Preparation and biodistribution of 1-((2-methoxyphenyl) piperazine)ferrocenecarboxamide labeled with technetium-99m as a potential brain receptor imaging agent.

The goal of this study is to develop a novel brain receptor imaging agent. This study reports the synthesis, characterization and the biological evaluation of 1-((2-methoxyphenyl) piperazine)ferrocenecarboxamide labeled with technetium-99 m ((99m)Tc-MP). The (99m)Tc-MP was obtained quickly (radiolabelling time < 5 min), in 90% yield. The (99m)Tc-complex, characterized by HPLC (20-50% ACN of 0 at 5 min then 50% ACN of 5 at 17 min to finally with 50 at 20% ACN of 17 at 20 min), is stable, neutral and lipophilic enough to cross the blood-brain barrier which was confirmed by octanol/water partition coefficient (LogP = 1.82). In vivo biodistribution indicated that this complex had exceptional brain uptake (2.47% ID/g at 5 min and 0.75% ID/g at 60 min). The distribution of the activity at 15 min post-injection in various rat brain regions showed a higher accumulation in the hippocampus area. After blocking with 8-hydroxy-2-(dipropylamino) tetralin, the uptake of hippocampus was decreased significantly from 0.87% ID/g to 0.21% ID/g at 15 min p.i., while the cerebellum had no significant decrease. The new (99m)Tc-cyclopentadienyltricarbonyl technetium complex reported here showed promising biological results, making it an interesting starting point for the development of a new (99m)Tc-complex as brain receptor imaging agent.

Synthesis and evaluation of 99mTc-N-sulfanilamide ferrocene carboxamide as bacterial infections detector.

A technetium-99m-labeled derivative from sulfanilamide, further referred to as (99m)Tc-N-SFC, targeting infections in experimental animals, has been synthesized. The biological features of this radioactive agent have also been studied. The N-sulfanilamide ferrocene carboxamide (N-SFC) was chemically synthesized and then labeled with technetium-99m. It has been confirmed through this work that it is stable and obtained with radiolabelling yield (>87%). Radiochemical analyses of (99m)Tc-N-SFC revealed that the molecule was labeled rapidly (within 2 min) and effectively with little free pertechnetate in the preparations containing purified compound. Furthermore, in vitro investigations were conducted and the label's stability in serum was observed up to 24 h of testing. Uptake of the tracer with live and heat/killed bacteria was compared in physiological conditions and was about 69% and 61.9% for the Escherichia coli and Staphylococcus aureus strains, respectively. We concluded that synthesis and labeling of Sulfanilamide derivative with (99m-)Tc by this method is rapid, efficient and safe. Biodistribution studies demonstrated that our radiolabeled compound is accumulated rapidly and significantly (P<.05) at infection sites. The comparison of the (99m)Tc-N-SFC accumulation at sites of S. aureus-infected animals, which is expressed as target-to-non-target ratio, (2.88 ± 0.10) with other radiotracers was discussed.