Synthesis and biological evaluation of 99mTcCO3IDACPT for tumor imaging

This work reports the synthesis, radiolabeling, and preliminary biodistribution results in tumorbearing mice of 99mTcCO3IDACPT. The novel camptothecin CPT derivate was successfully synthesized by conjugation of iminodiacetic acid IDA to camptothecin via a short carbonylmethylene linker. Radiolabeling was performed in high yield with 99mTcCO3core to get 99mTcCO3IDACPT, which was hydrophilic and stable at room temperature. Biodistribution studies in tumorbearing mice showed that 99mTcCO3IDACPT accumulated in the tumor with good uptake and retention. However, its clearance from normal organs was slow, resulting in poor TNT ratios. Further modification on the linker orand 99mTcchelate to improve the tumortargeting efficacy and in vivo kinetic profiles is currently in progress. Copyright © 2009 John Wiley & Sons, Ltd.