Production and evaluation of [67Ga]-DTPA-Rituximab
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A. R. Jalilian , L. Mirsadegh , R. Haji-Hosseini , S. Rajabifar , F. Bolurinovin |
, ajalilian@nrcam.org |
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Abstract: (15002 Views) |
Background: In order to obtain an anti-CD20
conjugate to be used in future therapeutic studies with
therapeutic radioisotopes, 67Ga-labeled antibody was
prepared as a model of metal chelated
immunoconjugate for preliminary dosimetric and
biodistribution studies. Materials and Methods:
Rituximab was labeled with [67Ga]-gallium chloride
after residulation with freshly prepared cyclic DTPAdianhydride.
The best results of the conjugation were
obtained by the addition of 1 ml of a rituximab
pharmaceutical solution (5 mg/ml, in phosphate
buffer, pH=8) to a glass tube pre-coated with DTPAdianhydride
(0.01 mg) at 25|o|C with continuous mild
stirring for 30 min. The final isotonic 67Ga-DTPArituximab
complex was checked by gel electrophoresis
for radiolysis/chemolysis control. Radio-TLC was
performed to ensure the formation of only one
species. Preliminary in vivo studies in normal rat
model were performed to determine the
biodistribution of the radioimmunoconjugate up to 6
hours. Results: Radio-thin layer chromatography
showed an overall radiochemical purity of 96-99% at
optimized conditions (specific activity =300-500
MBq/mg, labeling efficiency 77%). Gel electrophoresis
showed no protein cleavage after radiolabeling.
Conclusion: Preliminary in vivo studies in normal rat
model showed [67Ga]-DTPA-rituximab is a good probe
for bio-dosimetry of therapeutic rituximab conjugates.
Iran. J. Radiat. Res., 2007 4 (4): 187-193 |
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Keywords: Gallium-67, rituximab, radiolabeling, biodistribution, cyclotron. |
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Full-Text [PDF 377 kb]
(3420 Downloads)
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Type of Study: Original Research |
Subject:
Radiation Biology
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