^125I标记碳纳米材料石墨烯及其稳定性研究

Investigation of Labeling Graphene with ^125I and the Stability of the Labeling Product

目的研究放射性核素^125I标记聚乙二醇修饰的碳纳米石墨烯材料（Graphene-PEG 18kDa）的可行性及其标记产物的稳定性。方法采用氯氨一T法标记石墨烯材料（GP-18）．Millipore超滤离心管对产品进行分离纯化，并测定^125I-GP-18的标记率；纸层析法测定放射化学纯度；将^125I-GP-J8，按1：20的比例分别加入到生理盐水、血清中，置于37℃、4℃、室温条件下，测定放置2h、4h、24h、48h后标记物的放化纯度以评价其体外稳定性。结果^125I标记GP．18的标记率为（56．93±2．85）％，^125I-GP-18的放射化学纯度（97．93±0．70）％．放射性比活度为52．81MBq／mg。4aC生理盐水中放置48h的放射化学纯度仍可达（93．48±1．20）％，但在37屯血清中放置2h放化纯降为（71．94士5．47）％（P〈0．01）。结论可用^125I标记碳纳米材料石墨烯，所得产物放射化学纯度及放射性比活度高，但在37℃血清中稳定性欠佳，其结构有待进一步改进。

Objective To explore whether graphenes functionalized with 18kDa polyethylene glycol（PEG） could be labeled with ^125I and the stability of the labeling product.Methods Labeling GP-18 with ^125I by chloramine T method,then puri ified with Millipore ultrafiltration centrifuge tube.The radiochemical purity of ^125I-GP-18 were tested with paper chromatography.The stability of the labeling product which detected in NS and human serum were analyzed. Results The labeled rate was （56.93 ± 2.85）%,and the radiochemical purity was （97.93 ± 0.70）%. The radio-activity of ^125I-GP- 18 was 52.81MBq/mg.The radiochemical purity of ^125I-GP- 18 was （93.48 ± 1.20）% in 4℃ NS after 48h but which declined to （71.94 ± 5.47）%（P〈0.01） after two hours of mixing with human serum. Conclusion GP-18 can be labeled with ^125I,the product is of a high radioehemieal purity but low stability in 37℃ human serum.