Preparation of ¹⁷⁷Lu-DTPA-BIS-BIOTIN and Biodistribution Evaluation in Normal Mice

The labeling method for ¹⁷⁷Lu-DTPA-BIS-BIOTIN was established, and the biodistribution of ¹⁷⁷Lu-DTPA-BIS-BIOTIN in normal mice was carried out as well. Under the optimal experimental condition (DTPA-BIS-BIOTIN 25 μg，pH=4.5 reacting at 80℃ for 20 min), the labeling yield of ¹⁷⁷Lu-DTPA-BIS-BIOTIN is more than 99.0%. ¹⁷⁷Lu-DTPA-BIS-BIOTIN shows pretty good in vitro stability. The biodistribution of ¹⁷⁷Lu-DTPA-BIS-BIOTIN in normal mice shows a rapid blood clearance. The uptake of ¹⁷⁷Lu-DTPA-BIS-BIOTIN is mainly accumulated in liver, spleen and kidney. ¹⁷⁷Lu-DTPA-BIS-BIOTIN is excreted by kidney. The results provide the basis for further study on ¹⁷⁷Lu-DTPA-BIS-BIOTIN used in pretargeted radioimage and radiotherapy of cancer.