Abstract:  Objective To fabricate a silk fibroin scaffold with biomimetic oriented microstructure using the directional crystallization technology, and to evaluate the possibility of application to the cartilage tissue engineering. Methods The silk fibroin scaffold with biomimetic oriented microstructure was made by the directional crystallization technology. The structure of scaffold was observed by the scanning electron microscope, and the pore size, porosity and mechanical properties were calculated. Adipose-derived stem cells were isolated from rabbit, and the passage 3 was seeded into the scaffold. The cell proliferation was detected by CCK8 method. The cell adhesion ability was observed by HE staining and scanning electron microscope. The cell viability was observed by LIVE/DEAD staining. Results The scanning electron microscopy showed that the parallel microtubulelike structure can be seen arranged in longitudinal section of the scaffold, which had a uniform directivity, and also the elliptical or circular pore structure in cross-section. The scaffold had a good pore interconnectivity with (112.43±12.65) µm pore diameter of the cross-section, (90.25±2.05)% porosity and (52.48±5.78) kPa the compression modulus. HE staining and scanning electron microscopy demonstrated that the cells uniformly adhered to the surface and inner pore, and which secreted lots extracellular matrix distributed in the oriented microstructure. Results of CCK8 showed that the good cell proliferation on the scaffold, and the LIVE/DEAD staining indicated that the cells were maintained good viability. Conclusion The silk fibroin scaffolds have a biomimetic oriented microstructure, and show good pore diameter, porosity, biocompatibility and biomechanical properties, which made it a suitable candidate as an alternative scaffold for cartilage tissue engineering.

Key words: tissue engineering, cartilage, silk, orientedmicrostructure, adipose-derived stem cell