Application of silk fibroin bio-material combined with bone marrow mesechymal stem cells in the construction of tissue engineered bone for repairing of segmental bone defect

Objective To investigate the possibility of adopting the silk fibroin biomaterial as the scaf-fold for bone marrow mesechymal stem cells(BMSCs) in the repair of rabbit radial defects. Methods BMSCs were isolated and co-cultured with the silk fibroin biomaterial in vitro. The growth condition of these cells on the scaffold was observed under electronic microscope. Bone defect models were made by removing 15 mm length of midshaft radial bone in 24 New Zealand rabbits. Animals were randomly devided into the experimental group in which the BMSCs seeded silk fibroin scaffold were transplanted, control group in which simple silk fibroin bioma-terial scaffold was adopted and blank group in which rabbits were left untreated. The repair of the defects was observed at 2, 4, 8, 12 weeks after operation, respectively. Results The rabbits BMSCs grew well on the material and the animals treated with grafts exhibited new bone formation. Result from experimental group was apparently superior to that of the control group at 2, 4, 8, 12 weeks after operation. No formation of new bone was found after operation in the blank group. Conclusion The proposed method of combining the BMSCs with silk fibroin bio-material to repair the rabbit radial defects is feasible, and the silk fibroin biomaterial can be applied in the bone tissue engineering as the material of frame. Key words: Silk fibroin biomaterial ;  Mesenchymal stem cells ;  Bone tissue engineering ;