1. Why was collagen blended to PCL? The authors should explain the reason and the implication for collagen.
2. Describe the detailed condition, including the diameters of core and shell nozzle diameters …show more content…
Describe the observation conditions of SEM, including the coating conditions and the applied voltage.
6. Fig. 1D. How did the authors identify the core-shell structure by SEM?
In the reviewer’s consideration, it is very difficult to detect the significance difference of the contrast of the secondary electron scattering between core material and shell material which are identical except 0.1% DMOG.
7. Fig.1D. The diameter of an observed fiber was approximately 1 micron, although the averaged size was 391 nm. In addition, the background of this image was film-like, which looks the beaded region in the electrospinning. The authors should show the distribution of the fiber diameter and provide the representative picture.
8. How is the completeness of the core-shell structure? Is there any fibers which are composed of core solution solely, shell solution solely, or mixture of core and shell solutions? The authors should show the experimental evidence of the core-shell structures.
9. The reviewer considers that collagen embedded in the fibers might be eluted in the medium because it is denatured in HFIP into gelatin form. The authors should show the morphological stability, including fiber diameters, after immersed in the