Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript provides a comprehensive and timely analysis of the "innovation hunger" in antifungal therapy and explores the potential of lipid-based drug delivery systems (LDDSs) to overcome antifungal resistance. The integration of recent clinical data (2022–2023) and deep molecular mechanisms of resistance (especially concerning C. auris) is a significant strength. The work is well-written and holds substantial value for both mycologists and pharmaceutical scientists.

However, I have a few comments to improve the clarity:

• Currently, Chapters 2 and 3 have identical titles ("Antifungal drugs: Mechanisms, Spectrum, and Emerging Resistance"). This is unacceptable for a scholarly review. I suggest differentiating them: e.g., Chapter 2: "Conventional Antifungal Classes" and Chapter 3: "Novel Antifungal Agents and Natural Products."
• The authors mention Ibrexafungerp in Section 3.1 among experimental agents. However, as an FDA-approved drug (2021), it should be moved to Section 2.6 (Triterpenoids) to join the established drug classes. Chapter 3 should be reserved strictly for agents in clinical trials (e.g., Fosmanogepix, Olorofim).
• Visual Representation (Proposed Schemes): To significantly enhance the impact of the review, I highly recommend adding two new visual elements:
1. A figure illustrating the general chemical structures and schematic mechanisms of action for each drug class (including the drug-target interaction).
2. A comparative scheme or structured table for the "Advantages and Disadvantages" section (Section 6), allowing a side-by-side comparison of LPs, SLNs, NLCs, and LNPs.
• Liposomes must be consistently integrated into the general definition of LDDSs throughout the manuscript (especially in the abstract and Section 3.4), rather than being treated as a separate entity from "lipid nanoparticles."
• Polyenes: In Section 2.3, I suggest mentioning the sterol sponge model alongside the classical pore-forming mechanism, as it represents current understanding of Amphotericin B activity.
• Oteseconazole: Clarify that its primary clinical breakthrough is oral administration for recurrent infections, not just topical use.
• In Section 5.1, explicitly state that drug expulsion in SLNs is driven by the transition of lipids to the stable β-polymorphic form.
• The MIC Paradox: In Section 5.6, the authors correctly note that sustained release can lead to higher MICs in vitro. I recommend suggesting time-kill kinetics assays as a more accurate method for evaluating the efficacy of LDDSs compared to endpoint MIC testing.
• Use fungal-specific terms like Cdr1/Mdr1 transporters instead of the mammalian 'P-glycoprotein' in the context of fungal efflux.
• I suggest mentioning the potential of enzyme-triggered release (responsive to fungal lipases/proteases) and theranostic LDDSs to further strengthen the "Future Perspectives" section.
• Please correct "ketoconazol" to "ketoconazole", "terbinafineand" to "terbinafine", "polidispersity" to "polydispersity", and "stablished" to "established".
• Please find my detailed, line-by-line recommendations and specific technical comments in the attached Word file.

The manuscript is of high quality and offers a sophisticated bridge between pharmaceutical technology and clinical mycology. Once the structural inconsistencies are addressed and visual aids are incorporated, this review will be a valuable addition to the literature.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The quality of the English language is generally high; the manuscript is well-structured and uses appropriate technical terminology. However, there are minor grammatical inconsistencies, several typographical errors in drug names, and occasional issues with subject-verb agreement. A thorough proofreading is recommended to polish these minor linguistic flaws before publication.

Author Response

Comments 1: [Currently, Chapters 2 and 3 have identical titles ("Antifungal drugs: Mechanisms, Spectrum, and Emerging Resistance"). This is unacceptable for a scholarly review. I suggest differentiating them: e.g., Chapter 2: "Conventional Antifungal Classes" and Chapter 3: "Novel Antifungal Agents and Natural Products."]

Response 1: We thank the reviewer for pointing out this issue and apologize for the oversight, which occurred during the manuscript formatting process. The title of the Chapter 3 has now been revised to “New Strategies to Overcome Antimicrobial Resistance Mechanisms” to crearly differentiate it from Chapter 2. This change has been implemented in the revised manuscript.

 

Comments 2: [The authors mention Ibrexafungerp in Section 3.1 among experimental agents. However, as an FDA-approved drug (2021), it should be moved to Section 2.6 (Triterpenoids) to join the established drug classes. Chapter 3 should be reserved strictly for agents in clinical trials (e.g., Fosmanogepix, Olorofim).]

Response 2: We thank the reviewer for this important observation. We agree that Ibrexafungerp, as an FDA-approved drug, should be classified among established antifungal agents. Accordingly, it has been moved from Section 3.1 to Section 2.6 (Triterpenoids) in the revised manuscript.

 

Comments 3: [Visual Representation (Proposed Schemes): To significantly enhance the impact of the review, I highly recommend adding two new visual elements:

A figure illustrating the general chemical structures and schematic mechanisms of action for each drug class (including the drug-target interaction).

A comparative scheme or structured table for the "Advantages and Disadvantages" section (Section 6), allowing a side-by-side comparison of LPs, SLNs, NLCs, and LNPs.]

Response 3: We thank the reviewer for this constructive suggestion aimed at further enhancing the clarity and pedagogical value of the review. We fully agree that schematic representations of chemical structures and mechanisms of action can be highly valuable for readers. However, the primary objective of the present manuscript is to provide a focused and integrative analysis of antifungal resistance mechanisms and the role of lipid-based drug delivery systems in overcoming them. For this reason, we have deliberately prioritized original content addressing these aspects rather than reproducing general schemes that are already extensively covered in the literature.

In line with this focus, the manuscript includes an original figure (Figure 1) specifically developed by the authors, which integrates the different antifungal resistance mechanisms discussed throughout the review and highlights how lipid-based delivery systems can interfere with these processes. To the best of our knowledge, this resistance-oriented and integrative representation is not currently available in previous reviews and constitutes a key added value of the manuscript.

Regarding Section 6, we agree with the reviewer on the importance of presenting a clear comparative overview. Accordingly, the manuscript already includes a structured table that summarizes the main characteristics of the different LDDS platforms (LPs, SLNs, NLCs, and LNPs), including parameters such as stability, drug loading capacity, release profile, and principal limitations. We believe that this table provides the requested side-by-side comparison of the main characteristics of each LDDS platform, while the corresponding advantages and limitations are discussed in detail in the text.

Overall, we consider that the combination of the existing figure and comparative table adequately fulfills the purpose of improving clarity and providing a concise take-home message, while maintaining the specific scope of the review. Nevertheless, we appreciate the reviewer’s suggestion and will take it into account in future work.

 

Comments 4: [Liposomes must be consistently integrated into the general definition of LDDSs throughout the manuscript (especially in the abstract and Section 3.4), rather than being treated as a separate entity from "lipid nanoparticles."].

Response 4: We thank the reviewer for the comment. We would like to clarify that liposomes are already consistently integrated into the general definition of lipid‑based drug delivery systems (LDDSs) throughout the manuscript, including the abstract and Section 3.4.

In this review, the term LDDSs is deliberately used as the overarching category encompassing all lipid‑based nanocarriers commonly referred to in the literature as “lipid nanoparticles,” including liposomes, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and related systems. Accordingly, liposomes are not treated as a separate entity but as a core component of the LDDSs family.

To avoid ambiguity, the term lipid nanoparticles (LNPs) is reserved in this manuscript for a specific subclass of multicomponent supramolecular lipid assemblies optimized for nucleic acid delivery, as defined in Section 3.4.4.

 

Comments 5: [Polyenes: In Section 2.3, I suggest mentioning the sterol sponge model alongside the classical pore-forming mechanism, as it represents current understanding of Amphotericin B activity.]

Response 5: We thank the reviewer for this valuable suggestion. We agree that the “sterol sponge” model represents an important and more recent perspective on the mechanism of action of amphotericin B. Accordingly, we have revised the manuscript to incorporate this concept and have included the appropriate reference (Anderson et al., 2014).

 

Comments 6: [Oteseconazole: Clarify that its primary clinical breakthrough is oral administration for recurrent infections, not just topical use.]

Response 6: We thank the reviewer for this important clarification. We agree that the primary clinical relevance of oteseconazole lies in its oral administration for recurrent infections. Accordingly, the text has been revised to more clearly distinguish its route of administration and therapeutic use.

 

Comment 7: [In Section 5.1, explicitly state that drug expulsion in SLNs is driven by the transition of lipids to the stable β-polymorphic form.]

Response 7: We thank the reviewer for this insightful comment. We agree that explicitly linking lipid polymorphism to drug expulsion improves the mechanistic clarity of this section. Accordingly, the text has been revised to state that the transition from metastable polymorphic forms (α or β) to the more stable and highly ordered β-form is a key driver of drug expulsion in SLNs during storage.

 

Comments 8: [The MIC Paradox: In Section 5.6, the authors correctly note that sustained release can lead to higher MICs in vitro. I recommend suggesting time-kill kinetics assays as a more accurate method for evaluating the efficacy of LDDSs compared to endpoint MIC testing.]

Response 8: We thank the reviewer for this valuable suggestion. We agree that time-kill kinetics assays provide a more appropriate approach than endpoint MIC determinations for lipid-based drug delivery systems, as they better capture their time-dependent antifungal activity. Accordingly, this recommendation has been incorporated into the revised manuscript.

 

Comments 9: [Use fungal-specific terms like Cdr1/Mdr1 transporters instead of the mammalian 'P-glycoprotein' in the context of fungal efflux.]

Response 9: We thank the reviewer for this suggestion. The text has been revised to refer to efflux transporters and to include fungal transporters such as Cdr1p, supported by the relevant reference Moazeni et al., 2016.

 

Comments 10: [I suggest mentioning the potential of enzyme-triggered release (responsive to fungal lipases/proteases) and theranostic LDDSs to further strengthen the "Future Perspectives" section.]

Response 10: We thank the reviewer for this suggestion. The manuscript has been revised to include enzyme-triggered release strategies responsive to fungal enzymes, as well as the potential of theranostic LDDSs.

 

Comments 11: [Please correct "ketoconazol" to "ketoconazole", "terbinafineand" to "terbinafine", "polidispersity" to "polydispersity", and "stablished" to "established".]

Response 11: We thank the reviewer for these corrections. The manuscript has been revised accordingly.

 

Comments 12: [Please find my detailed, line-by-line recommendations and specific technical comments in the attached Word file.] 

Response 12: We thank the reviewer for the detailed, line‑by‑line comments provided in the attached Word file. All suggested corrections and technical recommendations have been carefully addressed and incorporated into the revised manuscript.

 

Comments on the quality of English language: [The quality of the English language is generally high; the manuscript is well-structured and uses appropriate technical terminology. However, there are minor grammatical inconsistencies, several typographical errors in drug names, and occasional issues with subject-verb agreement. A thorough proofreading is recommended to polish these minor linguistic flaws before publication.]

Response to the comment on the quality of English language: We thank the reviewer for this positive assessment and helpful suggestions. The manuscript has been carefully proofread and revised to correct typographical errors, grammatical inconsistencies, and improve overall language clarity.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript addresses a relevant and timely topic; however, several aspects could be refined to strengthen its clarity and overall impact. Greater conceptual continuity between the Introduction and the final section would be particularly valuable. The opening part of the review effectively frames the epidemiological and clinical importance of antifungal resistance, but this urgency is less visible in the concluding discussion, which shifts more strongly toward formulation and translating aspects. A more explicit return in the final section to the clinical burden and therapeutic limitations outlined at the beginning would make the manuscript more cohesive and reinforce its central message.

Additional methodological clarification would improve the scientific rigor of the review as well. As the article is written as a narrative review rather than a systematic one, it would be helpful to briefly indicate how the literature was selected and how heterogeneous findings were interpreted. This is especially important in sections where data from different formulations, pathogens, and experimental settings are discussed together. Outcomes such as MIC reduction, biofilm inhibition, improved bioavailability, intracellular accumulation, and in vivo efficacy are all relevant, but they are not directly comparable and would benefit from clearer contextualization. A short statement on the principles used to evaluate and integrate these different types of evidence would make the synthesis more transparent.

The central proposition of the manuscript, namely that lipid-based delivery systems may expand antifungal therapeutic options by overcoming pharmacokinetic and resistance-related barriers, is present throughout the text but could be stated more explicitly near the end of the Introduction. Reintroducing this same proposition in the concluding paragraph would further improve the internal coherence of the review and help frame the large amount of information presented in later sections around a clearly defined unifying idea.

Table 2 would also benefit from revision in order to improve readability and interpretation. At present, it compiles highly heterogeneous studies and endpoints in a format that is informative but somewhat difficult to compare across entries. A more standardized presentation of outcomes, or a clearer grouping of studies according to infection type, experimental model, or therapeutic aim, would make this table more accessible and analytically useful.

Overall, the manuscript would be strengthened by a clearer articulation of its central thesis, greater transparency regarding literature selection and interpretation, closer alignment between the Introduction and the concluding section, and some editorial refinement of the presentation of heterogeneous data. These revisions would improve the clarity, cohesion, and usefulness of the review for readers interested in antifungal pharmacology and lipid-based drug delivery systems.

 

Author Response

Comments 1: [The manuscript addresses a relevant and timely topic; however, several aspects could be refined to strengthen its clarity and overall impact. Greater conceptual continuity between the Introduction and the final section would be particularly valuable. The opening part of the review effectively frames the epidemiological and clinical importance of antifungal resistance, but this urgency is less visible in the concluding discussion, which shifts more strongly toward formulation and translating aspects. A more explicit return in the final section to the clinical burden and therapeutic limitations outlined at the beginning would make the manuscript more cohesive and reinforce its central message.]

Response 1: We agree with the reviewer that strengthening the conceptual continuity between the Introduction and the concluding section is important. Accordingly, we have revised the final section to explicitly reconnect LDDS‑based strategies with the clinical burden, high mortality rates, and therapeutic limitations associated with antifungal resistance, as outlined in the Introduction.

 

Comments 2: [Additional methodological clarification would improve the scientific rigor of the review as well. As the article is written as a narrative review rather than a systematic one, it would be helpful to briefly indicate how the literature was selected and how heterogeneous findings were interpreted. This is especially important in sections where data from different formulations, pathogens, and experimental settings are discussed together. Outcomes such as MIC reduction, biofilm inhibition, improved bioavailability, intracellular accumulation, and in vivo efficacy are all relevant, but they are not directly comparable and would benefit from clearer contextualization. A short statement on the principles used to evaluate and integrate these different types of evidence would make the synthesis more transparent.]

Response 2: We thank the reviewer for this important comment. As suggested, we have clarified the narrative nature of the review and included a brief methodological statement in the Introduction describing how the literature was selected and how heterogeneous findings were interpreted. Given the diversity of experimental models, formulations, fungal species, and outcome measures, evidence was integrated qualitatively rather than through direct quantitative comparison. In addition, we have specified that results were interpreted in light of the experimental context (including model system, fungal species, antifungal agent, and formulation type), with greater emphasis placed on studies providing mechanistic insights or in vivo validation. This clarification improves the transparency of the criteria used to synthesize the evidence throughout the review.

 

Comments 3: [The central proposition of the manuscript, namely that lipid-based delivery systems may expand antifungal therapeutic options by overcoming pharmacokinetic and resistance-related barriers, is present throughout the text but could be stated more explicitly near the end of the Introduction. Reintroducing this same proposition in the concluding paragraph would further improve the internal coherence of the review and help frame the large amount of information presented in later sections around a clearly defined unifying idea.]

Response 3: We thank the reviewer for this insightful comment. To strengthen the internal coherence of the manuscript, we have revised the end of the Introduction to explicitly state the central proposition of the review: that lipid‑based drug delivery systems can expand antifungal therapeutic options by overcoming pharmacokinetic and resistance‑related barriers.

 

Comments 4: [Table 2 would also benefit from revision in order to improve readability and interpretation. At present, it compiles highly heterogeneous studies and endpoints in a format that is informative but somewhat difficult to compare across entries. A more standardized presentation of outcomes, or a clearer grouping of studies according to infection type, experimental model, or therapeutic aim, would make this table more accessible and analytically useful.]

Response 4: We thank the reviewer for this valuable comment and fully agree that the heterogeneity of studies and endpoints may limit the readability and comparability of Table 2.

In its current form, the table is structured by grouping studies according to the type of lipid-based drug delivery system employed, with the aim of facilitating comparison within each formulation category.

However, in line with the reviewer’s suggestion, we have revised the table to improve its clarity and accessibility by refining and standardizing the description of the key improvements associated with each study. These changes aim to make its interpretation more straightforward while preserving the diversity of experimental approaches included in the review.