Silk fibroin‐chondroitin sulfate‐alginate porous scaffolds: Structural properties and in vitro studies

The development of porous biodegradable scaffolds is of great interest in tissue engineering. In this regard, exploration of novel biocompatible materials is needed. Silk fibroin‐chondroitin sulfate‐sodium alginate (SF‐CHS‐SA) porous hybrid scaffolds were successfully prepared via lyophilization method and crosslinked by 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide‐ethanol treatment. According to the scanning electron microscopy studies, mean pore diameters of the scaffolds were in the range of 60–187 μm. The porosity percentage of the scaffold with SF‐CHS‐SA ratio of 70 : 15 : 15 (w/w/w %) was 92.4 ± 3%. Attenuated total reflectance Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry results confirmed the transition from amorphous random coil to crystalline β‐sheet in treated SF‐CHS‐SA scaffold. Compressive modulus was significantly improved in hybrid scaffold with SF‐CHS‐SA ratio of 70 : 15 : 15 (3.35 ± 0.15 MPa). Cytotoxicity assay showed that the scaffolds have no toxic effects on chondrocytes. Attachment of chondrocytes was much more improved within the SF‐CHS‐SA hybrid scaffold. Real‐time polymerase chain reaction analyses showed a significant increase in gene expression of collagen type II, aggrecan, and SOX9 and decrease in gene expression of collagen type I for SF‐CHS‐SA compared with SF scaffold. This novel hybrid scaffold can be a good candidate to be utilized as an efficient scaffold for cartilage tissue engineering. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41048.