Radioiodinated doxorubicin as a new tumor imaging model: preparation, biological evaluation, docking and molecular dynamics

Non-invasive molecular imaging techniques are accruing more interest in the last decades. Several radiolabelling elements have been FDA-approved and are currently used to characterize tumors. In this study, the DNA intercalating agent doxorubicin was radiolabelled with 125 I. Several parameters for the radiolabelling reaction were investigated and optimized. A maximum yield of 94 ± 0.3% was reached after reacting 20 μg of doxorubicin with 200 μg Chloramine-T at pH 5 for 30 min. The in vivo stability of 125 I-doxorubicin is validated by the low propensity for thyroid uptake in mice. The preclinical T/NT ratio was approximately 6.4 at 30 min. Docking and molecular dynamics confirmed that the radiolabelling of doxorubicin did not affect (or slightly improved its binding to DNA). Overall, 125 I-doxorubicin was demonstrated to be a promising non-invasive probe for solid tumor imaging. Graphical Abstract