Next-Generation Cancer Models for Drug Testing: Recent Advances in Immunocompetent Microphysiological Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article entitled ‘Next-generation Cancer Models for Drug Testing: Advances in Immunocompetent Microphysiological Systems’ highlights the next-generation cancer models, mainly focusing organ-on-a-chip models for immune-oncology approach. The review is well written and extensive describing 7 representative and diverse cancer models. The topic is of high significance with good impact.  The 2 figures and the table are clear and convey the messages very well. The following minor suggestions can be included to further improve the article.

1. The references cited in the entire article needs formatting as they are added after the period (except ref. 18 in line 80 which is the correct way).
2. More popular complex cell culture model including spheroid model can to be discussed more in the introduction or discussion section. Their potential for representing more TME-conditions (matrix composition, pH, nutrient availability), representing immunocompetent models is widely studied. Some of the references to add include,

• https://jitc.biomedcentral.com/articles/10.1186/s40425-019-0553-9
• Modelling the complex nature of the tumor microenvironment: 3D tumor spheroids as an evolving tool | Journal of Biomedical Science | Full Text
• https://aacrjournals.org/cancerres/article/77/13_Supplement/5767/621553/Abstract-5767-Ex-vivo-three-dimensional-tumor

Author Response

Reply: We sincerely thank the reviewer for the thoughtful and constructive comments on our manuscript entitled "Next-generation Cancer Models for Drug Testing: Advances in Immunocompetent Microphysiological Systems." We have taken in considerations all comments provided and have improved the manuscript accordingly. Point-by-point replies to each comment are provided below.

The article entitled ‘Next-generation Cancer Models for Drug Testing: Advances in Immunocompetent Microphysiological Systems’ highlights the next-generation cancer models, mainly focusing organ-on-a-chip models for immune-oncology approach. The review is well written and extensive describing 7 representative and diverse cancer models. The topic is of high significance with good impact.  The 2 figures and the table are clear and convey the messages very well. The following minor suggestions can be included to further improve the article.

1. The references cited in the entire article needs formatting as they are added after the period (except ref. 18 in line 80 which is the correct way).

RE: We appreciate the reviewer pointing out the inconsistency in reference formatting. We have now revised all citations in the text to ensure uniform formatting, placing references before the period, as exemplified by reference 18.

 

1. More popular complex cell culture model including spheroid model can to be discussed more in the introduction or discussion section. Their potential for representing more TME-conditions (matrix composition, pH, nutrient availability), representing immunocompetent models is widely studied. Some of the references to add include,

• https://jitc.biomedcentral.com/articles/10.1186/s40425-019-0553-9
• Modelling the complex nature of the tumor microenvironment: 3D tumor spheroids as an evolving tool | Journal of Biomedical Science | Full Text
• https://aacrjournals.org/cancerres/article/77/13_Supplement/5767/621553/Abstract-5767-Ex-vivo-three-dimensional-tumor

RE: We agree with the reviewer on the importance of 3D spheroid models in representing tumor microenvironment (TME) conditions and their potential in developing immunocompetent models. To address this, we have included a more detailed discussion on spheroid models in the introduction. We have also read the suggested references and added them to support the discussion.

We hope these adjustments address the reviewer’s comments satisfactorily. We thank Reviewer 1 again for their constructive feedback.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript reviews recent advances in immune-competent organoid and organ-on-a-chip (OoC) models. While the authors have made efforts to examine this topic, the manuscript requires significant improvement for journal publication. Several issues need to be addressed, and suggestions for improvement should be implemented. Consequently, I recommend either extensive revisions before publication or rejection of the manuscript.

• For Lines 15-16, the sentence should be revised to: "Advanced in vitro models can bridge this gap by offering more relevant human physiology for testing drug efficacy, safety, and absorption, distribution, metabolism, and excretion (ADME)." Minor editing for writing is required throughout the manuscript.
• In Lines 95-99, the review describes the transformative role of organ-on-a-chip (OoC) technologies in cancer immunotherapy. Since microphysiological systems have been in development for over a decade, Section 2.1 or a later discussion should include a brief overview of current industrial developments and companies commercializing MPS in 2025.
• In Section 2.2, while various tumor types are discussed in relation to OoC applications, there is no clear connection between the technical overview in Section 2.1 and these specific applications. To bridge this gap, consider adding a summary table showing microphysiological systems used in cancer immunotherapy research and development, including cell types, applications, chip materials, and technical highlights. Alternatively, adding an OoC schematic would help readers better understand these systems.
• The manuscript's broad title makes it challenging to conduct a comprehensive literature review. For example, Section 2.2.1 cited only three references (References 33, 40, 46) related to OoC applications. The authors should clarify their rationale for selecting these particular references (References 33, 40, 46; Line 182-202). Were these choices based on publication dates, or do they intentionally complement existing review papers? A summary table would be helpful, especially if additional references are to be included. Consider revising the title to: "Next-generation Cancer Models for Drug Testing: Recent Advances in Immunocompetent Microphysiological Systems".< !-- notionvc: 1ea2fdd2-a920-423d-9859-5d06e4c03587 -->
• Maintain consistent reference formatting throughout the manuscript (e.g., Reference 18, Reference 33).

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Author Response

Reply: We thank the reviewer for the detailed and constructive feedback. We appreciate the opportunity to revise the manuscript and have carefully addressed each point raised to improve the clarity, and overall quality of the review. Point-by-point replies to each comment are provided below.

This manuscript reviews recent advances in immune-competent organoid and organ-on-a-chip (OoC) models. While the authors have made efforts to examine this topic, the manuscript requires significant improvement for journal publication. Several issues need to be addressed, and suggestions for improvement should be implemented. Consequently, I recommend either extensive revisions before publication or rejection of the manuscript.

• For Lines 15-16, the sentence should be revised to: "Advanced in vitro models can bridge this gap by offering more relevant human physiology for testing drug efficacy, safety, and absorption, distribution, metabolism, and excretion (ADME)." Minor editing for writing is required throughout the manuscript.

RE: We have improved the sentence as suggested, and additionally, we have thoroughly edited the manuscript for improved grammar, clarity and style.

 

• In Lines 95-99, the review describes the transformative role of organ-on-a-chip (OoC) technologies in cancer immunotherapy. Since microphysiological systems have been in development for over a decade, Section 2.1 or a later discussion should include a brief overview of current industrial developments and companies commercializing MPS in 2025.

RE: We agree that a brief overview of current industrial developments is essential. In Section 2.1, we have added a table showing notable companies involved in the commercialization of MPS for cancer immunotherapy and drug testing (e.g., MIMETAS, TissUse, AIM Biotech), along with their key technologies.

 

• In Section 2.2, while various tumor types are discussed in relation to OoC applications, there is no clear connection between the technical overview in Section 2.1 and these specific applications. To bridge this gap, consider adding a summary table showing microphysiological systems used in cancer immunotherapy research and development, including cell types, applications, chip materials, and technical highlights. Alternatively, adding an OoC schematic would help readers better understand these systems.

RE: To bridge the gap between the general technical overview (Section 2.1) and the specific cancer applications (Section 2.2), we have uploaded a summary table including Tumor type, type of chip, methods, drug and application, perfusion duration and stability, Methods, limitations and key results as additional information. We believe this addition improves the utility of the review.

 

• The manuscript's broad title makes it challenging to conduct a comprehensive literature review. For example, Section 2.2.1 cited only three references (References 33, 40, 46) related to OoC applications. The authors should clarify their rationale for selecting these particular references (References 33, 40, 46; Line 182-202). Were these choices based on publication dates, or do they intentionally complement existing review papers? A summary table would be helpful, especially if additional references are to be included. Consider revising the title to: "Next-generation Cancer Models for Drug Testing: Recent Advances in Immunocompetent Microphysiological Systems

RE: We acknowledge that the original title may have suggested a broader scope. We have revised the title as recommended to better reflect the focus of the review. In the introduction, we also clarified our reasons for choosing the cited works. These references were chosen to represent key examples of diverse OoC platforms and tumor models. To further support transparency and comprehensiveness, we have clarified this selection strategy and uploaded a table summarizing the studies as additional information.

• Maintain consistent reference formatting throughout the manuscript (e.g., Reference 18, Reference 33).

RE: We appreciate the reviewer pointing out the inconsistency in reference formatting. We have now revised all citations in the text to ensure uniform formatting, placing references before the period, as exemplified by reference 18 and 33.

Reviewer 3 Report

Comments and Suggestions for Authors

The textual message of this review is clear and comprehensive. The authors offer a concise and timely overview of "organ-on-chip" based methods to evaluate the drug testing (focusing on several cancer types). However, I suggest a serious revision of the illustrative part of this review. The current version shown 2 schemes, which is not sufficient for a good understanidng of the processes occuring in the chips. The first scheme shows the pumps used to propulse the liquids in tchips, thereas the second shows the structure of chips and cellular assembly within them. Taken the doversity of chips and especially cells used, the authors should significantly expand the number of figures, providing additional images taken during experiments (approriately reused from the previously published literature). 

The Technological Overview section mostly focuses on pumping, however no sufficient information on the chips (the channels arrangement, etc) or imaging (microscopy) is given. This should be expanded.

 

Additional comments:

L. 78-80 "Microphysiological systems (MPS) is a terminology that describes systems that replicate complex physiologies at a small-scale, and includes OoC technologies, as well as organoids and spheroids[18]." "terminology" is obviosly not an appropriate term in this context.

L. 210-211 "Breast cancer is the most common carcinoma in women worldwide and represents a global health burden." although this might sound counterintuitive, breast cancer occurs not only in females, but in males, too. I suggest rephrasing this paragraph accordingly, currently its message is not balanced.

Author Response

Reply: We sincerely thank the reviewer for the positive feedback on the clarity and comprehensiveness of the textual content, as well as for the thoughtful suggestions to improve the illustrative and technical components of the manuscript. Point-by-point replies to each comment are provided below.

The textual message of this review is clear and comprehensive. The authors offer a concise and timely overview of "organ-on-chip" based methods to evaluate the drug testing (focusing on several cancer types). However, I suggest a serious revision of the illustrative part of this review. The current version shown 2 schemes, which is not sufficient for a good understanidng of the processes occuring in the chips. The first scheme shows the pumps used to propulse the liquids in tchips, thereas the second shows the structure of chips and cellular assembly within them. Taken the doversity of chips and especially cells used, the authors should significantly expand the number of figures, providing additional images taken during experiments (approriately reused from the previously published literature). 

RE: We appreciate the reviewer’s suggestion to enhance the illustrative elements of the review. In response, we have added two additional schematic figures illustrating various chip designs, including channel layouts, co-culture arrangements, and fluid dynamics relevant to immune-oncology studies. These additions aim to give readers a more intuitive understanding of the complexity and variability of microphysiological systems (MPS) used in cancer drug testing.

The Technological Overview section mostly focuses on pumping, however no sufficient information on the chips (the channels arrangement, etc) or imaging (microscopy) is given. This should be expanded.

RE: We agree that the initial focus on pumping was too narrow. We have expanded Section 2.1. and included a broader description of chip architecture, and techniques for imaging within chips.

Additional comments:

1. 78-80 "Microphysiological systems (MPS) is a terminology that describes systems that replicate complex physiologies at a small-scale, and includes OoC technologies, as well as organoids and spheroids[18]." "terminology" is obviosly not an appropriate term in this context.

RE: We agree with the reviewer’s observation and have revised the sentence as follows:

“Microphysiological systems (MPS) refer to in vitro models designed to replicate complex human physiologies on a small scale. This term applies to organ-on-a-chip (OoC) technologies, as well as organoids and spheroids.”

1. 210-211 "Breast cancer is the most common carcinoma in women worldwide and represents a global health burden." although this might sound counterintuitive, breast cancer occurs not only in females, but in males, too. I suggest rephrasing this paragraph accordingly, currently its message is not balanced.

RE: We have revised this sentence to be more inclusive and accurate:

“Breast cancer is the most commonly diagnosed carcinoma among women worldwide. However, it also affects men, although at a significantly lower rate. It remains a significant global health concern.“

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript has undergone signitficant improvements after the revision. Minor revisions are necessary before publishing. The following suggestions should be addressed:

1. In Line 17, remove the redundant word "testing". A complete edit of the manuscript is required to fix minor errors.
2. Between Lines 76-77, a transition sentence is needed to explain how multicellular spheroid models relate to the previous discussion. Just implementing multicellular models cannot fully solve the issues mentioned in Lines 75-76.
3. In Line 164 (Figure 1), revise the current figure title "Pumping systems." The figure demonstrates three liquid delivery methods. A rocker-based perfusion system is not strictly a pumping system in the traditional sense—rather, it is a technology that uses a rocking motion to facilitate fluid movement and perfusion in cell culture or organ-on-chip (OoC) applications.
4. In Line 195 (Table 1), the following names require revision: "3 - O system" should be "3-Organ system," "^AXLoCS" should be "^AXLung-on-Chip System," "identTx" should be "idenTx," and "HUMIMIC Chip2" should be used as the company's official product name. The Table 1 title can be revised to "Immune-competent models based on commercial OoC Platforms." The font size for the Model description column should be reduced.
5. In Line 292-298, the source citation should appear in the first sentence when introducing a research group's work, following APA and MLA guidelines. Revise citations throughout the manuscript accordingly
6. Revise the other relevant citations, for example, in Line 331, 388 and all others.
7. Maintain citation format in Line 331, and 388.
8. In Line 743, it sshould be Firgure 4. In Figures 2 (Line 419), 3 (Line 690), and 2 (Line 743), ensure the font size and typeface are consistent and readable.
9. Ensure consistent reference formatting throughout and complete any missing reference information.
10. The supplementary information was provided, but there should be a note in the content to inform readers about this additional information.

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Author Response

Dear Reviewer,

We appreciate your thorough and constructive feedback on our manuscript. Below, we have addressed each point in detail and made the necessary revisions accordingly.

1. Line 17 – Removal of Redundant Word
   The word “testing” has been removed from Line 16/17 as suggested. Also, the entire manuscript has been carefully edited to correct minor errors and enhance clarity.
2. Transition Sentence
   A transition sentence has been added between Lines 76–77 to explain how multicellular spheroid models relate to the previous discussion We acknowledge that these models alone may not fully address the mentioned limitations and have clarified this accordingly.
3. Figure 1 Title Revision
   The title of Figure 1 has been revised to: “Examples of liquid delivery methods used in organ-on-chip applications, including active and passive perfusion approaches.” We agree that the rocker-based perfusion system is not a pumping system and have updated the caption.
4. Table 1 Corrections
   We have corrected the names in Table 1 as follows:
   • “3 - O system” → “3-Organ system”
   • “AXLoCS” → “AXLung-on-Chip System”
   • “identTx” → “idenTx”
   • “Humimic Chip 2” → “HUMIMIC Chip2”.
     The title of Table 1 has been changed to: “Immune-competent Models Based on Commercial OoC Platforms.” The font size of the “Model description” column has also been reduced for a better layout.
   • Citation Placement
     The citation now appears in the first sentence when introducing the research group’s work. These adjustments have been made throughout the manuscript.
5. Figures and Font Consistency
   The label has been corrected to “Figure 4.” Figures 2, 3 and 4 have been updated to ensure consistent font size and.
6. Reference Formatting
   All references have been reviewed and edited for consistent formatting. Missing information has been added where needed.
7. Supplementary Information
   A note in the introduction has been added to inform readers about the availability of supplementary information.

We thank you once again for your supportive feedback, which has helped us improve the clarity and quality of our manuscript.

Sincerely,
Marlene Große

Reviewer 3 Report

Comments and Suggestions for Authors

The revised manuscript can be accepted

Author Response

The authors appreciate the constructive and positive appraisal of the manuscript