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In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] The tissue engineering is a promising method for cartilage regeneration studies. The rough in vivo initial repair environment of articular cartilage is a challenge for the development of cartilage tissue engineering. Hereon, in this study, a silk fibroin/collagen type II scaffold was designed. The optimal mechanical environment for chondrocyte/scaffold complex in vitro maturation culture was determined and in vitro cultured mature artificial cartilage was evaluated for in vivo defect repair. Our research shows that the silk fibroin/collagen type II scaffold has good performance and can meet the special requirements of cartilage repair. 10 % compressive strain is the optimal compressive loading in vitro. Under optimal compression loading in vitro , chondrocytes can proliferate and grow rapidly on the scaffold to achieve better "maturation". The in vitro cultured chondrocyte/scaffold complex effectively improves the cartilage repair effect after implantation. The compressive elastic modulus of the new tissue reached 0.682 ± 0.010 MPa after 12 weeks of repair (0.714 ± 0.011 MPa for the surrounding host cartilage). Therefore, this study not only enhance the effect of cartilage repair but also provides a promising strategy for mechanical stimulation to promote functional in situ regeneration of articular cartilage. [ABSTRACT FROM AUTHOR]