Evaluation of a 99mTc-tricine Vascular Disrupting Agent as an <i>In-vivo</i> Imaging in 4T1 Mouse Breast Tumor Model

Abstract

Colchicine as a vascular disrupting agent creates microtubule destabilization whichinduces vessel blockage and consequently cell death. Accordingly, colchicines and itsanalogues radiolabeled with 99mTc may have potential for visualization of tumor. In this work,deacetylcolchicine a colchicine analogue was labeled with 99mTc via tricine as a coligandand characterized for its tumor targeting properties. The in-vitro radiochemical stability andthe biodistribution were studied in 4T1 breast tumor model bearing mice. Labeling yield ofmore than 90% was obtained corresponding to a specific activity of 46 MBq/μmol. In-vivobiodistribution studies demonstrated that radiocomplex had high tumor to muscle and tumor toblood ratios at early time points. Planer gamma imaging of tumor bearing mice showed that thisradioconjugate was able to clearly visualize tumors. According to high tumor uptake, presentedradiocomplex may have a potential for targeted imaging studies.