Osteogenesis of collagen loaded bio-derived bone in repair of radial critical defect / 中国组织工程研究

ABSTRACT

BACKGROUND: Each matrix material alone possesses the limited ability of osteogenesis, so it is a future direction of tissue engineering that apply composite materials on the repair of bone defect by enhancing osteogenesis. OBJECTIVE: To study the osteogenesis ability of collagen loaded bio-derived bone implanted in animals. DESIGN, TIME AND SETTING: A random controlled animal experiment was completed in Tissue Engineering Laboratory of West China Center of Medical Sciences, Sichuan University between January and April in 2004. MATERIALS Sixteen New Zealand white rabbits were adopted to prepare 1.5-cm segmental defect model at the middle part of radius. Human bone was extirpated from donators, and collagen Ⅰ was the product of Sigma Company. METHODS: Rabbit models were divided into 2 groups by randomization, experimental group and control group, with 8 rabbits in each group. The extirpated bone was made into pure bio-derived bone by means of defatting, decellularization and deproteinization. Collagen loaded bio-derived bone was established by the vacuum absorption of collagen on pure bio-derived bone. Collagen loaded bio-derived bone was implanted into the defects of experimental group, while pure bio-derived bone for the control group. MAIN OUTCOME MEASURES: At 6 and 12 weeks after operation, all specimens were examined by X-ray and histological methods. RESULTS: The result analysis included all of 16 rabbit models. X-ray results showed that, osteotylus was seen in the whole defect area of experimental group at 12 weeks postoperatively, at this time osteogenesis was more obvious compared with 6 weeks, the bridge grafting of defect area was obviously visible. In the control group, osteotylus was only observed on two ends of the defects, no osteogenesis was found in the central part of defect area. Histological results showed that, new osteoid formation could be seen in internal porous zone of the experimental group at 6 weeks postoperatively, while in control group fibrous connective tissue filled internal porous zone and no new bone formed; at 12 weeks, much more woven bone-like tissues were visible and trabecular-like structure had formed in the experimental group, while osteoid tissue could be seen in bone defect area of control group. CONCLUSION: Both pure bio-derived bone and collagen bio-derived bone can enhance osteanagenesis, but collagen loaded bio-derived bone scaffold material is more effective.