不同直径的骨移植物中骨细胞转归的实验研究

The fate of donor bone cells in different diameter bone grafts: an experiment study

目的观察不同直径的骨移植物修复骨缺损过程中,供体骨内细胞转归的情况.方法近交系DA大鼠174只,其中雄性大鼠58只,作为供体;雌性大鼠116只,作为受体.将受体随机分为块状骨组、颗粒骨组和空白对照组,建立大鼠桡骨骨缺损模型,取雄性大鼠髂骨为供体骨,分别制成直径为2 mm的骨块和直径为0.3～0.5 mm的颗粒骨,植入骨缺损,分别于术后1、4 d和1、2、4、6、10周取材,采用聚合酶链反应技术观察受体骨组织中Y染色体性别决定基因(Sry)的表达情况并观察各组的组织学改变. 结果块状骨组在移植早期Sry的表达逐渐减少,至1周消失,4周后再次出现,并且随时间延长表达逐渐增多;颗粒骨组Sry的表达随时间延长逐渐减少,但各时间段均有Sry的表达.在同一时间点,颗粒骨较块状骨有更多的骨细胞存活,其成骨效果优于块状骨. 结论不同直径的骨移植物修复骨缺损时均有供体骨细胞参与,但颗粒骨内有更多的骨细胞存活,这些骨细胞参与骨缺损修复的各个阶段,并能加速骨缺损的修复,为临床上修复骨缺损和脊柱融合提供了新的有效的方法.

Objective To investigate the fate of donor bone cells in bone grafts of different diameters during repairing bone defects. Methods One hundred sixteen female syngeneic inbred DA rats were established as radial defect model of 3 kinds： structural bone grafting group （n = 56） , morselized bone grafting group （n =56）, and blank group （without bone grafting, n =4）, to be used as receptors The ilia of 58 male inbred DA rats, as donors, were harvested and made into structural bone grafts 2 mm in diameter and morselized bone grafts 0. 3 - 0. 5 mm in diameter to be transplanted into the radial defects of the female receptors. One and four days, and 1,2, 4, 6, and 8 weeks after transplantation DNA was extracted from the grafted bones and polymerase chain reaction （PCR） specific for the sex-determining region of Y-chromosome （Sry） was performed to observe the presence and relative amount of Y-chromosome originating from the bone grafts, expression of the sex-determining gene Sly in the receptors＇ bones and the histology of the receptors＇ bones. Results In structural bone grafting group, the amounts of Sry-specific bands decreased in the early time and disappeared 1 week after transplantation, and re-appeared 4 weeks after transplantation with the amount increasing with the lapse of time. In morselized bone grafting group, Sry-specific bands were detected all the time but their amounts decreased with the lapse of time. At each time point, morselized bone graft provided more living osteocytes with better effect of osteogenesis in comparison with the structural bone graft. Conclusion Bone grafts of different diameters provide donor cells in repairing bone defects. Having more surviving osteocytes, morselized bone grafts may accelerate the healing pf bone defects, thus providing a new and effective method to repair bone defects and spinal fusion clinically.