Simple Methods for Tracking Stem Cells with (64)Cu-Labeled DOTA-hexadecyl-benzoate.

The purpose of this study was to evaluate (64)Cu-labeled hexadecyl-1,4,7,10-tetraazacyclododecane-tetraacetic acid-benzoate ((64)Cu-DOTA-HB) (1) as positron emission tomography (PET) radiotracer for stem cell imaging. Hexadecyl-DOTA-benzoate (DOTA-HB) (2) was efficiently labeled with (64)Cu (>99%), and cell labeling efficiency with adipose-derived stem cells (ADSCs) was over 50%. Labeling with 1 did not compromise cell viability. In the PET imaging, intramuscularly transplanted 1-labeled ADSCs were monitored for 18 h in normal rat heart. These results indicate that 1 can be utilized as a promising radiotracer for monitoring of transplanted stem cells.