Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

The figures are too small, use the wrong aspect ratio and add nothing to the text.

The table is essentially unreadable in the format used.

You keep redefining acronyms all over the place.

 

Before one is allowed to inject a construct into a very sick patient one must pass an array of regulatory procedures that need to be held in mind before designing a construct.

• How do you synthesize, purify, load, store and transport the construct?

Seriously. At each stage you have to prove that you have a specific intermediate that can be quantified, and tested for both purity and heterogeneity.

Heterogeneity and measuring heterogeneity is hard, really really hard and the FDA demands that you quantify it. I spent 5 years developing and validating the homogeneity of a simple proteoliposomal system. You have just ignored this.

• How do you know that a specific surface protein being targeted is present in the tumor you are targeting?

Glioblastoma is highly heterogeneous across patients and inside the head of a single patient. You going to guess and keep your fingers crossed?

• In whatever media you store you drug loaded liposomes in there is going to be a huge concentration gradient, and it will leak. Some liposomes leak more than other, but all leak. The one type of lipid you never pick is saturated lipids like dipalmitoylphosphatidylcholine. Palmatate liposomes have huge temperature-sensitive transitions for moving from ice (synthesis and storage) to room temp makes them leak. They leak at body temperature. Liposomes are really tricky, and making them is not facile, and the choice of lipids and headgroups and ratios changes all the properties.
•  
• Blood contains glucose. Glucose is a reducing sugar and antooxidizes to make superoxide. This is converted into hydrogen peroxide. The steady state hydrogen peroxide level in blood varies in individuals but generally 5-15 µM.

You propose to use a Fenton-metal loaded liposomes inside people.

Only one oxyferryl formed by your magnets with endogenous peroxide is enough to initiate a free radical cascade in the bulk lipid and chew it up. There is a reason our lipid is filled with antioxidants.

• Imagine you heroically manage to make your constructs, and the FDA allows you to inject it into a patient. Can we ever place that patient in an MRI ever again?

We have patients with tattoos who bravely go into the coil even though they are in pain so we can get an image.

How do these tiny magnets, targeted to brain get cleared? How do we know they are cleared and that we can use the MRI again?

Comments on the Quality of English Language

The haphazard way you kept redefining acronyms all over the place was very annoying.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The overall research question is to propose a theoretical model for using nanoparticles embedded in PEG with ligands to interact with receptors on the membranes of glioma cells. These nanoparticles also contain superparamagnetic iron oxide. Once these nanoparticles bind to glioma cell receptors, an alternating magnetic field is applied to the patient's head, generating hyperthermia in glioma cells within the tumor and triggering the release of the nanoparticle's cytotoxic drug locally, but not in normal cells in the surrounding tissue. The article also reviews the clinical feasibility of this therapeutic application, including the challenges and limitations.

 

The article is a review and is relevant to the development of new therapeutics for treating glioblastomas. To treat glioblastomas, there are two challenges: (1) the passage of drugs or therapeutics through the blood-brain barrier, and (2) the selective targeting of therapeutics to glioma cells but not the normal brain cells. The article review fills this gap by overcoming both challenges. These nanoparticles can cross the blood-brain barrier and bind to receptors on glioma cells, thereby targeting them. Significantly, the drug cargo is released only in glioma cells by alternating magnetic fields that trigger localized hyperthermia. Thus, the article provides details of theoretical experiments aimed at overcoming both problems.

 

Several labs have published on the use of nanoparticles that carry drug cargo and can pass through the blood-brain barrier. Unlike other research, this article reviews a new technology for local hyperthermia that increases tumor temperature to 42 degrees Celsius to promote drug release.

 

Overall, the article is a review and does not include an experimental section because no experiments were conducted for this review.

 

Based on a review, the article's conclusion is consistent with the information presented by summarizing an overall review of a theoretical model regarding an application of nanoparticles that can have several layers of functionality, i.e., carry ligands and exhibit superparamagnetic properties, used for local drug release via hyperthermia. However, the article notes that experimental validation is needed. Overall, the main question or central focus of the review has been addressed through the details of this nanoparticle technology, including challenges and feasibility.

 

The references are appropriate, covering previous experiments of overcoming the blood-brain barrier and previous drug delivery methods. Fifty-six references provide a focus on the subject. 

 

The tables and the figures are appropriate. However, the font in figures 2 and 4 needs to be increased.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents a comprehensive and timely review of ligand-functionalised, magnetic lipid nanoparticles for glioblastoma therapy, providing a conceptual design framework for future research and clinical translation. The writing is clear, the figures and tables add value, and the modular approach is well-justified. However, several points require clarification, additional evidence, and more explicit discussion of limitations, translational hurdles, and recent clinical advances.

 

1. Abstract & Simple Summary

Suggestion: The abstract effectively summarizes the concept but would benefit from a brief sentence on recent advances and clinical translation of magnetic nanoplatforms for GBM. Please also briefly mention key challenges such as heterogeneity and manufacturing.

Suggested edit: Add after line 39: “Despite promising preclinical results, clinical translation of these systems faces significant hurdles including patient-specific heterogeneity and large-scale manufacturing.”

2. Introduction – Clinical Context and Unmet Needs

Clarification Needed: The introduction highlights the barriers well, but lacks details on the current clinical status of nanomedicine in GBM and how the proposed platform improves upon existing options.

Suggested edit: After line 66, add a short paragraph summarizing recent clinical trials of nanocarriers in GBM (e.g., NBTXR3, NEO100) and their limitations, to contextualize the need for MF-R-LNs.

3. Figures & Schematics

Suggestion: The figures are valuable but lack scale bars or size indications. In Figure 2, please indicate typical nanoparticle sizes (e.g., “80–150 nm”) for clarity.

Suggested edit: Revise figure legends at lines 168 and 268 to include particle size and composition.

4. Targeting Ligands Table – Clinical Translation

Limitation/Clarification: Table 1 is excellent, but should highlight which ligands have reached clinical trials in brain cancer or are approved for human use, and indicate potential immunogenicity/biocompatibility issues.

Suggested edit: Add a column: “Clinical status/notes” indicating FDA-approved, Phase I/II, or preclinical only.

5. Heterogeneity and Personalization

Expansion Needed: The manuscript rightly emphasizes the need for multi-targeting due to GBM heterogeneity, but does not provide actionable recommendations for personalized ligand selection or companion diagnostics.

Suggested edit: At line 243, add: “Future designs may benefit from integrating tumour biopsy profiling or liquid biopsy approaches (e.g., circulating tumour DNA, exosomes) to inform ligand selection for personalized MF-R-LNs.”

6. Stimuli-Responsive Release – Recent Literature

Suggestion: The discussion of stimuli-responsiveness would benefit from more recent literature, especially on dual/multi-responsive systems for GBM. Cite 2023–2024 studies if possible.

7. Manufacturability and Regulatory Aspects

Expansion Needed: Discuss regulatory challenges (e.g., PEG immunogenicity, SPION safety, nanoparticle tracking) and the current status of GMP-grade manufacturing for these systems.

Suggested edit: Expand lines 252–253 with a paragraph: “Translation to clinic will require addressing regulatory concerns such as the ‘PEG dilemma,’ standardizing SPION characterization and MRI tracking, and ensuring scalable GMP-compliant manufacturing protocols.”

8. Magnetic Hyperthermia – Practical Parameters

Suggestion: The section would be strengthened by specifying recommended magnetic field parameters (frequency, amplitude) used in successful preclinical GBM studies, and briefly discussing safety limits.

Suggested edit: After line 280, add: “Typical alternating magnetic field parameters for SPION hyperthermia are 100–500 kHz at <15 kA/m, with safety limits to avoid non-specific tissue heating.”

9. Clinical Translation and Limitations

Expansion Needed: The manuscript briefly mentions translational hurdles, but these deserve a dedicated section near the conclusion. Discuss in detail:

Tumour heterogeneity , Safety/immunogenicity , Scalable manufacturing

Regulatory approval and clinical trials , Limitations of current preclinical models

Suggested edit: Add a new subsection before the conclusion (e.g., “Translational Barriers and Future Directions”).

10. References

• Update Needed: Several references in Table 1 and the stimuli-responsive section are pre-2022. Please update with the latest reviews and key experimental studies from 2023–2024 to maintain currency.

 

Line 56: “One of the most significant obstacles…” — Please cite a recent review (2023–2024) to support this statement.

Line 86: “ligand heterogeneity” — Typo, should be “ligand and receptor heterogeneity.”

Line 107: “elevated interstitial fluid pressure (IFP)” — Briefly quantify typical IFP in GBM vs. normal brain.

Line 188: “PEGylation improves stealth properties…” — Cite recent work on the “PEG dilemma” and anti-PEG antibodies.

Line 240: “builds should favour multi-target redundancy”—awkward phrasing; consider rewording for clarity.

Comments on the Quality of English Language

 The English could be improved to more clearly express the research.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Author responses are sufficient