ABSTRACT
objective: To develop injectable tissue engineered bone through injection of osteoblasts/alginate composite in rabbits. Methods: Bone marrow cells isolated from iliac bone of New Zealand rabbits were cultured and induced to differentiate into osteoblasts.The osteoblasts were mixed with 25 g/L sodium alginate solution to generate osteoblasts/alginate composite with final cellular density of 5?10 6/ml. 0.17 g of sterilized CaSO 4 powder was then added to 2 ml osteoblasts/alginate. The mixture was injected into the dorsal subcutaneous tissue at left side of 6 New Zealand rabbits. The alginate composite without osteoblasts was injected into the right side as the control. 4 and 8 weeks after implantation, the bone formation was evaluated by means of gross, X ray and histological observation. Results: 4 weeks after implantation, cartilage formation was observed and 8 weeks after implantation,new mature bone was observed in the osteoblasts/alginate composites. No new bone formation was observed in all of the control specimens. Conclusion: Calcium alginate can be used as a carrier in injectable bone tissue engineering, and new bone can be created through injection of osteoblasts/alginate composites in immune animals.