^(153)Sm-Annexin V凋亡显像的实验研究

Experimental studies on apoptosis imaging of ^(153)Sm-Annexin V

目的:探讨放射性核素153Sm标记Annexin V凋亡显像的可行性。方法:采用环二乙三胺五醋酸(DTPA)法进行153Sm-Annexin V制备,并进行物理、化学及生物学检测。应用153Sm-Annexin V进行体外细胞培养及荷瘤小鼠动物凋亡显像实验。结果:经环DTPA法制备的153Sm-Annexin V无色透明,pH为7.4,比活度100μg/10 mCi/2 mL;放化纯RCP>90%,标记率为88.6%;无菌,无热原,LD50>333μg/kg体质量,血浆半衰期13 min;体外细胞培养及荷瘤小鼠动物凋亡显像实验均阳性。结论:153Sm-Annex in V作为放射性核素凋亡显像剂,标记率高,半衰期相对较长,利于进行连续追踪监测、捕捉细胞凋亡活动的高峰期,进而确立最佳凋亡显像时间窗,有广泛的临床应用前景。

Objective： This work aimed to investigate the feasibility of apoptosis imaging ofAnnexin V labeled with the radionuclide ^153Sm. Methods： ^153Sm-Annexin V was prepared by using the cyclic diethylene triamine pentaacetic acid （DTPA） method, after which physical, chemical, and biological assays of the protein were conducted. Apoptosis imaging experiment both for in vitro cell cul- ture and for tumor-bearing mice was performed using l＇3Sm-Annexin V. Results： The features of 153Sm-Annexin V prepared via the cy- clic DTPA method are as follows： colorless and transparent, pH 7.4, radioactivity of 100 μg/10 mCi/2 mL, radiochemical purity of over 90%, and 88.6% radiolabeling rate. Annexin V is sterile, pyrogen-free, and presents an LD50 of 333 μg/kg body weight and plasma half-life of 13 min. Positive apoptosis images were obtained from both cultured cells and tumor-bearing mice. Conclusion： ^153Sm-An- nexin V, as a radionuclide-labeled apoptosis imaging agent, exhibits a high labeling rate and relatively long half-life. The agent can efficiently facilitate continuous tracking and capturing of apoptotic peak activity, thus establishing an optimal apoptosis imaging window period. These advantages indicate that the proposed imaging method has great potential in many clinical applications.