The preparation and biological evaluation of 131 I labeling anti-B7-H3 monoclonal antibody 4H7

Abstract

Objective To assess the radiobiological effect of 131 I labeled recombinant human B7-H3 monoclonal antibody(131 I-4H7)in nude mice with human renal cell carcinoma(RCC). Methods Chloramine-T method was used for 131 I labeling 4H7. Labeling efficiency, radiochemical purity and stability were estimated by using paper chromatography method.The activity and tumor uptake of 131 I-4H7 were measured by tissue distribution assay and single-photon emission computed tomography(SPECT)imaging after injection of 131 I-4H7. Results The labeling efficiency and radiochemical purity of 131 I-4H7 were 61. 64% and 98. 4%, respectively.The in vivo distribution and elimination of 131 I-4H7 were consistent with a first-order and two-compartment model, t1/2α= 27. 94 min, t1/2β= 1634. 74 min.The metabolism of 131 I-4H7 mainly depended on liver and kidney.The tissue distribution assay and SPECT imaging showed that 131 I-4H7 was markedly absorbed by the tumor and reached its maximal uptake rate (3. 15% ID/g)at 24 hours.Compared with the Na131 I group, the 131 I-4H7 group showed higher uptake of 131 I at each time point. Conclusion The labeling rate and radiochemical purity of 131 I-4H7 is high,simple and the stability of 131 I-4H7 is fine. Key words: B7-H3; Isotope labeling; Renal cell carcinoma; Biological distribution; Radionuclide imaging