-Ray Spectroscopy (EDX)”.

9. Page 3, line 115, “method, 5Ag-HAw、ZnO/5Ag-HAw”. Which is the symbol between Haw and ZnO”?

The symbol between ZnO and HAw is “/”.

10. Page 4, line 134, “mins” is wrong.

We are deeply sorry for our negligence. "Mins" has been modified.

11. Page 6, line 173, “Haw” instead “HAw”

We are deeply sorry for our negligence. “Haw” has been modified to “HAw”.

12. Page 6, line 176, “Pure HAwand”

We are deeply sorry for our negligence. “Pure HAwand” has been modified to “Pure HAw and”.

13. Page 6, line 183, what is “OCP”? “OCP” is not defined previously.

We are deeply sorry for our negligence. OCP is the abbreviation of octa-calcium phosphate, which has been annotated in the text.

14. Page 6, line 187 “both a-axes and c-axes” maybe is better “both a- and c-axis” ….

We have made correction according to the Reviewer’s comments. “both a-axes and c-axes”

has been modified to “both a- and c-axis”.

15. Page 10, line 259 “S. aureuswas shown”…there are many mistakes like that.

We are deeply sorry for our negligence. “S. aureuswas shown” has been modified to “S. aureus was shown”.

16. Page 6, line 167, authors said “The nano zinc oxide particles have a particle size distribution of 20-30 nm, and these nanoparticles.”. How did authors measure the particle size? It is not clear how they obtain such value.

We are deeply sorry for our negligence. We have modified Figure 1 and in Figure 1(e) we can clearly see the size of the nano-zinc oxide particles.

17. After that, authors indicated, “As it demonstrated by mapping (Fig.1f), Ag and Zn could be detected in the ZnO/3Ag-HAw samples.” Does it mean that Ag and Zn are not detected in other samples?

No, Figure 1(f) only shows that Zn and Ag are present in the ZO and Ag modified whiskers. This is a comparison with Pure whiskers, which shows that Ag and Zn are doped in HAw.

18. Page 9, line 218, “Table 3 shows the results of ICP-OES that the Ag+ concentration of the sample after 7d of immersion in PBS solution (pH=7.4).” What is the meaning of this phrase?

We are deeply sorry for our negligence. We have replaced it with “Table 4 shows the Ag+ concentration measured after the sample is immersed in a PBS solution of pH=7.4 for 7 days”.

Reviewer 2 Report

I went through the manuscript entitled “A novel hydroxyapatite whiskers modified by silver ion and nano zinc ox-2 ide used for bone defect repairment” written by Yan and co-workers and I found the subject of their study quite interesting and appealing. However, there is a number of concerns that must be all completely fulfilled before recommending the manuscript for publication in Coatings.

1) There are mistakes/misleading sentences throughout the manuscript, for example:

Lines (some) 27, 41-42, 71, 146-147, 180, 189,…..the authors must carefully check for others and edit all the main text.

2)  The authors affirm that “The nano zinc oxide particles have a particle size distribution of 20-30 nm, and these nanoparticles uniformly cover the surface of the whiskers.”; however, this information (in the Abstract it is specified 30 nm) does not appear so evident from the images in Fig. 1. Can they better explain, or provide more clear images supporting this size evaluation? Can they really talk about a “distribution” of sizes, and being reasonably sure that this is centered on 25 nm? Please explain much better or provide more quantitative, morphological data. Note that the ruler in the inset images of Fig. 1 is blurred and not visible. The distances D1 evidenced in Figure 1 are not mentioned in the main text, please explain.

3) Can the authors guarrantee that silver ion is incorporated instead of metallic silver?

Author Response

1)    There are mistakes/misleading sentences throughout the manuscript, for example: Lines (some)27, 41-42, 71, 146-147, 180, 189,…..the authors must carefully check for others and edit all the main text.

We are very sorry for our incorrect writing. We checked the full text and made changes.

2)    The authors affirm that “The nano zinc oxide particles have a particle size distribution of 20-30nm, and these nanoparticles uniformly cover the surface of the whiskers.”; however, this information (in the Abstract it is specified 30 nm) does not appear so evident from the images in Fig. 1. Can they better explain, or provide more clear images supporting this size evaluation? Can they really talk about a “distribution” of sizes, and being reasonably sure that this is centered on 25 nm? Please explain much better or provide more quantitative, morphological data. Note that the ruler in the inset images of Fig. 1 is blurred and not visible. The distances D1 evidenced in Figure 1 are not mentioned in the main text, please explain.

We are deeply sorry for our negligence. We have modified Figure 1 and in Figure 1(e) we can clearly see the size of the nano-zinc oxide particles.

3) Can the authors guarantee that silver ion is incorporated instead of metallic silver?

It can be confirmed that Ag is added to the reaction solution in the form of ions when synthesizing whiskers. And no characteristic peak of silver was found in the XRD pattern.

Reviewer 3 Report

The manuscript is interesting. The quality of the presentation should be improved. I suggest some improvements:

1. Results and discussion are not well presented as included in the same section, generating confusion to the readers. In particular, the section Discussions should be added, including a deeper comparison with the current state of the art. The section Results should be limited to data and figures.
2. Any limitations of the study should be also addressed in Discussions and reported in Conclusions.
3. Lines 223-224: Please, revise the statement limiting to the results achieved.
4. Line 209: Please, add a reference for the standard ISO 10993 and relative parts.
5. Abbreviation: missing definition for CCK-8 in the text.

Author Response

Manuscript revision instructions

Dear Editor Department of Coating Journal:

Hello! First of all, I would like to thank the reviewers for their hard work and valuable comments on this paper. After receiving your notice about the revision of the paper, we carefully analyzed and revised it. Please contact me if you have any questions.

1. Results and discussion are not well presented as included in the same section, generating confusion to the readers. In particular, the section Discussions should be added, including a deeper comparison with the current state of the art. The section Results should be limited to data and figures.

We have made correction according to the Reviewer’s comments. The literature is cited in the cytotoxicity section and XRD analysis section for comparison with this article. The antibacterial part adds the antibacterial mechanism of Ag.

2. Any limitations of the study should be also addressed in Discussions and reported in

Conclusions.

We are deeply sorry for our negligence. We have added content regarding the limitations of this experiment. First, there are certain limitations in the amount of silver ions incorporated. Secondly, silver ions have poor antibacterial properties against Staphylococcus aureus.

3. Lines 223-224: Please, revise the statement limiting to the results achieved.

We are deeply sorry for our negligence. We have supplemented Table 3.

4. Line 209: Please, add a reference for the standard ISO 10993 and relative parts.

We are deeply sorry for our negligence. The standard ISO 10993 has been listed in the references.

5. Abbreviation: missing definition for CCK-8 in the text.

We are deeply sorry for our negligence. cck-8 is the abbreviation of Cell Counting Kit-8 and has been annotated in the paper.

Reviewer 4 Report

The reviewer thanks the authors for submitting this work and the Editor for the invitation to review it. The reviewer feels that the paper is interesting, and it is within the Journal's scope.

 

Specific comments:

I congratulate the authors for the paper that is presented. But, please, see the following comments:

In the abstract: The connection among the three first statements of the abstract should be improved. In the last abstract statement, authors say that the modified Haw showed satisfactory antibacterial activity. This statement does not clarify what is considered satisfactory to the scientific community?

In section 1, The main question is related to the possible connection between this Haw modification and the final mechanical properties of the bone tissue repaired material. There is some possible linkage between these two issues?

In section 2, the statement that is previously to the cell viability formula needs to be improved. Moreover, the formula does not have a number associated. Hence, an equation number should be added. The section 2.5 needs careful revision also; please give a number to the equation presented at line 148.

The reference 22 was not cited within the paper. Would you please remove this reference or cite it?

In section 3, improve the legend of Figures 4 and 5, give more information related to the different label images.

Author Response

Manuscript revision instructions

Dear Editor Department of Coating Journal:

Hello! First of all, I would like to thank the reviewers for their hard work and valuable comments on this paper. After receiving your notice about the revision of the paper, we carefully analyzed and revised it. Please contact me if you have any questions.

1. In the abstract: The connection among the three first statements of the abstract should be improved. In the last abstract statement, authors say that the modified Haw showed satisfactory antibacterial activity. This statement does not clarify what is considered satisfactory to the scientific community?

We are deeply sorry for our negligence. The antibacterial rate of Ag-HAw was calculated, and

it was found that the antibacterial rate of silver ion to E. coli was above 90%. However, the

antibacterial rate of Ag-HAw against Staphylococcus aureus is not ideal. After modification

with ZnO, the antibacterial rate of Staphylococcus aureus was significantly improved, and the

antibacterial rate reached more than 84%.

2. In section 1, The main question is related to the possible connection between this Haw modification and the final mechanical properties of the bone tissue repaired material. There is some possible linkage between these two issues?

       The modified whiskers will affect the mechanics of bone tissue repair materials. Firstly, the

aspect ratio of the whiskers after silver modification is changed; secondly, after zinc oxide is

modified, it will adhere to the surface of the whiskers and play a certain pinning effect.

3. In section 2, the statement that is previously to the cell viability formula needs to be improved. Moreover, the formula does not have a number associated. Hence, an equation number should be added. The section 2.5 needs careful revision also; please give a number to the equation presented at line 148.

We are deeply sorry for our negligence. We have modified it and added a number to the formula.

4. The reference 22 was not cited within the paper. Would you please remove this reference or cite it?

We are deeply sorry for our negligence. I checked the article carefully and found that there is no reference [22], which has been deleted.

5. In section 3, improve the legend of Figures 4 and 5, give more information related to the different label images.

We have made correction according to the Reviewer’s comments. Figure 4 shows the different morphologies of cells on ZnO/Ag-HAw samples. Figure 5 has been annotated accordingly. (a, b, c, d, e) is the antibacterial result of Ag-HAw on E. coli; (f, g, h, i, j) is the antibacterial result of Ag-HAw on S. aureus; (k, l, m, n, o) is the antibacterial result of ZnO/Ag-HAw on E. coli; (p, q, r, s, t) is the antibacterial result of ZnO/Ag-HAw on S. aureus.