Collagen I Microfiber Promotes Brain Capillary Network Formation in Three–Dimensional Blood–Brain Barrier Microphysiological Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 The group of authors investigated the advantages of using collagen I microfibers in addition to fibrin gel to fabricate BBB-NET. They showed that collagen I microfibers accelerated the formation and maturation of the capillary network by promoting astrocyte survival considering a role for integrins. The manuscript can be considered original as it fills some gaps in microphysiological systems. The manuscript can be further considered with some minor improvements as follows:

1-      Please name the most important markers required to control the quality of collagen I microfibers in the conclusion section  

2-      The number of references can be enriched by improving the discussion section.

 

3-      Please revise the engagement in the writing style, English, and Grammar.

Comments on the Quality of English Language

Please revise the engagement in the writing style, English, and Grammar.

Author Response

Please see the attachment file.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript by Nakayama-Kitamura and coworkers described a novel method to generate a 3D cell culture that mimic the blood-brain barrier (BBB) which will provide better understanding of pharmacokinetics/pharmacodynamics (PKPD), toxicokinetics/toxicodynamics (TKTD), toxicity, safety, and efficacy in the central nervous system. Previously, the 2D microphysiological systems (MPS) which were used widely to study the BBB. Sato group also developed 3D cell culture system in hydrogel to better study the BBB-MPS. In this manuscript, the authors reported the effects of collagen I microfibers (CMFs), endothelial cell, astrocytes and their interaction which increases capillary network formation. The authors also demonstrated the collagen I fragments improve the survival of Astrocytes by interacting with Integrin b1. In this paper, the authors successfully developed an in-vitro condition that produces a stable BBB-NET. Overall, the conclusions are well supported by the data. I recommend this manuscript to be published in Biomedicines after the authors addressed the following concerns.

1.       More introduction is needed to discuss the reason why the authors are looking for certain changes, such as CD31, CD146, etc. A detailed explanation of why those changes lead to favorable outcomes will improve the readership of the manuscript.

2.       A better explanation is needed to demonstrate how the results generated by confocal microscope are representative to the overall 3D cell culture without human preference.

Author Response

Please see the attachment file.

Author Response File: Author Response.docx