MRI示踪超顺磁性氧化铁标记兔脂肪干细胞治疗关节软骨缺损的研究  

MRI Tranking of Superparamagnetic Iron Oxide-Labeled Rabbit Adipose-Derived Stem Cells for Treatment of Carticular Carilage Defect

作　　者：刘锴[1] 李春波[2] 陈增淦[2] 曾蒙苏[1] 傅彩霞 陈财忠[1] 

机构地区：[1]复旦大学附属中山医院放射科,深圳518057 [2]复旦大学附属中山医院骨科,上海200032 [3]西门子(深圳)磁共振有限公司,深圳518057

出　　处：《中国临床医学》2015年第5期589-595,共7页Chinese Journal of Clinical Medicine

摘　　要：目的:利用磁共振成像技术动态监测超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)标记的兔脂肪干细胞(adipose-derived stemcells,ADSCs)在兔体内的变化及其对兔膝关节软骨缺损修复的进程。方法:用不同浓度(0、12.5、25、50、100μg/mL)的超顺SPIO标记ADSCs。采用普鲁士蓝染色法测定细胞的标记情况,并计算细胞标记率。用细胞计数试剂盒(CCK-8)测定不同浓度的SPIO对细胞活性的影响。将不同浓度SPIO标记的不同数量的ADSCs快速均匀地重悬于盛有1%琼脂糖的冷冻管中进行体外MRI成像,测量T2*图像信号强度。将50μg/mL的SPIO标记的ADSCs接种至聚乳酸-羟基乙酸共聚酶[Poly(lactic-co-glycolic acid),PLGA]支架材料后,回植入兔(n=5)膝关节软骨直径为3 mm的软骨缺损处,分别于术后1、4、8和12周进行MRI T2*序列动态扫描,监测干细胞在体内的变化及关节软骨的修复情况。结果:原代培养的ADSCs呈成纤维细胞样外观,培养7 d后细胞呈聚集样生长。普鲁士蓝染色见细胞质内有明显的蓝色致密颗粒,随着SPIO浓度的升高,蓝色致密颗粒增多;当SPIO的浓度≥50μg/mL时,细胞的标记率可达100%。CCK-8检测显示,SPIO的浓度越高,细胞的活性越低,当SPIO的浓度大于50μg/mL时,细胞的活性明显降低(P<0.05)。体内MRI显示,术后1周和4周可见颗粒状低信号区域,信号强度明显低于对照组。术后8周,颗粒状低信号范围逐渐缩小,信号强度接近周围组织,说明SPIO标记的ADSCs在动物体内存活良好,并正常分裂增殖,形成正常关节软骨结构。结论:MRI联合SPIO可以动态监测细胞在体内的分布、生长和转归,有望作为一种动态监测组织工程修复关节软骨缺损效果的方法。Objective：To detect dynamically in vivo superparamagnetic iron oxide-labeled rabbit adipose-derived stem cells（ADSCs）for treatment of carticular cartilage defect with MRI tracking technique.Methods：Rabbit ADSCs were firstly labeled with different concentrations of SPIO（0μg/mL,12.5μg/mL,25μg/mL,50μg/mL,and 100μg/mL）.The labeled ADSCs were stained with Prussian blue and the labeling rates were calculated.The activities of different concentration SPIO-labeled ADSCs were determined by CCK-8.Different amounts of different concentration SPIO-labeled ADSCs were dissolved homogeneously in cryovial with 1% agarose and T2＊-weighted MRI was used to evaluate their signal intensity in vitro.Then50μg/mL SPIO-labeled ADSCs and unlabeled ADSCs were seeded in PLGA [Poly（lactic-co-glycolic acid）]scaffold,respectively.Following that,the cells-PLGA scaffold compounds were implanted in the rabbit（n=5）articular cartilage defect with average diameter 3 mm.At 1,4,8,and 12 weeks post-operatively,the change of implanted-ADSCs and the repain of articular cartilage defect were dynamically detected by T2＊-weighted MRI.Results：Primarily cultured rabbit ADSCs presented fibroblast-like appearance,and ADSCs proliferated with aggregations after 7 days.Prussian blue staining showed amount of blue dense granules in cytoplasm.With the increasing of SPIO concentration,the count and region of blue dense granules increased.When SPIO concentration reached 50μg/mL,the labeling rate of ADSCs reached 100%.The measure of CCK-8showed that the activities of ADSCs decreased with the increasing of SPIO concentration.When the SPIO concentration was greater than50μg/mL,the activities of ADSCs were obvious low（P〈0.05）.In vivo,MRI showed postoperative 1 week and4 weeks visible granules with low signal area,and the signal strength was significantly lower than the control group.Until 8weeks post-surgery,granules with low signal area gradually narrowed and signal strength was similar to the control group.SPIO-labeled ADSCs lived

关 键 词：磁共振 脂肪干细胞 超顺磁性氧化铁 细胞示踪 

分 类 号：R684[医药卫生—骨科学]