Effective Use of Euphorbia milii DCM Root Extract Encapsulated by Thermosensitive Immunoliposomes for Targeted Drug Delivery in Prostate Cancer Cells

COMMENTS

RESPONSE

REVIEWER 1

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

Title needs to be revised to show Euphorbia Milii extract

The title has been revised accordingly

Abstract, please make it a complete paragraph. “The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings”. The author only mentioned EME and docetaxel-loaded liposome in the abstract, however, doxorubicin’s data was also included.

Abstract rephrased to a single paragraph following the style of structured abstracts without headings.

Doxorubicin is now mentioned in the abstract

 The introduction is vague and needs to be extended. For example, it is necessary to briefly compare the advantages and disadvantages of liposomes with other nanocarriers. What is the motivation for using Euphorbia Milii extract? What is the strategy for targeted delivery used in this report?

The introduction has been revised stating advantages and disadvantages of liposomes with other nanocarriers.

The motivation for using Euphorbia milii stems from previous reports about anticancer potential of the plant and very limited studies on its use against prostate cancer.

The target strategy employed was the conjugation of the PSMA to the liposomes to have a controlled release. The attachment of specific antibodies to the surface of the liposomes makes it possible for them to bind to cells and subsequently be internalized by the cells.

There are no Materials and Conclusion Sections.

Materials and Conclusion sections are now added

The author introduced leaves, roots, and stems extracts with different organic solvents. However, it is unclear which extract was used to load into liposomes.

The DCM root extract was loaded in the liposomes. This was mentioned in the abstract, in section 2.3 when investigating the Cytotoxic activity of docetaxel-loaded liposomes and EM liposomes, in the results section it was mentioned that DCM root extract was the only active extract.

This has now been added in section 2.4 synthesis of heat sensitive liposomes.

 Section 3, the writing “Figure x …..”, such as, “Figure 2 Growth inhibition of LNCap cells when treated with…” is awkward. Figure 3 has not been mentioned. The text in this section mainly describes the Figures without discussion or conclusion

Figure labels have been removed.

Text for figure 3 has been included

Text in the results section provides an analysis of the results.

Section 3.4, FTIR measurements of the EME, doxorubicin, and docetaxel-loaded liposome do not provide any meaningful insight since these samples are very complex. For example, the EME-loaded liposome might contain many compounds from the extract, liposome components, and the anti-PSMA antibody. Doxorubicin-loaded liposome is without the complexity of the EME, and yet has a spectrum very similar to EME-loaded liposome. On the other hand, docetaxel-loaded liposome has a completely different spectrum compared to doxorubicin-loaded liposome. These results need clarification.

We would like to thank you for your thoughtful and constructive feedback on the FTIR results. FTIR spectrometry was used to examine the interaction between drugs     and temperature-sensitive immunoliposomes. The FTIR results of both EM and doxorubicin-loaded heat-sensitive immunoliposomes were similar, indicating that   the liposomal encapsulation of drugs did not result in the formation of new linkages. However, this was different for docetaxel, as different peaks were observed for the docetaxel-loaded heat-sensitive immunoliposomes. We have decided to exclude these results as they are redundant in this study.

No particle can be spotted in TEM images (Figure 9A and B) and SEM images seem not to show spherical shape as mentioned. DLS measurement is important to assess the size distribution

The SEM and TEM images are similar to those previously reported in research conducted using liposomes.(Quan et al., 2020, Chen et al., 2017, Grace et al., 2021).

The suggested experiment to determine the size distribution have been noted as a limitation of this study and has now been recommended

Section 4, “The IC50 were calculated to be 8.44 ug/ml and 11.74 ug/ml for liposome encapsulating the plant extract and docetaxel drug, respectively.” Free docetaxel showed higher toxicity than EME as shown in Figure 3, 4, and 5. Why EME-loaded liposome show higher toxicity than docetaxel-loaded liposome under the same triggered release condition

Research has shown that encapsulating plant extracts within conjugated liposomes can increase their activity . (Yılmaz et al., 2023)

Section 2, the preparation of liposomes should be moved prior to the characterization of its cytotoxic activity.

The preparation of liposomes is now moved prior to the characterization of its cytotoxic activity

Section 2.8.4, there is no description for docetaxel-loaded liposome

This has now been added

English writing must be improved. Other errors, such as, missing a space (“oftarget”, “spectrophotometerwas”, etc.), use of an abbreviation before its definition (SEM, TEM, FTIR, etc.), missing a unit, such as cm^-1 in section 3.4.

Typos corrected,

Abbreviation use corrected

Paper to be sent for CIMB English editing

Missing unit has been added to section 3.4

REVIEWR 2

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

I believe that this work in its current state is not suitable for publication. First, it is necessary to review all the figures that need to be improved in their representation. For example, for figures 9 and 10 the letters must not be written freehand.

Figures have been improved

It is necessary to redo tables 3 and 4, perhaps following the style of table 2.

Tables have been revised following MDPI CIMB style

Furthermore, it is important to carry out further studies, particularly for the characterization of liposomes such as DLS analysis to determine the average size, polydispersity index and surface charge. Furthermore, it is also important to study the release profile of the encapsulated drug over time.

The suggested experiments are noted for further studies in our laboratory but as limitations of the reported study and has now been included as recommendation.

REVIEWER 3

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

Introduction. The introductory part is not sufficient. Many studies using the mentioned plant extract and the nanoparticle have been conducted. It should be expanded and list literature data for initial comparison.

Introduction has been revised to incorporate other studies on the plant and nanoparticle.

Ethanol is safer solvent. The author should provide a reason why not ethanol for further use.

A lot of research on this plant has been conducted with ethanol extract, but not on the solvents we used to investigate the plants cytotoxic activity, and phytochemicals of this plant. Our current study provided new information on other solvents extracts of the Euphorbia milii plant.(Patil, 2020, Negm et al., 2024)

3. 2.1 Phytochemical analysis. The methods used for these analyses should be described in detail. The dosage of plant powder should be quantified for each assay.

The methods used for phytochemical analyses are now described in detail. The dosage of plant powder is also added for each assay.

 Figures and Table did not be prepared as in mdpi style.

Tables and figures have been revised in line with MDPI style.

5. All figures’ qualities did not reach the publication level. The word style (italic or not), size should be consistent.

Figures quality have been improved and now publishable.

Word style and size are now consistent.

6. Typos should be fixed.

Typos have been fixed. Paper to be sent for language editing

7. The discussion must be refined and more significantly connected with the obtained results.

Results of this study are stated, analyzed and compared to other studies in the discussion

COMMENTS

RESPONSE

REVIEWER 1

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

 The author removed all of the figure captions. Figure captions must be added.

The figure captions were removed as per comment provided by one of the reviewers. Recently published articles by the CIMB journals were reviewed and they do not have figure captions https://doi.org/10.3390/cimb46080523

https://doi.org/10.3390/cimb46080522

https://doi.org/10.3390/cimb46080519

Editing of English language required. There are many uncompleted sentences and other gramma errors. For example, “In Figure 1 (c), growth inhibition of DU145 cells by root extracts of EM.” “Figure 2 Growth inhibition of LNCap cells when treated with different concentrations (100, 10, and 1 μg/mL) of DCM root extract of EM.” Section 3, describing the results should be a complete paragraph. Sometimes, I am not sure if the text is the discussion of the results or the figure caption, for example, figures 2-5.

Manuscript has been sent for English language editing. Uncompleted sentences have been completed and grammar errors have been revised

The text describes and discusses the figures.

What does this sentence mean? “DCM root extract showed more than 50% activity at 1µg/ml, 10µg/m and 100µg/ml concentrations, inhibiting 67.51 ± 8.3% of the cells (IC50).” How is “inhibiting 67.51 ± 8.3% of the cells” IC50?

The sentence means that the DCM root extract of Euphorbia milii plant was active at all 3 tested concentrations. The percentage inhibition at 1µg/ml was 50.1%, at 10µg/ml was 67.51% and at 100µg/ml was 82.2%. All these concentrations are above 50%

8.3% is the standard deviation recorded at that concentration

I do not agree with the author’s response on the TEM images due to the fact that there is no particle can be spotted in Figures 6a and b. Most obviously, nothing can be observed except the see-through circles in Figure 6b, which should not be the liposome particles as indicated by the author. If the particles are there, please indicate by an arrow. What does it mean by “…images… at 50nm,100 nm, 500 nm, and 1 micrometer.”? 50nm/100 nm/500 nm/1 micrometer is the scale bar of the image. In figure 6a and b, the images with 50 nm scale bar were put on the left-hand side while it was put on right-hand side in figure 6c. The scale bars of Figures 6 and 7 are blurred and unreadable. Please update

Liposomes containing metal substances usually contain black particles inside, however liposomes containing drugs usually appear see through and spherical under and TEM.

The cited paper below shows similar TEM images of Docetaxel liposomes appearing see through and spherical

https://doi.org/10.2147/DDDT.S149620

50 nm,100 nm, 500 nm, and 1 micrometer is the microscope magnitude the liposomes are viewed at.

TEM images at 50 nm put-on right-hand side and 100 nm on left side

Quality of the figures now improved  

Table 2, what is “EME 1.41” and “Standard drug 1.774”. Table 2 and 3 were not mentioned in the text. In table 3, the unit for “calculated concentration” should be “ppm” instead of “rpm”? Why does it indicate 0 ppm in the table but mention 0.607 ppm in the text?

The absorbance read from the micro plate reader of the E. milii and the standard drug samples at 526 nm is 1.14 and 1.774 respectively

Unit corrected

The concentration of doxorubicin was calculated as 0.607 ppm, this was a typographical error while updating the table to MDPI CIMB style

For Table 4, how do the authors define “EME RELEASED”, “EME ENCAPSULATED”, “DOC RELEASED”, “DOC ENCAPSULATED”? This sentence should be rewritten “The concentration of docetaxel detected when the drug was released was found to be 9 ug/ml and when liposomes were not exposed to 40°c hyperthermia the concentration was found to be 5.6 ug/ml.” How about doxorubicin? Please only use ppm or µg/ml.

EME RELEASED” and “DOC. RELEASED”, these are the samples of the Euphorbia milii extract and Doc. encapsulating liposomes analyzed when the liposome was exposed to heat releasing the EME and DOC, “EME ENCAPSULATED” and “DOC ENCAPSULATED” sample of Euphorbia milii extract and Doc. liposomes analyzed when liposome was not exposed to heat”,

Text updated from EME released to free EME (the sample of EME released from liposomes when exposed to heat)

EME ENCAPSULATED updated to EME ENCAPSULATED liposomes

Doc. released updated to Free Doc (the sample of docetaxel released from liposomes when exposed to heat)

DOC. ENCAPSULATED updated to DOC ENCAPSULATED liposomes

Doxorubicin was used as a control- as mentioned in the text the concentration of doxorubicin (0.607 ppm) and was used as a reference to calculate the concentration of EME considering the area of the peak of the EME

ppm changed to µg/ml

The presentation of “The weight of liposomes” is incomprehensible. How is 4.3 mg = 2.15 mg or 4.3 mg = 2.15 mg x 0.5 mg? I am not sure what the authors would like to show here. Loading efficiency and loading content should be evaluated instead.

the weight of liposomes was found to be:

EME encapsulating liposome 4.3 mg =2.15 mg (0.5mg drug added). Docetaxel encapsulated liposomes 4.5 mg =2.25mg (0.5mg drug added). 

Calculating Concentration of drug inside liposomes. The concentration was found to be 839 μg/mL in a sample of 0.5mg of drug   added.”

This experiment aimed to show the weight of the liposomes. EME encapsulating liposomes was weighted and found to be 4.3 mg. These liposomes were then divided into two (liposomes that will be exposed to heat during experiments, and liposomes that will not be exposed to heat and this was 2.15 mg each). (0.5mg drug was added in each sample). 

Docetaxel encapsulated liposomes were weighed and found to be 4.5mg. These liposomes were then divided into two (liposomes that will be exposed to heat during experiments, and liposomes that will not be exposed to heat and this was found to be 2.25mg (0.5mg drug was added in each sample). .

Sample of drug added have been removed to make this paragraph easy to read and understandable.

The use of “exposure to hyperthermia” or “hyperthermia” should be avoided, try “exposed to heat”, or “heat”

Exposure to hyperthermia replaced to exposed to heat

  Typos, “concentration", “samplesa”. Please carefully check throughout the manuscript.   Typos, “conceentration", “samplesa”. Please carefully check throughout the manuscript.;

Typos corrected

COMMENTS

RESPONSE

REVIEWER 2

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

Advice the authors to improve the Figure7.

Figure 7 improved

REVIEWER 1

We would like to express our sincere gratitude for your thoughtful and constructive feedback on our manuscript. Your insights and suggestions have been immensely valuable in improving the quality of our work.

About the Figure caption, please see the instruction about preparing Figures, Schemes and Tables of CIMB. In addition, the articles provided by the authors have captions. I believe that the current representation is awkward and not suitable for publication as a research article. THIS MUCH BE REVISED.

 Figure captions have now been added

My previous comment “What does this sentence mean? “DCM root extract showed more than 50% activity at 1µg/ml, 10µg/m and 100µg/ml concentrations, inhibiting 67.51 ± 8.3% of the cells (IC50).” How is “inhibiting 67.51 ± 8.3% of the cells” IC50?” In this sentence, the inhibition of  67.51 ± 8.3% belong to which concentration? The author did explain in their answer that “The percentage inhibition at 1µg/ml was 50.1%, at 10µg/ml was 67.51% and at 100µg/ml was 82.2%.” However, it has not been clarified in the manuscript. The next thing is how is “inhibiting 67.51 ± 8.3% of the cells” IC50? IC50 is a concentration that inhibit 50% of cells. Hence, 67.51 ± 8.3% is not a concentration in order to be marked as IC50. Why 67.51 ± 8.3% is mentioned, not the 1µg/ml which inhibited 50% of cells? THIS MUCH BE REVISED

The sentence has been revised to reflect the intended meaning.

The percentage inhibitions at the three concentrations stated have been clarified in the manuscript.

About the TEM images, it may be correct as the author mentioned that “liposomes containing drugs usually appear see through and spherical under and TEM” as well as in the cited paper. However, the images provided in Figure 6 did not show this clearly. In addition, the author mentioned that “50 nm,100 nm, 500 nm, and 1 micrometer is the microscope magnitude the liposomes are viewed at.” What is microscope magnitude? I believe that the authors mean magnification. What is it even mean to have 50 nm,100 nm, 500 nm, and 1 micrometer microscope magnitude or magnification? In the TEM, SEM or microscope images, it is required to have a scale bar where 50 nm,100 nm, 500 nm, or 1 micrometer were put next to it to indicate their correspond size. In the new TEM images, the author removed all of the scale bar. In the SEM images, the text is not readable. In addition, all the text discussing the “microscope magnitude” should be modified. THIS MUCH BE REVISED.

TEM and SEM images have been improved by separating the images as combining the images into one affects the quality.

The wording has been corrected, 50 nm,100 nm, 500 nm, and 1 micrometer  is the scale not “microscope magnitude”

The scale bars have been added again as suggested. The texts in the SEM images are now readable. All the text discussing microscope magnification have been modified as indicated.

Many thanks for your contributions.