Calcium sulphate/bone matrix gelatin composite biomaterial for repair of bone defects

doi:10.3321/j.issn:1673-8225.2008.45.009

Abstract：BACKGROUND: Calcium sulfate (CS) is a good bone conduction material due to its good biocompatibility and degradability. However, simple CS lacks of osteoinductive capability, so it can not satisfy clinical requirements.OBJECTIVE: To verify the potential ofCS/bone matrix gelatin (BMG) composite biomaterial in the repair of segmental bone defects.DESIGN, TIME AND SETTING: An in vivo multi-dimensional observation was performed in the Laboratory Animal Center, Nanfang Hospital, Southern Medical University between December 2004 and April 2006.MATERIALS: Twenty-one healthy adult New Zealand rabbits, weighing 2.5-3.5 kg, were included. The segmental ulnar defects of 15 mm were created bilaterally. CS and BMG were self-prepared.METHODS: CS and BMG were composited at 2:1 and then implanted into 15-mm rabbit ulnar bone defect. The present study consisted of 3 groups: CS/BMG group, defects were filled with CS/BMG; CS group, defects were filled with CS; and blank control group, untreated control defects.MAIN OUTCOME MEASURES: At weeks 4, 8, and 12 post-surgery, repair of bone defect was observed by gross observation, radiographic, histomorphological and tetracycline tracing analysis.RESULTS: Surgical incisions all primarily healed. No inflammatory or foreign reaction was found around all the defects. Both CS/BMG and CS were almost completely absorbed at week 8 post-surgery. In the CS/BMG group, newly formed bone was found throughout the defects after 4 weeks; all defects were repaired with a well-organized trabecular pattern and a thit neocortex after 12 weeks. In the CS group, mass of new bone tissue formed at the periphery of the defect at week 4 post-surgery, but the development of new bone in the center of defect was latter compared with the CS/BMG group: at 12 weeks, all defects were bridged by newly formed bone tissue with little adjacent medullary bone. In the blank control group, slight new bone was found at the periphery of the defect region, and the defects were filled with fibrous tissue.CONCLUSION: CS/BMG composite is totally bioresorbable and biocompatible. The composite can repair bone defects effectively as a bone graft substitute.