Radially porous nonmulberry silk fibroin nanofiber scaffolds for bone repair

An ideal bone tissue engineering scaffold is expected to possess anisotropic architectures to facilitate cell adhesion and migration and thereby to induce bone tissue regeneration. However, it is still challenging to create a scaffold with the desired nanostructure and anisotropic microstructure that can promote bone repair. Herein, we developed a facile strategy to create a pure nonmulberry Tussah silk fibroin (TSF) nanofiber scaffold with a radially ordered microstructure by physical shearing and directional ice crystallization. Physical shearing disassembles natural silk into nanofibers with diameters ranging from 50 to 500 nm. TSF nanofibers in aqueous solution are intertwined into a 3D porous scaffold with radially aligned channels via radial ice templating. The width of the radiating structure in the scaffold increased with distance from the center, and the TSF nanofiber concentration decreased. These scaffolds supported cell adhesion, migration and proliferation in vitro and accelerated bone regeneration in vivo . The biomimetic structures and tunable radial structures support the potential application of radial TSF nanofiber scaffolds in bone tissue engineering.