A novel technique for the preparation of ¹²⁵I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabino-furanosyl) urail and its biodistribution pattern in Kunming mice

Abstract

In this study, a novel technique for the preparation of ¹²⁵I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, ¹²⁵I-FIAU biodistribution profile was detected in Kunming mice and the possibility of using FTAU radio-labeling for reporter gene imaging was explored. 5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FTAU) was labeled with radioiodine (¹²⁵I). A rotary evaporation method was used to remove excess methanol. The reactant was purified through a Sep-Pak C18 reversal phase column. The radiochemical purity and in vivo stability were determined using silica gel thin layer chromatography (TLC). The biodistribution of ¹²⁵I-FIAU in Kunming mice was also detected. The results showed that ¹²⁵I-FIAU could be radiolabeled effectively with FTAU, with mean labeling rate being (81±0.38)% (n =5). The mean radiochemical purity of (98.01±0.40)% (n=5) was achieved after a reversal phase Sep-park column purification. ¹²⁵I-FIAU was stable when incubated in normal human serum or in saline at 37°C, with a radiochemical purity >96% during a 0.5–24 h time period. Biological experiments exhibited rapid clearance of ¹²⁵I-FIAU from the blood pool. ¹²⁵I-FIAU was mostly excreted by kidneys. ¹²⁵I-FIAU in myocardium dropped conspicuously after 8 h and there was hardly retention at 24 h. We were led to concluded that the new method of radioiodinization of FTAU for the preparation of ¹²⁵I-FIAU is easy, highly effective and stable in vivo. The biodistribution of ¹²⁵I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.

Keywords

reporter gene / FTAU / radioiodine labeling / biodistribution

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