Preparation and primary bioevaluation of 99mTc-labeled-1-thio-β-D-glucose as melanoma targeting agent.

The development of specific radiolabeled probes towards molecular markers in vivo has gained interest as targeted imaging agents for a more accurate detection of diseases. The aim of this study was to evaluate early detection of melanoma tumor based on 1-thio-β-D-glucose (1-TG) radiolabeled with technetium-99m. 99mTc-1-TG has been synthesized and evaluated in vitro and in vivo for melanoma uptake. Tumor-cell uptake of the 99mTc complex was performed with cultured B16F1 murine melanoma cells which were also used for the in vivo studies. The methodology consisted in radiopharmaceutical synthesis followed by intravenous administration of 99mTc-1-TG in melanoma bearing mice and scintigraphic imaging. 1-thio-β-D-glucose was labeled with 99mTc under reductive conditions using SnCl2. Radiolabeling efficiency was > 96%. 99mTc-1-TG showed high melanoma uptake in vitro. This was confirmed in vivo since a significant difference of 99mTc-1- TG uptake between melanoma model and the control joint was observed. General biodistribution showed renal uptake. The scintigraphic images showed tumor selective uptake of the 1-TG labeled, in tumor-bearing mice This study indicates effective labeling of 1-thio-β-D-glucose with 99mTc that shows potential as a new type of specific probe for melanoma detection.