放射性核素骨显像动态检测组织工程化骨血管化的价值

Values of radionuclide bone imaging to dynamically monitor revascularization of tissue-engineered bone graft in repairing bone defect of rabbits

[目的]放射性核素骨显像动态检测评价组织工程化骨血管化与骨代谢的价值。[方法]取大白兔24只,抽取骨髓,行骨髓间充质干细胞分离、培养与骨向诱导。双侧股骨髁制作0.6 cm×1.2 cm的骨缺损,将诱导后的骨髓间充质干细胞与珊瑚羟基磷灰石复合植入左侧骨缺损处为实验组,右侧单纯植入珊瑚羟基磷灰石为对照组。术后4、8、12周分别行静态放射性核素骨显像检测,用ROI计数计算不同时间点的ROI平均计数。[结果]结果术后4、8、12周实验组ROI计数(单位像素)均较对照组有显著性增高。实验组ROI计数随时间的延长,呈明显的上升趋势,术后8周开始增长放缓;对照组ROI计数术后8周增长缓慢,8周后开始增长加快,两组均在12周达到峰值。[结论]骨髓间充质干细胞诱导后与珊瑚羟基磷灰石复合可有效的修复股骨髁松质骨缺损。放射性核素骨显像可动态检测组织工程化骨血管化及骨代谢变化。

[ Objective ] To dynamically monitor revascularization and metabolism of tissue-engineered bone graft in repairing bone defects by radionuclide bone imaging. [ Method] Twenty-four healthy New Zealand rabbits were studied. Mesenchymal stem cells （MSCs） were separated and cultured from bone marrow. Cancellous bone defects（0.6 cm × 1.2 cm） were created on bilateral femoral condyles in rabbits. The compound of coral hydroxyapatite ceramic （CHA） and defects were treated with the induced osteoblasts inplanted into the left defects （experimental group）. While CHA alone was used for the right （control group）. The counts of regions of interest（ROI） was evaluated by radionuclide bone imaging at 4,8 and 12 weeks postoperatively. [ Result] ROI in the experimental group was significantly higher than that of control group at 4,8 and 12 weeks postoperatively. ROI in either group had a tendency to increase with time. Eight weeks postoperatively, ROI in experimental group tended to increase at a lower speed, while ROI in control group had a tendency to increase at a higher speed. ROI in either group reached a peak at 12 weeks postoperatively. [ Conclusion ] The tissue-engineered bone graft is an effective method for repairing cancellous bone defects. Radionuelide bone imaging can dynamically monitor the changes of revaseularization and metabolism of tissue-engineered bone graft.