异黄酮介孔玻璃水泥支架材料修复兔股骨骨缺损

目的 评价异黄酮介孔玻璃水泥支架材料修复兔股骨骨缺损的效果。方法 采用不同组分的骨水泥材料,并用介孔玻璃水泥粉末吸附植物性激素大豆异黄酮(isoflavone,IS),制备成载IS的硫酸钙(calcium sulphate, CS) 骨水泥(CS/IS)、载IS的20%介孔硅酸钙镁/硫酸钙(20% mesoporous magnesium calcium silicate/calcium sulfate, 20 m-MCS/CS) 骨水泥(20 m-MCS/CS/IS)、载IS的40%介孔硅酸钙镁/硫酸钙(40 m-MCS/CS)骨水泥(40 m-MCS/CS/IS),检测不同骨水泥支架材料的体外释药性能。将60只成年雄性新西兰大白兔随机分成4组,每组15只,制作右侧股骨末端骨缺损模型后,分别植入CS、20 m-MCS/CS、40 m-MCS/CS以及40 m-MCS/CS/IS,于术后第4、8、12周各组随机处死5只兔并取材,进行micro-CT扫描,脱钙后切片并进行三色染色,普通显微镜下观察。结果 20 m-MCS/CS/IS和40 m-MCS/CS/IS骨水泥对IS的释放均为缓释,但40 m-MCS/CS/IS的释放量更多,在第25天已高达(41.0±1.8)%,因此后续实验中采用40 m-MCS/CS/IS。动物实验表明,骨水泥支架植入12周后,CS组的缺损部位仍比较明显,20 m-MCS/CS组有了一定程度的修复,40 m-MCS/CS组已基本愈合,而40 m-MCS/CS/IS组已基本完全愈合并且骨小梁已贯穿骨缺损区。三色染色结果显示40 m-MCS/CS/IS复合骨水泥有更快的降解速度,能够促进大量新生骨和成熟骨的产生,其促成骨能力也优于40 m-MCS/CS。结论 异黄酮介孔玻璃水泥能有效修复腔隙性骨缺损,有望成为新型骨缺损修复材料。
Objective To evaluate the efficacy of isoflavone (IS)-loaded mesoporous glass cement scaffold materials in repairing the rabbit femoral bone defect. Methods Various composite glass cements absorbing plant hormones (soy isoflavone) were fabricated as follows: calcium sulphate (CS), 20% mesoporous magnesium calcium silicate/calcium sulfate (20 m-MCS/CS), and 40% mesoporous magnesium calcium silicate/calcium sulfate (40 m-MCS/CS). The in vitro isoflavone release profiles of the above materials were evaluated. Sixty New Zealand rabbits were randomized into 4 groups with 15 in each group, and the bone defect models in the distal end of femur were created. Group A: implanted with CS; Group B: 20 m-MCS/CS; Group C: 40 m-MCS/CS; and Group D: IS-loaded 40 m-MCS/CS (40 m-MCS/CS/IS). The rabbits were sacrificed at 4 weeks, 8 weeks and 12 weeks postoperatively and the bone samples were scanned with micro-CT. Then histology analysis was conducted under microscope after decalcification and Masson trichrome staining. Results Controlled release profiles of isoflavone were presented in both 20 m-MCS/CS/IS and 40 m-MCS/CS/IS groups, and a higher cumulative release rate was detected in 40 m-MCS/CS/IS group, which reached (41.0±1.8)% on the 25th day; therefore 40 m-MCS/CS/IS was selected for further evaluation in vivo, and 40 m-MCS/CS, 20 m-MCS/CS and CS served as controls. Rabbits in Group A implanted with CS showed little new bone formation 12 weeks after operation; those in Group B implanted with 20 m-MCS/CS presented with better bone regeneration in the defect site; and the bone defect sites in group C grafted with 40 m-MCS/CS were almost filled with neo-bone; however, the best results were obtained in group D which was implanted with 40 m-MCS/CS/IS, with the defects fully repaired by