This is a wonderful and complete study. The authors made a really good job in compacting a huge experimental amount of work in a very concise, clear and well written manuscript. The knowledge delivered here will be very appealing and useful to the readership of Bioengineering & Translational Medicine.

Here a few comments, questions and requests:

• Can the authors provide a more informative title? Perhaps providing the chemical nature of the glue?
• Abstract. The authors indicate that GelMA exhibited superior adhesion at cost of stiffness. Was extensibility also affected? Figure 2 shows it does. This reviewer considers that it’s relevant to mention this in the abstract too.
• In the abstract, it is not clear if only one or both glues were assessed in the swine model. Could this be clarified?
• Figure 2. It would be useful to see the representative stress vs strain curves in this Figure. Reporting toughness (the area under the curve of the stress vs strain curves) would make a lot of sense for this particular application.
• Figure 2 g. Could the authors include a brief discussion on the rheology behavior shown in both glues. mELP show particularly interesting trend, please elaborate on this.
• Figure 7. What was the control in this in vivo experiment?
Do the glues adhere to the tissues under wet conditions? Does excess of moisture has to me removed somehow? Can this procedure be explained in materials and methods?

Minor
• Figure 1. Some letters in panels (a) and (b) look small (the methacrylation conditions and the tags the polymer names). Also numbers in the x axis of panel (d) look small.

• Figure 1. It’s a little hard to distinguish the dark hues in the letters. Could the authors use more contrasting colors?

• Figure 3 c. Please add tags to the blue and red ribbons to remind that they are GelMA and mELP.

• Figure 4 (b). The tags are small compared to the other tags.

• Materials and Methods. Rheology test: a space is missing in “8mm”

• Is the caption corresponding to Figure 5 (c) OK? Are those Live/dead stainings? F-actin/DAPI stainings are not for live/dead determination.