[Frontiers in Bioscience 16, 2527-2539, June 1, 2011]
Experimental study of 99mTc-depreotide eparation and its affinity with A549 cell
Wei Xia1,2, Xiaoping Zhang1, Fei Yu1, Peijun Wang3, Haidong Cai1, Renhua Hou1, Guoyu Wang2, Xueyu Yuan1, Zhongwei LV1
1Department of Nuclear Medicine, 10th People's Hospital, Tongji University of Medcine School, Shanghai 200072, China, 2Department of Nuclear Medicine, Shanghai Putuo Distict People's Hsopital, Shanghai 200060,China, 3Department of Radiology, Tongji Hospital,Tongji University,Shanghai 200071, China
TABLE OF CONTENTS
1. ABSTACT The 99mTc-labeled agent, (99mTcO)depreotide, has received regulatory approval in the United States and Europe for use in the detection of cancer. It is essential to establish a simple and reliable method of direct radiolabeling of 99mTc-depreotide and to investigate its specific receptor binding properties with human non small cell lung cancer (NSCLC) A549 cell in vitro. So we made some researches as follow: Depreotide was labeled with 99mTc using SnCl2 as a reductant. Labeling efficiencies at different pH values and temperatures were compared. Radioreceptor assay was used to observe the uptake kinetics, stagnation and retention half time of 99mTc-depreotide in A549 cells. As the results of the investigation ,many facts is shown below: The labeling rate of pH 6.0 .group was higher than that of pH 5.0 .and pH7.0 .groups. The labeling rate decreased when temperature increased from 15 ° C to 50 ° C. The uptake rate increased with rising temperature, and the maximum uptake was observed at 60min at 37 ° C. ④The cleaning curves were similar at different temperatures, and the half cleaning time at 37 ° C was 48min. The results showed that the optimal conditions for labeling depreotide with 99mTc was found to be below 15 ° C at a pH lower than 6.0. Furthermore, at 37 ° C, 99mTc-depreotid may have the potential as an ideal imaging agent for somatostatin receptors.