Radiolabeling of annexin A5 with (99m)Tc: comparison of HYNIC-Tc vs. iminothiolane-Tc-tricarbonyl conjugates.

In the perspective of expanding the use of annexin A5 (anx A5) as radioactive tracer of cell death in vivo, we recently described its radiolabeling with (99m)Tc-tricarbonyl [(99m)Tc(H(2)O)(3)(CO)(3)](+) via the mercaptobutyrimidyl group (anx A5-SH). The aim of the present article was to compare this new method with the HYNIC strategy (anx A5-HYNIC), recognized at present as the reference for the radiolabeling of proteins with (99m)Tc. Similar radiolabeling yields and better chemical stability were obtained with the [anx A5-SH-(99m)Tc-tricarbonyl] complex. Since the [anx A5-HYNIC-(99m)Tc(tricine)(2)] conjugate shows isomeric forms which can affect the biological properties whereas [anx A5-SH-(99m)Tc-tricarbonyl] is less or not prone to such drawback, the latter seems superior to the former. Furthermore, (anx A5-SH) is readily obtained via commercial sources of Traut's reagent whereas (anx A5-HYNIC) is not. The results provide encouraging evidence in the development of anx A5-labeled reagent for apoptose imaging.

How to combine hygiene and radiation protection for radiopharmaceuticals preparation? Analysis in France and propositions.

Radiopharmaceuticals for intravenous administration are considered as sterile medicinal products. Their preparation in hospitals involves adherence to regulations on radiation protection as well as to sterility requirements for parenteral administration. These two basic aspects are often opposite, making the working conditions difficult to define. Official texts that have included hygiene and radiation protection do not precisely state how to combine these two aspects in practice. Thus, after an analysis of the bibliography available, this review will show that even if hospital radiopharmacy departments in France are not able to work in total aseptic environments, some measures can be taken in order to improve preparation conditions.