Surface modification of silk fibroin composite bone scaffold with polydopamine coating to enhance mineralization ability and biological activity for bone tissue engineering

Abstract Bone tissue engineering plays an important role in the treatment of bone defects. Finding suitable bone graft substitute scaffolds is still a major challenge. In this study, we combined silk fibroin‐octacalcium phosphate composite with silk fibroin by freeze‐drying technology, and the freeze‐dried scaffolds were further surface‐modified with self‐polymerization by using dopamine. The silk fibroin/octacalcium phosphate/polydopamine composite bone scaffold was successfully constructed. The composition and structure of the scaffolds were examined through Fourier infrared spectroscopy, X‐ray diffraction and scanning electron microscopy. The effects of different concentrations of polydopamine coatings on the porosity, swelling property, hydrophilicity, compressive strength, mineralization ability and biocompatibility of scaffolds were measured. The experimental results showed that the scaffolds had interconnected 3D network structure and polydopamine coating increased the compressive strength of SF scaffolds, delayed the degradation rate of scaffolds and enhanced the apatite deposition rate on the surface of scaffolds. The relative viability of cells increased with the rising of the concentration of coated polydopamine after co‐culture with MC3T3‐E1 cells. The polydopamine coating conferred the scaffolds excellent bioactivity. Therefore, silk fibroin/octacalcium phosphate/polydopamine composite scaffold may provide a new idea for bone tissue engineering.