HYNIC-Anx13 Labelled With ⁹⁹Tc^m for Imaging of Apoptosis

In this report, the ⁹⁹Tc^m labelling of Annexin V fragment modified with HYNIC (HYNIC-Anx13) using Tricine, EDDA or EDDA/Tricine as coligands was described. The effect of various factors on ⁹⁹Tc^m labelling was investigated. Biodistribution studies in normal mice and gamma imaging of apoptosis in rats induced by cyclophosphamide were performed. The labelled conjugates were stable in aqueous solution and serum solution in vitro, but they were not stable when challenged with cysteine and in vivo. ⁹⁹Tc^m labelled HYNIC-Anx13 showed rapid blood clearance and renal excretion. The uptake in target organs in model rats were significantly higher than those in control rats (p<0.05), but the T/NT ratios were relatively low. The imaging result indicated that ⁹⁹Tc^m-HYNIC-Anx13 may not be a promising agent for apoptotic imaging.