Optimization of macroporous 3-D silk fibroin scaffolds by salt-leaching procedure in organic solvent-free conditions.

A novel all-aqueous process is described to form three-dimensional porous silk fibroin (SF) scaffolds, which not only avoided the use of organic solvents or harsh chemicals, but also can form scaffolds with various sizes and in large quantities. The scaffolds show a rough surface on the pores and the pores are highly interconnected. The porosity of the scaffolds, which varied between a large range (67.6~99.3%), can be controlled by the SF concentrations and the salt/fibroin ratio. The results of measurements indicated that this novel process can improve and enforce the transformation in SF structure from a random coil to a β-sheet. Swelling studies showed that the scaffold has excellent properties of hydrophilicity. The cell culture experiments demonstrated that the scaffolds facilitated the human osteosarcoma cells attachment and proliferation in vitro.