Silk scaffold fabrication. Silk fibroin is extracted from silkworm cocoons into an aqueous solution. Aqueous-based spherical-pore scaffolds (Aq-250 and Aq-500) are
produced by the salt-leaching method, where small (250–500 lm) or large (500–1000 lm) NaCl particles are used as the porogen. Aqueous-based lamellar scaffolds (Aq-Lam)
are produced by lyophilizing the frozen aqueous silk solution cast in a silicon tube. HFIP-derived porous scaffolds (HFIP-400) are developed by dissolving the lyophilized
aqueous silk solution in HFIP solvent, to which NaCl particles (400–600 lm) are added to form the porous structure. The NaCl particles used in the salt-leaching method are
further dissolved in water. Bold text represents the step where b-sheet formation occurs