Optimization of the preparation of 99mTc-labeled Hynic-derivatized Annexin V for human use

Hydrazino nicotinate (Hynic) is one of the most attractive bifunctional agents designed for the labeling of proteins with Tc-99m. Recently, a Tc-99m-labeled Hynic-Annexin V derivative has been described and successfully evaluated in animal models of apoptosis. Prior to a phase I human study, the preparation of Tc-99m-Hynic-Annexin V has been optimized. The influence of the Hynic-load of Annexin V, amount of protein, nature and amount of reducing agent, activity and co-ligand on the labeling yield were evaluated using ITLC and size-exclusion FPLC. Optimal labeling yields were obtained when 60-90 mug Hynic-Annexin V was labeled with up to 1.11 GBq (30 mCi) (TcO4)-Tc-99m-using 10-20 mug SnCl2.2H(2)O as reducing agent and 1.5 mg tricine as the co-ligand. Biodistribution in normal mice was comparable to literature data. (C) 2003 Elsevier Inc. All rights reserved.