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

Abstract

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.