Bio-Entities Based on Albumin Nanoparticles and Biomimetic Cell Membranes: Design, Characterization and Biophysical Evaluation

Round 1

Reviewer 1 Report

Review of Marcela-Elisabeta Barbinta-Patrascu, Sorina Iftimie, Nicoleta Cazacu, Diana Lavinia Stan, Andreea Costas, Adriana Elena Balan, Claudia Gabriela Chilom’s manuscript entitled “Bio-entities based on albumin nanoparticles and biomimetic cell membranes: design, characterization and biophysical evaluation”

The article aims to produce protein-based particles by using bovine serum albumin dispersed in water and precipitated with ethanol or acetone later. UV-Vis absorption spectroscopy, Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) characterised the bovine serum albumin nanoparticles. The manuscript is interesting but needs to be improved.

Comments for the authors

1.     Please discuss the salting-out and sugaring-out effects in the introduction. You should discuss briefly the influence of vitamin C and glucose on these effects in the introduction and Results and Discussions parts. 

2.     Please carefully check the terminology. I do not agree with the word "synthesis" used to describe the production of BSA nanoparticles (line 156).

3.     Please add some references to prove that vitamin C and glucose can be used as reticulation agents. Or you should add more experimental results that could demonstrate this (lines 160-161, 167, etc.). Currently, the manuscript does not demonstrate any evidence that vitamin C and glucose induce cross-linking of bovine serum albumin nanoparticles.

4.     The scheme in figure 2 doesn't fully meet the description that is provided in lines 164-165. The stability test in figure 2 and the description are represented differently.

5.     Figure 3 isn't very informative.

6.     Any instrument you mention in the manuscript should contain full information: name, producer (city, country) (line 195).

7.     Please correct the temperature sign (lines 178, 191, and 218).

8.     Please check the magnification (line 227).

9.     Please add the reference and explain why you have chosen exactly this one excitation length.   

10.  Please check the meaning of the sentence (lines 245-246). dramatically modified?

11.  Please specify how much the absorbance of the sample decreased during 30 days period (lines 258).

12.  Please give some citations to prove the ability to crosslink glucose and vitamin C (line 275).  

13.  Please combine figure 6 and figure 7 into one figure.

14.  The descriptions of BSA NP production methods are difficult to read (lines 298, 337, etc.). I suggest you consider using the abbreviated notation BSA NP and numbering 1, 2, 3, ...

15.  Please use the same ratio indications of BSA NP: liposomes on an arrow as in the whole manuscript (figure 8B).

Author Response

Please find answers to your comments and suggestions in the attached document.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manu, a bio-strategy to design albumin-based soft materials based on albumin nanoparticles (BSA NPs), which is helpful for the development of novel drug carrier systems. The biomimetic membranes coated with BSA NPs layer presented nano-scale size and a (quasi) spherical morphology and characterized by AFM and UV-Vis. However, there is lack of enough direct evidence for their future applications.

Major points

Some experiments should be designed to identify the advantages of this soft material as a new drug carrier system or bio-coating system. For example, compare the effectiveness of DOX delivering with this material to other drug carrier systems. Otherwise, we cannot see the benefits of this material directly.

Minor points

1.       In the Introduction part, the description about desolvation is too much. Please condense it. And also the whole Introduction needs to be further simplified.

2.       The SEM images in the Fig 6 and Fig7C are not clear enough. Please provide another with better resolution. And it is suggested that the size distribution based on SEM results should be analyzed.

Author Response

Please find answers to your comments and suggestions in the attached document.

Author Response File: Author Response.pdf

Reviewer 3 Report

The author presented the paper "Bio-entities based on albumin nanoparticles and biomimetic cell membranes: Design, characterization and biophysical evaluation"

1) The reference list should be improved. Many more 2-3 years review papers should be cited in the Introduction section to show the progress in the area. I highly recommend not to use the references older 10 years for this section if it is possible.

May be these reviews suitable for your work 

https://www.mdpi.com/search?sort=relevance&page_count=50&year_from=2022&year_to=2023&subjects=med-pharma%2Cchem-materials%2Cbio-life&article_types=review-article&q=albumin+nanoparticles&view=default

Please, mention about EPR and albumin, and some more information about receptor interaction. May be this review may be suitable https://www.mdpi.com/2312-7481/8/2/13

2) The novelty of the work should be mentioned elsewhere (Introduction, Conclusion). There are many papers about albumin nanoparticles for various applications.

3) Is the method of albumin nanoparticle synthesis new (lines 156, 176, 189)? If not, please insert the reference in the experimental part. Have you studied the nanoparticle size in solution by dynamic light scattering?

4) Fig. 6 and Fig. 7C SEM images are very dark and poor. It is difficult to calculate the particle size. Please, present higher magnification pictures. Moreover, have you used dynamic light scattering to understand the sizes of particles in solution?

Please, enlarge Fig. 7A and 7B.

5) According to the literature data the size of nanoconstructions is optimal in the range from 20 nm to 200 nm (better 150 nm) (for in vivo applications). Too-high-sized nanoparticles (> 200 nm) do not pass through capillaries and tissue and vessel pores. However, in Figures 6 and 7 I see that the most of the particles have higher size. Can you calculate the size distribution? Please, present the size distribution for each synthesis method. For example, lower 200 nm 10%, lower 400 nm 20%, etc. Please, mention these limitations in the Conclusion section. Moreover, please explain how this high-sized system will work as a drug delivery system. Please, enlarge the discussion about it.

6) Fig. 9. It is difficult to understand the clear 3D dimensional sizes of nanoparticles and nanohybrids. Please present, the whole size of the constructs. I see only height, and it is higher 200 nm for nanohybrids.

Moreover, please present the discussion of your design in the text, may be with figure. Why you need such nanohybrids. Albumin can internalize cells in monomer and nanoparticles.

7) You haven't got any cell or biostability experiments (in salts, pH, media, etc.). In this way, I recommend presenting extensive discussion in the text that the presented systems will work with references.

Author Response

Please find answers to your comments and suggestions in the attached document.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

the required corrections of the manuscript were performed. 

Author Response

Thank you very much for your revision!

Reviewer 2 Report

 It’s very necessary to design experiments to compare the effectiveness of DOX delivering with this new material to other drug carrier systems, at least in some in vitro experiments. Just citing the references is not enough since this current new material is not exactly the same as the one addressed in the references.

Author Response

The response to your comment is detailed in the attached document.

Thank you for your suggestions to improve our article!

Author Response File: Author Response.pdf

Reviewer 3 Report

Thank you for the revised version.

Author Response

Thank you very much for your revision!