海螵蛸/外消旋聚乳酸复合人工骨在动物体内的降解及相容性

Degradation and compatibility of cuttlebone/racemic polylactic acid composite artificial bone in animals

背景:为改善海螵蛸作为骨修复材料时降解不完全问题,前期研究制备了海螵蛸/外消旋聚乳酸复合人工骨材料。目的:观察海螵蛸/外消旋聚乳酸复合人工骨在动物体内的降解及生物相容性。方法:将30只新西兰大白兔随机分为4组,制作右侧桡骨缺损区,实验组于骨缺损处置入海螵蛸/外消旋聚乳酸复合人工骨块,并在靠上方外侧肌和直肌肌囊内置入海螵蛸/外消旋聚乳酸复合人工骨片;对照1组于骨缺损处置入海螵蛸块,并在靠上方外侧肌和直肌肌囊内置入海螵蛸片;对照2组于骨缺损处置入外消旋聚乳酸块,并在靠上方外侧肌和直肌肌囊内置入外消旋聚乳酸片;空白对照组不置入任何材料。术后2,4,8周进行X射线与组织学检查。结果与结论:(1)骨缺损置入实验:实验组术后4,8周的骨密度高于对照组1组、对照2组、空白对照组(P<0.05),术后不同时间点的骨矿化沉积率高于对照1组、对照2组、空白对照组(P<0.05)。术后8周时,实验组骨组织由两端周围向材料中央方向生长,形成多处骨岛状结构,材料残存较少,骨髓腔与材料呈相交通状;对照1组残存材料较多,骨髓腔与材料未交通;对照2组残存材料较多,骨髓腔与材料未交通。(2)肌囊埋置实验:3种材料置入后2周材料周围炎症细胞较多,术后4周减轻,术后8周基本消失,材料部分降解。结果表明海螵蛸/外消旋聚乳酸复合人工骨具有良好的生物相容性及降解性。

BACKGROUND： Cuttlebone/racemic polylactic acid composite artificial bone has been prepared in the previous studies to improve the incomplete degradation of cuttlebone. OBJECTIVE： To observe the degradation and biocompatibility of cuttlebone/racemic polylactic acid composite artificial bone in animals. METHODS： Thirty healthy New Zealand white rabbits were randomly divided into four groups. Models of right radial defects were prepared in rabbits, and model rabbits were subjected to implantation of cuttlebone/racemic polylactic acid composite artificial bone into the defects and muscular sac between the radial lateralis muscle and rectus（experimental group）, implantation of cuttlebone into the defects and muscular sac between the radial lateralis muscle and rectus（control group 1）, implantation of racemic polylactic acid into the defects and muscular sac between the radial lateralis muscle and rectus（control group 2）, or no treatment（blank control group）, respectively. At 2, 4, 8 weeks after operation, X-ray and histological examinations were performed in the four groups. RESULTS AND CONCLUSION：（1） Compared with the other three groups, the bone mineral density of the experimental group was significantly higher at 4 and 8 weeks after material implantation into the defects（P〈0.05）, and moreover, the bone mineral apposition rate of the experimental group was significantly higher at different time after operation（P〈0.05）. At 8 weeks after operation, the bone tissues in the experimental group grew from the both ends to the center to form multiple bone island-like structures, with less residual materials, and the marrow cavity and implanting material were in a traffic manner; in the control group 1, there were many residual materials, and no intercommunication was found between the marrow cavity and implant material.（2） At 2 weeks after material implantation into the muscle capsule, there were more inflammatory cells, but the inflammation relieved at 4 weeks and disappeared basically at 8 weeks, and the material was degraded partially. These findings indicate that the cuttlebone/racemic polylactic acid composite artificial bone is a kind of good bone substitute material that has good biocompatibility and degradability.