期刊名称：Journal of Radiation Research and Applied Sciences
印刷版ISSN：1687-8507
出版年度：2016
卷号：9
期号：4
页码：441-448
DOI：10.1016/j.jrras.2016.07.001
出版社：Elsevier B.V.
摘要：Abstract The use of trastuzumab as intact IgG labeling radionuclide for {HER2} positive breast cancer theranostic agent is not ideal because it is slowly eliminated from the blood and normal tissues resulting in low tumor/blood (T/B) and tumor/normal tissue (T/NT) ratios. To overcome this limitation, we developed the trastuzumab F(ab′)2 fragments and radiolabeling of the fragments by β and γ-particle of Lutetium-177. F(ab)2 fragments were produced by digestion of trastuzumab IgG (Herceptin) with pepsin for 18 h at 37 °C. The F(ab′)2 fragment fractionated in PD-10 column, followed by the conjugation with 2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (p-SCN-Bn-DOTA) as a metal chelator and radiolabeling with 177LuCl3. Molecular weight of fragments was calculated by {LCMS} (Liquid Chromatography Mass Spectroscopy) and the radiochemical purity was evaluated by ITLC-SG (Instan Thin Layer Chromatography). Our study showed that the purity of F(ab′)2 fragment generated by PD-10 fractions was >98% and the molecular weight of F(ab′)2 was 98.35 kDa. The average numbers of pSCN-Bn-DOTA chelates per antibody fragment were 5.03 ± 1.5 and the optimum conjugation reactions was performed at molar ratio 20:1 (chelator to antibody). The stability test of the radioimmunoconjugate in the human serum albumin (HSA) at 37 °C showed the radiochemical purity was 91.96 ± 0.26% after 96 h storage. This indicated that the radioimmunoconjugate is relatively stable when applied to the human body's physiological condition.
关键词：Trastuzumab F(ab′)2; Radioimmunoconjugate; Lutetium-177; Breast cancer
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