兔骨髓间充质干细胞复合生物衍生骨修复胫骨缺损

Bone marrow mesenchymal stem cells and bio-derived bone in the repair of tibial defects in rabbits

目的:探讨骨髓间充质干细胞与生物衍生骨复合修复兔胫骨的长段骨-骨膜缺损,以及修复负重骨缺损的可行性。方法:实验于2001-10/2002-08在牡丹江市第二人民医院放射科进行。①取成人尸体胫骨4具(来源于哈尔滨医科大学),切取干骺端松质骨及皮质骨2.0cm×0.5cm×0.5cm的骨块,经脱细胞、脱脂、脱蛋白及去抗原等处理后冻干,制备成生物衍生骨。②取健康成年新西兰大白兔24只,随机编号后从自体骨髓中分离出骨髓间充质干细胞,与生物衍生骨于体外复合培养,并将这24只大白兔制备成双侧胫骨中段10mm骨-骨膜缺损模型,行常规钢板螺钉固定。③随机选取其中的20只,对同一只兔将复合物植入右侧胫骨缺损处作为实验组,将单纯生物衍生骨植入左侧胫骨缺损处作为对照组;另4只兔作为空白组,双侧骨缺损不植入任何材料。然后分栏放养,观察各组兔术后一般情况。④在8,12,16,24周各时间点分别取出骨缺损修复标本,进行大体观察和骨密度测试,并进行统计学分析,以比较各组修复骨缺损的能力。结果:实验大白兔24只均进入结果分析。①各组兔术后一般情况:术后各组动物恢复及进食均正常,伤口无炎性反应,愈合良好。②各组兔骨缺损修复标本大体观察:术后8,12周实验组骨缺损部分修复,16周骨缺损完全修复,8,12,16周时实验组的骨缺损修复和骨痂生长情况明显好于对照组;24周时空白组的各缺损区均未发现有骨组织形成。③各组兔骨缺损区的骨密度测量结果:术后8,12,16周时各缺损区的骨密度实验组明显高于对照组(0.923±0.045比0.571±0.021,1.234±0.023比1.003±0.037,1.643±0.071比1.157±0.029,P<0.05)。24周时实验组与对照组比较无统计学意义(P>0.05)。空白组骨缺损未修复。结论:骨髓间充质干细胞构建的组织工程骨早期修复骨缺损能力较强,且较单纯生物衍生骨成骨量大、迅速,能够对负重骨缺损进行有效的修复。

AIM： To explore the feasibility of bone marrow mesenchymal stem cells combined with bio-derived bone in repairing loaded bone defects through observing the repair of rabbit tibial long bone-periosteum defects by rabbit bone marrow mesenchymal stem cells and bio-derived bone composite. METHODS： The experiment was carried out in the Department of Radiology of Mudanjian Second People＇s Hospital between October 2001 and August 2002. ① Forty tibias of adult corpses were provided by Harbin Medical University, the bone blocks of spongy bone and cortical bone at the metaphysis were cut with the size of 2.0 cm×0.5 cm×0.5 cm, and then they were lyophilized after decellization, defatting, deproteinization and deantigenization, and then prepared to bio-derived bone. ② The autologous marrow mesenchymal stem cells were isolated from 24 healthy adult New Zealand white rabbits after numbering at random and cultured with DBCB in vitro. The rabbit model of 10 mm bone-periosteum defects was made in the middle of bilateral tibias and fixed with plate and screw. ③ Twenty of the rabbits were selected randomly, with composite planted on the left side as the experimental group and bio-derived bone planted on the right side as the control group; the other four rabbits became the blank group without any materials planted into both sides of bone defects. Then these rabbits were fed separately and the general postoperative conditions were observed. ④ Macroscopic evaluation and bone density measurement of bone defect repairing sample and statistic analysis were performed 8, 12, 16 and 24 weeks postoperatively in order to compare the repairing ability in bone defects between the groups. RESULTS： All the 24 rabbits in the experiment entered the final analysis. ① General postoperative conditions in each group： The postoperative recovery and diet in all the groups were normal and the incisions healed well without inflammatory reactions. ②Gross observation of bone defect repair samples： In the experimental group, the bone defects were partly repaired after 8, 12 weeks and completely repaired after 16 weeks postoperatively. In macroscopic evaluations after 8, 12, and 16 weeks postoperatively, the repair of bone defects and formation of scars were superior to its self-control side statistically; bone defects in the blank group showed no formation of bone tissues after 24 weeks postoperatively. ③ The bone density measurement after 8, 12, 16 weeks postoperatively at all sites of bone defects revealed that the results of the experimental group were significantly higher than their controls （0.923 ±0.045 vs 0.571 ±0.021, 1.234±0.023 vs 1.003±0.037, 1.643±0.071 vs 1.157±0.029, P 〈 0.05）; There was insignificant difference between the experimental group and control group at 24 hours （P 〉 0.05）.No repair occurred at the site of bone defects in the blank group. CONCLUSION： The early defect repairing ability of tissue engineering bone constructed by bone marrow mesenehymal stem cells wasstrong and compared with bio-derived bone alone, the osteogenieity Was enormous and rapid so the cells could effectively repair defects of loaded bones.