Antibacterial and Antifungal Silver Nanoparticles with Tunable Size Embedded in Various Cellulose-Based Matrices

Round 1

Reviewer 1 Report

The article entitled “Antibacterial and Antifungal Silver Nanoparticles with Tunable Size Embedded in Various Cellulose-Based Matrices” aims to use cellulose derivatives, silver nanoparticles (AgNPs) will be synthesized, and their antimicrobial properties evaluated. Several cellulose derivatives, like hydroxypropyl cellulose, methylcellulose, ethylcellulose, and cellulose acetate, can reduce and stabilize AgNPs. 

1-      The abstract should include some data, such as which cellulose derivative undergoes reduction and stabilization most effectively, and what is the silver particle size.

2-      My question is: Did the reduction of silver take place at room temperature????

3-      It is better to include standard deviations in tables 1 and 2

4-      Figure 6 is not clearly magnified

5-      It would be helpful for the readers if the author provided a picture of the antimicrobial activity of each cellulose derivative in the main text.

Author Response

Thank you for your time and for your considerations on the manuscript; they have been helpful in improving our work. All the changes made in the manuscript were highlighted in red.

1-      The abstract should include some data, such as which cellulose derivative undergoes reduction and stabilization most effectively, and what is the silver particle size.

Thank you for your observation. The following paragraph was included in the abstract:

It was found that using cellulosic derivatives, AgNPs with sizes ranging from 17 to 89 nm and different stabilities were obtained. The parameters such as: size and ζ potential indicate the stability of AgNPs, AgNPs-CA and AgNPs-HPC being considered more stable than AgNPs-EC and AgNPs-MC since they show higher ζ potential values.

2-      My question is: Did the reduction of silver take place at room temperature?

Yes, the formation of AgNPs by the reduction of silver ions to silver metal species was achieved in the presence of cellulose derivatives at room temperature over a period of 2 hours under vigorous stirring. Cellulosic derivatives can act as efficient reducing and stabilizing agents for the synthesis of silver nanoparticles.

 

3-      It is better to include standard deviations in tables 1 and 2.

We included in tables 1 and 2 the standard deviations. Thank you for your suggestion.

 

4-      Figure 6 is not clearly magnified

We replaced the image in the reviewed manuscript.

 

5-      It would be helpful for the readers if the author provided a picture of the antimicrobial activity of each cellulose derivative in the main text.

We included Figure 6 in the reviewed manuscript.

 

Reviewer 2 Report

Silver nanoparticles show promising application in antibacterial and antifungal field. In this manuscript, composite films are synthesized by using cellulose derivatives as effective reducing and stabilizing agents for AgNPs. The idea is interesting and the results are reliable. However, major revisions still required by following issues.

1.     “microscope” in “2.3. Scanning transmission electron microscope (STEM) and Transmission electron microscopy (TEM)” in line 176, 285, 286 should be revised as “microscopy”.

2.     “pictures” in line 178 should be replaced by “images”.

3.     It would be better to replace “lumps” in line 179 with “particles”.

4.     “transmission microscopy” in line 190 should be revised as “transmission electron microscopy”.

5.     Please pay attention to the writing of subscripts and superscripts.

6.     It would be better to add some data on the mechanical strength of the composite films if available. Please refer and cite “High Strength and Stable Proton Exchange Membrane Based on Perfluorosulfonic Acid/Polybenzimidazole”.

7.     Please do some comparison on the antibacterial and antifungal performance with other Ag composites.

8.     Green synthesis of silver nanoparticles is an interesting topic and many good papers have been published. Some close related references are suggested to be cited, for example “Preparation and properties of cellulose nanocomposite fabrics with in situ generated silver nanoparticles by bioreduction method; Nanocomposite egg shell powder with in situ generated silver nanoparticles using inherent collagen as reducing agent”.

Author Response

Thank you for your time and for your considerations on the manuscript; they have been helpful in improving our work. All the changes made in the manuscript were highlighted in red.

Silver nanoparticles show promising application in antibacterial and antifungal field. In this manuscript, composite films are synthesized by using cellulose derivatives as effective reducing and stabilizing agents for AgNPs. The idea is interesting and the results are reliable. However, major revisions still required by following issues.

1. “microscope” in “2.3. Scanning transmission electron microscope (STEM) and Transmission electron microscopy (TEM)” in line 176, 285, 286 should be revised as “microscopy”.

We corrected this aspect in the reviewed manuscript, “microscope” was corrected to “microscopy” in the manuscript.

 

2. “pictures” in line 178 should be replaced by “images”.

We corrected. Thank you for the observation.

 

3. It would be better to replace “lumps” in line 179 with “particles”.

We corrected. Thank you for the observation.

 

4. “transmission microscopy” in line 190 should be revised as “transmission electron microscopy”.

We corrected. Thank you for the observation.

 

5. Please pay attention to the writing of subscripts and superscripts.

Thank you for the observation. We revised the manuscript.

6. It would be better to add some data on the mechanical strength of the composite films if available. Please refer and cite “High Strength and Stable Proton Exchange Membrane Based on Perfluorosulfonic Acid/Polybenzimidazole”.

The mechanical properties of cellulose-based nanocomposites are very well documented in the specialized literature, it being well known that cellulose is an unbeatable material for making composites with remarkable mechanical properties. After reviewing specialized literature (for example, Carbohydrate Polymers 90 (2012) 1818-1825), we discovered that films made of composite materials based on cellulose derivatives have significantly improved mechanical properties like tensile strength, young modulus, etc. Moreover, the introduction of silver leads to both strengthening and toughening of the cellulose matrix. Similarly, other metallic nanoparticles–polymer nanocomposites could also be synthesized from appropriate metal salt precursors. This indicates the strong interactions between cellulose molecules and silver nanoparticles.

We introduced the reference recommended by reviewer.

Reference 30. Tang-Cheng Xu, Chang-Shui Wang, Zhao-Yu Hu, Jiao-Jiao Zheng, Shao-Hua Jiang, Shui-Jian He & Hao-Qing Hou

High Strength and Stable Proton Exchange Membrane Based on Perfluorosulfonic Acid/Polybenzimidazole.

Chin J Polym Sci 40, 764–771 (2022).

 

7. Please do some comparison on the antibacterial and antifungal performance with other Ag composites.

The availability of the agent in solution depends on the nature of the carrier molecule. Easier release of silver from the complex allows a fast antimicrobial effect at low concentrations. On the contrary, slow release requires higher concentrations for a comparable effect [ Burduniuc, O.; Bostanaru, A.C.; Mares, M.; Biliuta, G.; Coseri, S. Synthesis, Characterization, and Antifungal Activity of Silver Nanoparticles Embedded in Pullulan Matrices. Materials 2021, 14, 7041.].

 

8. Green synthesis of silver nanoparticles is an interesting topic and many good papers have been published. Some close related references are suggested to be cited, for example “Preparation and properties of cellulose nanocomposite fabrics with in situ generated silver nanoparticles by bioreduction method; Nanocomposite egg shell powder with in situ generated silver nanoparticles using inherent collagen as reducing agent”.

We introduced the reference recommended by the reviewer. Thank you for your suggestion.

Reference 10. Preparation and properties of cellulose nanocomposite fabrics with in situ generated silver nanoparticles by bioreduction method

Battu Deeksha, Vajja Sadanand, N.Hariram, Anumakonda Varada Rajulu

Journal of Bioresources and Bioproducts, Volume 6, Issue 1, February 2021, Pages 75-81

Reference 11. Nanocomposite egg shell powder with in situ generated silver nanoparticles using inherent collagen as reducing agent

Krittirash Yorseng, Suchart Siengchin, Basa Ashok, Anumakonda Varada Rajuluc

Journal of Bioresources and Bioproducts, Volume 5, Issue 2, May 2020, Pages 101-107

Round 2

Reviewer 1 Report

All queries were addressed by the author.

 

Ragab

Reviewer 2 Report

The manuscript has been well revised according to the comments and could be accepted now.