天然牡蛎壳纳米体复合型骨材料修复骨缺损

背景：研究发现，牡蛎壳等很多海洋生物外壳等形成矿物质盐的过程与人体实际情况较为接近。目的：观察天然牡蛎壳纳米体复合型骨材料修复骨缺损的效果。方法：取30只成年大耳白兔，制作双侧桡骨骨缺损模型，随机均分为两组，实验组于骨缺损处植入天然牡蛎壳纳米体复合型骨材料，对照组于骨缺损处植入医用硫酸钙可注射型植骨材料，植入后2，8，12周进行X射线检查，了解植入骨材料周围组织生长结合情况；于第12周末获得双侧桡骨，利用生物力学测试系统检测桡骨抗弯曲强度，并利用彩色图像分析仪定量分析成骨情况。结果与结论：植入后2周，两组骨材料密度较周边正常骨组织呈偏低，缺损与材料间边界清晰，未发现明显骨修复现象；植入后8周，两组骨材料均被较厚软组织全部包裹，实验组血管成分显著减少；植入后12周，两组骨材料紧密结合相邻组织，包裹骨材料的组织质地较韧，二者之间无界线，实验组桡骨表面形态已恢复至正常水平，在形态和质地结构方面与正常组织无明显区别，对照组仍存在明显投射分界影像。实验组桡骨抗弯曲强度和成骨量均显著大于对照组(P < 0.05)。表明天然牡蛎壳纳米体复合型骨材料修复骨缺损可以获得更好的桡骨抗弯曲强度，并促进新骨形成。

Natural oyster shell nanocomposite material for bone defects

BACKGROUND:Oyster shells and other shells of marine organisms can transfer into mineral salts, which is closer to the actual situation of human being. OBJECTIVE:To explore the effect of natural oyster shell nanocomposite material for bone defect repair.METHODS:Thirty adult big-eared white rabbits were randomly divided into two groups after establishment of bilateral radial bone defect models: experimental group and control group were given implantation of natural oyster shell nanocomposite material and injectable calcium sulfate bone graft, respectively. X-ray examination was done at weeks 2, 8, 12 after implantation to understand the osseointegration of bone grafts. Bilateral radial bone specimens were taken at 12 weeks to detect bending strength using biomechanical testing system and quantitatively analyze the osteogenesis using a color image analyzer.RESULTS AND CONCLUSION: At 2 weeks after implantation, the bone mineral density of bone grafts was lower in the two groups than the normal value, there was a clear boundary between the defect and graft, and no bone repair was found. At 8 weeks after implantation, the bone grafts were covered with thick soft tissues in the two groups, and the vascular component was reduced dramatically in the experimental group. At 12 weeks after implantation, the bone grafts were closely connected to the adjacent tissues in the two groups, with no boundary; the radius surface in the experimental group recovered to the normal level, and exhibited no difference from the normal tissues in aspects of morphology, texture and structure, but in the control group, there was still a clear projected boundary. The bending strength and osteogenic amount of the radius were significantly higher in the experimental group than the control group (P < 0.05). These findings indicate that the natural oyster shell nanocomposite material for bone defect repair can have a good blending strength of the radius that can promote  new bone formation.