The biological characterization of (99m)Tc-BnAO-NI as a SPECT probe for imaging hypoxia in a sarcoma-bearing mouse model.

Objectives: Tumor growth beyond the region where vascular oxygen can reach creates a hypoxic domain. In this study, BnAO, a ligand that had been labeled with (99m)Tc-pertechnetate for hypoxia imaging, was conjugated with 2-nitroimidazole to give 3,3,10,10-tetramethyl-1-(2-nitro-1H-imidazo-1-y1)-4,9-diazadodecane-2,11- dionedioxime (BnAO-NI) as a potential ligand for hypoxia detection. Pentoxifylline is a peripheral vasodilator and has been used as a radiosensitizer in tumor radiotherapy.

The preparation and biological characterization of a new HL91-derivative for hypoxic imaging on stroke mice.

Aim: (99m)Tc-HL91 (Prognox, GE-Healthcare) was the first nonnitro-aryl-based radiotracer for evaluating hypoxic fraction in neoplasm, stroke and myocardium infarction regions. However, the high hydrophilicity of (99m)Tc-HL91 might hamper its penetration into cells. In this study, we prepared a new ligand 4,4,11,11-tetramethyl- 5,10-diazatetradecane- 3,12-dionedioxime (HL91-ET) with higher lipophilicity but structurally similar compared with that of HL91.