放射性骨显像在组织工程骨修复骨缺损实验中的应用

目的观察修复兔桡骨大段骨缺损时复合了血管内皮祖细胞（EPCs）的组织工程骨的血管化及成骨情况。方法自体骨髓通过不同方法的体外培养,分别获得EPCs及经成骨诱导的骨髓间充质干细胞（MSCs）,与脱钙骨基质（DBM）构建组织工程骨修复兔桡骨大段骨缺损,通过放射性核素骨显像技术评价术后不同时期组织工程骨的血管化进程及成骨情况。结果感兴趣区（ROI）计数和摄取比值显示：术后3d,各组间差异无统计学意义,但低于正常对照。术后2、4、8周,各组均呈逐渐上升的趋势,4周和8周时达到峰值,实验组在各个时相点均高于自身对照及阴性对照组。术后12周,各组均开始下降,其中延迟相结果显示：实验组与自身对照组差异无统计学意义,但二者均高于阴性对照组。术后16周,血池相结果显示：实验组低于自身对照组,与阴性对照组无差异;延迟相结果各组差异无统计学意义。结论放射性核素骨显像对骨修复过程中的血管化及成骨具有良好的监测作用。EPCs可以促进组织工程骨的血管化,加速骨愈合。

An experimental study on radionuclide bone imaging in repairing bone defect by tissue engineering bone

Objective To observe the effects of vascularization and bone forming ability of tissue engineering bone with endothelial progenitor cells(EPCs) during rabbit radius segmental defect healing.Methods Bone marrow derived mesenchymal stem cells(MSCs) and EPCs of the same rabbits were cultured and harvested in vitro.They were seeded on decalcified bone matrix(DBM) to be tissue engineering bone,and then implanted into the radius long segmental bone defects of the donor rabbit.The vascularization of the tissue engineering bone and bone forming ability in different periods of post-operation were evaluated by radionuclide bone imaging technique.Results The counts and the uptake ratio in region of interest(ROI) showed that there was no difference between each group but it was lower than that of control group on 3 post-operation day(POD).While each group had a rising tendency at 2,4 and 8 post-operation weeks(POW),and reached the peak at 4 and 8 POW.The experimental group was higher than self-control group and the negative control group at each time point.At 12 POW,the counts and the uptake ratio in ROI of each group decreased and the delayed phase results showed that there was no difference between experimental group and self-control group;but these two groups were higher than that of the negative control group.At 16 POW,the blood-cistern phase results showed that the experimental group was lower than that of self-control group but it had no difference compared with that of negative control group;delayed phase results showed that there was no difference among all the groups.Conclusion The radionuclide bone imaging has excellent monitoring effect on the vascularization and bone forming ability in the process of bone repair.The EPCs can promote the vascularization of tissue engineering bone and can accelerate bone healing.