Repairing radial segmental bone defects with tissue engineered bone of silk fibroin/hydroxyapatite in rabbits

Abstract

Objective To explore the bone formation of silk fibroin/hydroxyapatite (SF/HA)co-cultured with bone marrow stromal cells (BMSCs) in rabbits. Methods The purified, culture-expanded and osteogenic BMSCs were combined with SF/HA in vitro to construct a tissue engineered bone. A segmental bone defect (15 mm in length) was created at each left radius in the rabbits which were randomized into 3 groups. The tissue engineered bone was implanted through open operation into the bone defects in Group 1. Group 2 was implanted with SF/HA scaffold alone, and Group 3 without any implant (unfilled). Bone formation and moulding were observed by X-ray at 4, 8, 12 and 16 weeks and by spiral CT reconstruction at 16 weeks. Results The rate and quality of new bone formation were significantly different among Group 1, Group 2 and Group 3 by radiography and histological scores ( P ＜ 0. 05). The segmental bone defects were completely united in Group 1, but partially united in Group 2. There was no new bone formation and the defects were only repaired by fibrous tissue in Group 3. Conclusion SF/HA with BMSCs has a good ability of repairing segmental bone defects. Key words: Silk; Hydroxyapatites; Tissue engineering; Bone defect; Rabbits