AIM To directly radiolabel an anti-hepatomamAb fragment HAb18 F（ab’）<sub>2</sub> with <sup>99m</sup>Tc bystannous-reduced method,and assess thestability,biodistribution and radioimmun-oimag...AIM To directly radiolabel an anti-hepatomamAb fragment HAb18 F（ab’）<sub>2</sub> with <sup>99m</sup>Tc bystannous-reduced method,and assess thestability,biodistribution and radioimmun-oimaging（RⅡ）.METHODS Immunoreactive fraction wasdetermined according to Lindmo’s method.Ellman’s reagent was used to determine thenumber of thiols in the reduced F（ab’）<sub>2</sub>.Labelingefficiency and homogeneity were measured bypaper chromatography,sodium dodecylsulphatepolyacrylamide gel electrophoresis（SDS-PAGE）and autoradiography.Challenge assay involvedthe incubation of aliquots of labeled antibody inethylenediaminetetraacetate（ EDTA ）and L-cysteine（L-cys）solutions with different molarratio at 37℃ for 1h,respectively.Investigationsin vivo utilized nude mice bearing humanhepatocellular carcinoma（HHCC）xenograftswith gamma camera imaging and tissuebiodistribution studies at regular intervals.RESULTS The labeling procedure was finishedwithin 1.5 h compared with the'pretinning'method which would take at least 21h.In vitrostudies demonstrated that the radiolabeled mAbfragment was homogeneous and retained itsimmunoreactivity.Challenge studies indicatedthat <sup>99m</sup>Tc-labeled HAb18 F（ab’）<sub>2</sub> in EDTA is morestable than in L-cys.Imaging and biodistribution showed a significant tumor uptake at 24 h post-injection of <sup>99m</sup>Tc-labeled HAb18 F（ab’）<sub>2</sub>.Theblood,kidney,liver and tumor uptakes at 24hwere 0.56±0.09,56.45±11.36,1.43±0.27 and6.57±3.01（%ID/g）,respectively.CONCLUSION <sup>99m</sup>Tc-HAb18 F（ab’）<sub>2</sub> conjugateprepared by this direct method appears to be aneffective way to detect hepatoma in nude micemodel.展开更多
基金National Natural Science Foundation of China,No.39700175
文摘AIM To directly radiolabel an anti-hepatomamAb fragment HAb18 F（ab’）<sub>2</sub> with <sup>99m</sup>Tc bystannous-reduced method,and assess thestability,biodistribution and radioimmun-oimaging（RⅡ）.METHODS Immunoreactive fraction wasdetermined according to Lindmo’s method.Ellman’s reagent was used to determine thenumber of thiols in the reduced F（ab’）<sub>2</sub>.Labelingefficiency and homogeneity were measured bypaper chromatography,sodium dodecylsulphatepolyacrylamide gel electrophoresis（SDS-PAGE）and autoradiography.Challenge assay involvedthe incubation of aliquots of labeled antibody inethylenediaminetetraacetate（ EDTA ）and L-cysteine（L-cys）solutions with different molarratio at 37℃ for 1h,respectively.Investigationsin vivo utilized nude mice bearing humanhepatocellular carcinoma（HHCC）xenograftswith gamma camera imaging and tissuebiodistribution studies at regular intervals.RESULTS The labeling procedure was finishedwithin 1.5 h compared with the'pretinning'method which would take at least 21h.In vitrostudies demonstrated that the radiolabeled mAbfragment was homogeneous and retained itsimmunoreactivity.Challenge studies indicatedthat <sup>99m</sup>Tc-labeled HAb18 F（ab’）<sub>2</sub> in EDTA is morestable than in L-cys.Imaging and biodistribution showed a significant tumor uptake at 24 h post-injection of <sup>99m</sup>Tc-labeled HAb18 F（ab’）<sub>2</sub>.Theblood,kidney,liver and tumor uptakes at 24hwere 0.56±0.09,56.45±11.36,1.43±0.27 and6.57±3.01（%ID/g）,respectively.CONCLUSION <sup>99m</sup>Tc-HAb18 F（ab’）<sub>2</sub> conjugateprepared by this direct method appears to be aneffective way to detect hepatoma in nude micemodel.
