Preparation of ¹²³I and a New ¹²³I Labeled Fusion Peptide

¹²³I with radioactivity of 11.1 TBq/(A•h) and nuclear purity of more than 98.6% was prepared in the CS-30 cyclotron of Sichuan University via ¹²¹Sb（α,2n）¹²³I nuclear reaction by α-energy of 26.5 MeV and using Sb target of 62.2-64.3 mg/cm². Furthermore, V_HCDR₁-V_HFR₂-V_LCDR₃, a new fusion peptide was labeled with ¹²³I, and in vitro and in vivo of the labeled peptide was evaluated. The results show that the labeling yield of ¹²³I V_HCDR₁-V_HFR₂-V_LCDR₃ is more than 90%. The deiodination of ¹²³I labeled V_HCDR₁-V_HFR₂-V_LCDR₃ in vivo is minimal, and ¹²³I V_HCDR₁-V_HFR₂-V_LCDR₃ has a high stability in vitro.