^(125)I标记CD90单克隆抗体靶向结合间充质干细胞的实验研究  

Experimental study on^(125)I labeled CD90 monoclonal antibody for targetedly binding mesenchymal stem cells

作　　者：吴江 张晓懿[2] 孙传金 吉蘅山 朱虹 Wu Jiang;Zhang Xiaoyi;Sun Chuanjin;Ji Hengshan;Zhu Hong(Department of Nuclear Medicine,General Hospital of Eastern Theater Command,Nanjing 210002,China;Department of Nuclear Medicine,Changshu No.2 People's Hospital of Jiangsu Province,Changshu 215500,China)

机构地区：[1]东部战区总医院核医学科,南京210002 [2]江苏省常熟市第二人民医院核医学科,215500

出　　处：《国际放射医学核医学杂志》2021年第2期88-93,共6页International Journal of Radiation Medicine and Nuclear Medicine

基　　金：江苏省自然科学基金(BK20160610);江苏省博士后科研基金计划项目(1601090C)。

摘　　要：目的制备^(125)I标记的CD90单克隆抗体(mAb),探讨其示踪间充质干细胞(MSCs)的可能性。方法采用氯胺T法对CD90 mAb进行^(125)I标记,测定标记率。(1)体外实验:检测MSCs和^(125)I-CD90 mAb孵育后上清液和沉淀的放射性计数,分别计算6个不同时间点的细胞结合率。(2)体内实验:构建荷瘤BALB/c裸鼠,采用完全随机法分为4组(每组3只),a组经腹腔注射MSCs,b组经腹腔注射生理盐水,c组经瘤内注射MSCs,d组经瘤内注射生理盐水。每只荷瘤裸鼠尾静脉注射^(125)I-CD90 mAb(3.7 MBq/0.2 mL)后行Micro-SPECT/CT显像,测定并计算在4个不同时间点肿瘤及主要器官和组织的放射性摄取值[每克组织百分注射剂量率(%ID/g)]。2组均数之间的比较采用独立样本t检验。结果^(125)I-CD90 mAb标记率为54.4%,放射化学纯度为98.79%。(1)在10 min、30 min、1 h、2 h、6 h、8 h时,^(125)I-CD90 mAb与MSCs的结合率分别为0.86%、1.73%、1.88%、5.67%、12.20%、10.69%,6 h时最高。(2)荷瘤裸鼠的肿瘤长至150~200 mm3时用于实验。在注射后6 h、1 d、2 d、3 d时,Micro-SPECT/CT显示^(125)I-CD90 mAb在荷瘤裸鼠的肿瘤及主要器官和组织中有着不同程度的分布,其中a组肿瘤组织的放射性摄取值分别为(3.66±1.69)、(2.35±1.30)、(1.36±0.95)、(1.33±0.84)%ID/g,均高于b组的(2.93±1.74)、(1.92±1.15)、(1.12±0.78)、(1.03±0.72)%ID/g,但差异均无统计学意义(t=0.35~0.52,均P>0.05);c组肿瘤组织的放射性摄取值分别为(5.75±1.30)、(3.75±0.77)、(2.70±0.44)、(1.88±0.48)%ID/g,均高于d组的(3.17±0.75)、(2.03±0.54)、(1.44±0.39)、(1.38±0.27)%ID/g,且差异均有统计学意义(t=1.59~3.70,均P<0.05)。结论成功制备的^(125)I-CD90 mAb具有良好的与MSCs结合的能力,有潜力作为核素探针示踪MSCs。Objective To prepare ^(125)I-CD90 monoclonal antibody(mAb)and evaluate its potential as a molecular imaging agent to trace mesenchymal stem cells(MSCs).Methods ^(125)I-CD90 mAb was prepared by chloramine T method,and labeling rate was tested.(1)In in vitro experiment,the radioactive count of the supernatant and precipitate was measured after incubating ^(125)I-CD90 mAb with MSCs.Binding fraction was calculated at six time points.(2)In in vivo experiment,tumor-bearing BALB/c mice were constructed and divided into four groups(a,b,c and d)by completely random design.MSCs and normal saline were administered by intraperitoneal injection in groups a and b,respectively.MSCs and normal saline were given by intratumoral injection in groups c and d,respectively.^(125)I-CD90 mAb(3.7 MBq/0.2 mL)was injected via caudal vein in each mouse,and Micro-SPECT/CT analysis was performed.The radioactive uptake values(percentage activity of injection dose per gram of tissue(%ID/g))in tumor and main organs was calculated at four different time points.The difference between two groups was analyzed by two independent sample t test.Results The labeling rate and radiochemical purity of ^(125)I-CD90 mAb were 54.4%and 98.79%,respectively.(1)After incubation for 10 min,30 min,1 h,2 h,6 h and 8 h,the binding ratios of ^(125)I-CD90 mAb in MSCs were 0.86%,1.73%,1.88%,5.67%,12.20%and 10.69%,respectively.The highest binding ratio was detected at 6 h of incubation.(2)Tumors of tumor-bearing mice(150-200 mm3)were used.Micro-SPECT/CT images showed varying degrees of ^(125)I-CD90 mAb distribution in the tumor and main organs of MSCs tumor-bearing mice after 6 h,1 d,2 d and 3 d of incubation.The radioactive uptake values in the tumor were(3.66±1.69),(2.35±1.30),(1.36±0.95)and(1.33±0.84)%ID/g in group a,which were higher than those((2.93±1.74),(1.92±1.15),(1.12±0.78)and(1.03±0.72)%ID/g)in group b,at 6 h,1 d,2 d and 3 d,respectively,but the differences were not statistically significant(t=0.35-0.52,all P>0.05).The radioactive uptake values in the

关 键 词：间质干细胞 抗体 单克隆 Thy-1抗原 碘放射性同位素 体层摄影术 发射型计算机 单光子 

分 类 号：R730.5[医药卫生—肿瘤]