冻存保护剂对低温保存的组织工程骨修复骨缺损的影响

Effect of repair of bone defect by tissue engineered bone cryopreserved by cryopreservation medium

目的探讨不同方法低温保存的组织工程骨修复节段性骨缺损的差异。方法以骨髓基质干细胞(marrow stromal cells,MSCs)复合部分脱蛋白骨培养制备组织工程骨,组织工程骨分别用添加或不添加冻存保护剂的保存液于-80℃深低温冻存3个月,3个月后复温冻存的组织工程骨。选择60只新西兰白兔,制作15mm长的桡骨节段性骨缺损模型,实验根据植入不同的材料分为A、B、C和D组。A组:骨缺损区植入添加冻存剂保存的组织工程骨;B组:骨缺损区植入未添加冻存剂保存的组织工程骨;C组:骨缺损区植入未行低温保存的组织工程骨;D组:骨缺损区植入部分脱蛋白骨。术后4、8、16周取材,行X线检查、组织学观察、计算机图像分析和生物力学测定。结果术后4、8、16周各组骨缺损区均有新骨生成,成骨量随时间的推移而增加。经X线、组织学和生物力学评估,A组与C组比较未见差异(P>0.05),A组或C组分别与B组和D组比较,成骨能力依次为:A或C>B>D(P<0.001,P<0.05),其中A或C组术后16周骨缺损完全修复,骨髓腔再通,生物力学性能接近正常骨。结论选择适宜的冻存保护剂对组织工程骨的生物活性有一定的保护作用。

Objective To study the difference of repairing segmental bone defect by tissue engineered bone cryopreserved by various methods. Methods MSCs were co-cultured with partially deproteinized bone to produce tissue engineered bone. The tissue engineered bone had been cryopreserved at- 80℃ with or without cryopreserva-tion medium for 3 months and thawed 3 months later. The experimental model of 15mm radial segmental defect was produced in 60 New Zealand white rabbits, which were divided into A, B, C, D groups according to different trans-plant materials. Group A：The bone defects were repaired by tissue engineered bone stored in preservation solution with cryopreservation medium. Group B： The bone defects were repaired by tissue engineered bone stored in preser-vation solution without cryopreservation medium. Group C： The bone defects were repaired by tissue engineered bone without cryopreservation. Group D： The bone defects were repaired by partially deproteinized bone. When the samples were harvested 4,8,16 weeks postoperatively,a series of examination were carried out, including the roent-genographical,histomorphological,biomechanical and computerized graphical analysis. Results All of the defects which had been treated with implants exhibited new bone formation 4,8,16 weeks postoperatively, with the time be-ing. There was no difference between the group A and C （ P〉0.05 ） , according to radiological, histomorphological and biomechanical evaluation. The comparision study showed that ability of new bone formation in 4 groups was ranged as follows： A or C 〉 B 〉 D （ P 〈 0. 001, P 〈 0.05）. After 16 weeks, the defects in group A and C were bridged with the appearance of marrow cavities, the biomechanical property in implants approached to those of normal bone. Conclusion The choice of proper cryopreservation solution could optimize the bioactivity of tissue engi-neered bone.