Application of the Integrated Supercritical Fluid Extraction–Impregnation Process (SFE-SSI) for Development of Materials with Antiviral Properties

Round 1

Reviewer 1 Report

Reviewers' comments:

Manuscript Number: processes-1635880

Title: Application of the integrated supercritical fluid extraction-impregnation process (SFE-SSI) for development of materials with antiviral properties

The MS deals with the application of the integrated supercritical fluid extraction-impregnation process for the development of functionalized material with antiviral properties. The work is interesting since it is reporting the application of active compounds containing material for antiviral properties. I feel that the paper in the present form lacks the quality needed for this journal, and key experiments /details are missing. However, I have several significant concerns to be addressed, my comments and suggestions are listed below:

English editing is needed for this manuscript. Several statements should be re-written, Authors have to carefully check the English grammar throughout the manuscript.

Comments

• Line 19-20: Integrated supercritical fluid extraction-impregnation process (SFE-SSI) was performed to fabricate of the material with antiviral properties against Herpes Simplex Virus (HSV). Revise the sentence.
• Line 22, 24,145, etc: Melissa officinalis, italicize the scientific names, throughout the manuscript.
• Materials and experimental section (for eg: section 2.2,) should be improved by providing the quantitative information used in this study in detail for easy reproducibility. More details, including the specific masses of samples/components and volumes of each liquid, need to be specified.
• Section 2.8: author should provide the detailed protocol with the quantity of the material used for the preparation of different concentration (mention the highest conc to lowest conc tested) used for the analysis.
• Line 496-497: In result and discussion: the presence of the virus in the inoculated RK-13 cell lines was not observed. Author should provide some images or data/graph which support the antiviral properties of the materials. Lack of supporting data for the antiviral activity.
• Line 130: Please always leave a space between number and SI unit (e.g. 3h, etc.), however no space before the "%", "/" and ":" signs.
• Line 127: 280 ml change to 280 mL
• Line 128: section 2.3.1 - laboratory scale unit of the combined SFE-SSI process – provide the model name and no, including the manufacturer details.
• Line 149: 100 ml change to 100mL, check throughout the manuscript.
• Line 162: mentioned as 2 hours and in line 160 as 5 h. the unit should be mentioned in S.I unit throughout the manuscript.
• Line 164: 10 g/min for 5 minutes. Change to S.I unit
• What will be the size and structure of the materials after impregnated and how it will be the final sample? Author should provide the image of the samples (M. officinalis impregnated materials like cotton gauze and SCF film).
• In result and discussion: Author should improve the result and discussion part by explain the results in detail for better understanding.
• Include more relevant references and discuss, elaborately.

For eg: Perumal et al., 2016; Antifungal activity of five different essential oils in vapour phase for the control of Colletotrichum gloeosporioides and Lasiodiplodia theobromae in vitro and on mango

Perumal et al., 2017; Effects of Essential Oil Vapour Treatment on the Postharvest Disease Control and Different Defence Responses in Two Mango (Mangifera indica L.) Cultivars

Perumal et al., 2021. Preparation and characterization of a novel green tea essential oil nanoemulsion and its antifungal mechanism of action against Magnaporthae oryzae. Ultrasonics Sonochemistry, 76, 105649.

Perumal et al., 2022; Application of essential oils in packaging films for the preservation of fruits and vegetables: A review.

• Line 208: PTFE, provide the full form at the first place.
• Line 214, provide the name of the standards used in the study.
• In fig 1, in y axis, y denotes what?
• Line 366-389: the content is repeating, delete it.
• Line 512: in vitro – italics.

Author Response

The authors would like to thank the Reviewer for constructive comments and suggestions. Responses to the issues raised are given in the attached “Detailed responses to Reviewer 1” file and changes in the manuscript made during the revision process are marked red.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In this work the authors investigate the use of supercritical CO2 to extract some essential oils from a natural material and achieving their incorporation into cotton or into a starch/chitosan polymer film. The authors integrated two commonly employed supercritical techniques, i.e. SFE and SSI, into a single integrated process. This approach has not been investigated in the literature extensively and is the main novelty of the work. The paper is clearly written (some typos and grammar mistakes require correction, so I recommend an accurate revision!) and the results are interesting and clearly discussed. I recommend the paper for publication after the following minor point are addressed:

• Line 20. “to fabricate a material”
• Line 70. “high quality materials”
• Specific references reporting examples of previous uses of the SFE process are missing. I recommend the authors to add some reference to specific review papers. If the authors wish they can add the following ones: https://doi.org/10.1016/j.mset.2019.04.005; https://doi.org/10.3390/molecules22071186
• As far as SSI is concerned, the authors report some appropriate references related to the incorporation of essential oils into different materials. Since this technique is widely employed and covers different research areas and applications I suggest the authors to add some references to recent review papers that discuss this technique, such as https://doi.org/10.1002/star.201500194; https://doi.org/10.1016/j.tifs.2022.01.025; https://doi.org/10.3390/ph14060562; https://doi.org/10.3390/polym13050729;https://doi.org/10.1016/j.jconrel.2015.05.002. Furthermore, also supercritical fluid dyeing can be considered an SSI technique and since the authors investigate the impregnation of cotton, which is a textile material, a reference to some recent review papers on this aspect could also be added (if the authors wish).
• Section 2.3. When I read this section I wandered how the working temperature, pressure and flow rate of the SFE process had been selected. The answer is reported in section 3.1. However, I suggest the authors to report a sentence in section 2.3 that clarifies this point to the reader. A short sentence reporting that the explanation of the working condition selection is discussed in section 3.1 may be enough!
• Section 2.4. I suggest the authors to report a scheme of the integrated-SFE-SSI apparatus. This would help the reader better understand how experiments were conducted. For example, are two pumps present in the apparatus? I mean a pressurization pump and a recirculating one. This point is not very clear. A figure would help…
• Section 3.2. Lines 366-389 have to be removed since they are the exact repetition of lines 342-365!!!

Author Response

The authors would like to thank the Reviewer for constructive comments and suggestions. Responses to the issues raised are given in the attached “Detailed responses to Reviewer 2” file and changes in the manuscript made during the revision process are marked red.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

In this paper, the authors used an integrated process based on the use of supercritical carbon dioxide to obtain a film charged with antiviral materials. The paper is interesting and can be published after some revisions.

There are some typos and mistakes. Please read the paper again or ask the help of a mother tongue colleague. Just a few examples:

• Melissa officinalis has to be always written using the italic font.
• Line 20: correct “to fabricate of the material”
• Line 103, line 220: use the superscript for cm2 and cm-1
• Line 147: described is misspelled
• Line 174: Use the subscript for mi
• Line 175: please, don’t use the bold font for the equation
• Line 372: please rephrase “further increase increased”

The authors used “impregnation” in some parts of the paper and “adsorption” in other parts of the paper. Please, choose one of them and use it throughout the article to avoid misunderstanding for the readers.

Many active principles have been impregnated using supercritical impregnation onto films for different applications. Please expand the study of the literature regarding this process in the introduction. See, for example,  Liparoti et al (10.1016/j.supflu.2021.105411), Bastante el al (10.1016/j.foodhyd.2021.106709), Franco et al (10.1016/j.jcou.2019.06.012).

Please add a ref for subsection 2.2.

Lines 136-138: how the operating conditions have been chosen? Please, justify or add a ref.

Line 207: please explain what NKE, G/1 and F/2 are.

Lines 378-380: I can’t entirely agree with the two different mechanisms. The first one is not an impregnation: it is a deposition onto the surface. If the dissolution profile had been evaluated, the surface material would have been released immediately (there would have been an initial release burst), so it cannot be considered impregnated material but only resting on the film.

Author Response

The authors would like to thank the Reviewer for constructive comments and suggestions. Responses to the issues raised are given in the attached “Detailed responses to Reviewer 3” file and changes in the manuscript made during the revision process are marked red.

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have responded to all the comments. however, the quality of Figure 5 is not good, so please improve it.

Reviewer 3 Report

In my opinion, the paper can be accepted in the current form