Preparation of TH227-labeled radioimmunoconjugates, assessment of serum stability and antigen binding ability

Cancer Biother Radiopharm. 2007 Jun;22(3):431-7. doi: 10.1089/cbr.2006.321.


In this study, the feasibility of constructing radioimmunoconjugates by using the novel therapeutic candidate alpha-emitter, (227)Th, was evaluated. By use of the bifunctional chelator, p-SCN-benzyl-DOTA, (227)Th was conjugated to the two monoclonal antibodies, rituximab and trastuzumab. Their stability in 80% fetal bovine serum at 37 degrees C was measured. The immunoreactive fractions were determined by using CD20- and HER/2-positive cells, respectively. The overall labeling yield spanned from 6% to 17%. The radioimmunoconjugates demonstrated a relevant stability in serum and showed appropriate antigen-binding abilities.

MeSH terms

  • Antibodies, Monoclonal / blood
  • Antigens
  • Cell Line, Tumor
  • Drug Stability
  • Heterocyclic Compounds, 1-Ring
  • Humans
  • Immunoconjugates / blood*
  • Indicators and Reagents
  • Thorium / blood
  • Thorium / immunology*


  • Antibodies, Monoclonal
  • Antigens
  • Heterocyclic Compounds, 1-Ring
  • Immunoconjugates
  • Indicators and Reagents
  • 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid
  • Thorium