Figure 5.

Fluorescence microscopy images of co-electrospun nanofibers produced under core-to-shell flow ratio of 1:4.5. (a) The shell layer; (b) The core layer; (c) The composite image of core and shell layers. The inset is an enlarged image of a selected area in (c), showing the core-shell structure of beads. The core and shell solutions were stained with fluorescein (green) and rhodamine (red), respectively. The yellow color is composited of green color and red color.