Preparation of [In-111]-labeled-DTPA-bombesin conjugates at high specific activity and stability: Evaluation of labeling parameters and potential stabilizers

Pujatti, P.B.; Massicano, Adriana V F; Mengatti, Jair; Araújo, Elaine Bortoleti de

doi:10.1016/j.apradiso.2012.02.064

Cited by 6 publications

(5 citation statements)

References 20 publications

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“…The conjugation of indium-111 with many polypeptides such as bombesin 150,151 has been reviewed, and whilst it can be achieved by the use of DOTA the use of an improved chelator, 152 benzyl-1-oxa-4,7,10,triazacyclododecane-N,N 0 ,N 0 0 -triacetic acid has been advocated. The fabrication of polymersomes 153 with well-defined diameters (100-200 nm) allows surface modifications to be made so that indium-111 can now be chelated onto the surface of the nanospheres (neat!…”

Section: Technetium (Tc 99m )mentioning

confidence: 99%

Radiochemistry

Urch

2013

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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In this year's review of recent progress in radiochemistry, new radiochemical methods for isotope production, advances in labelling procedures, radioactive isotopes in the environment and miscellaneous topics of radiochemical interest, will be covered but not radiation chemistry, neutron activation analysis and the chemistry of elements that happen to be radioactive. HighlightsThe incorporation of radioisotopes into, sometimes onto, nanoparticles, is becoming increasingly important in nuclear medicine, for therapy and also in diagnosis (ref. 108, 109, 148, 149, 153 and 261-264). Another important piece of work was the use of density functional theory to predict the properties and behaviour of a labelled molecule (ref. 130). General introductionIt is with great sadness that the death of Michael J. Welch in May of 2012 must be recorded. He it was who brought radiochemistry to the medical world, who demonstrated, to a sceptical audience, the potential that radioactive molecules had, when combined with tomography, for diagnosis and tumour location. For forty years he ceaselessly developed nuclear medicine, extending its range to more and more positron emitting isotopes and developing new chemical ways of incorporating them into increasingly complex bio-molecules, 'radiopharmaceuticals'.No new books on radiochemistry in 2012, but a review 1 of the discovery of artificial radioactivity and the report 2 of a conference on the synthesis and applications of labelled compounds have been published. Other conferences have been more focused on specific aspects of the preparation and uses of radioactive compounds, for medical diagnosis and therapy, 3 for autoradiography 4 and to study drug metabolism. 5 A history of the use of radio-iodine has published 6 and the design of bifunctional chelating molecules, 7,8 which can both encapsulate a radioactive atom and join benignly (one hopes so) to a protein or other bio-molecule, reviewed.

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Section: Technetium (Tc 99m )mentioning

confidence: 99%

Radiochemistry

Urch

2013

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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“…Additionally, this can lead to reduced image quality, due to increased non-specific signal. The degree of radiolysis becomes an increasingly important factor with increasing activities, activity concentrations and specific activities [ 19 , 20 , 21 , 22 ]. Additionally, the degree of radiolysis is also influenced by the type of radiation emitted by the chosen radionuclide and the dose rates [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

68Ga-Labeling: Laying the Foundation for an Anti-Radiolytic Formulation for NOTA-sdAb PET Tracers

et al. 2021

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During the preparation of [68Ga]Ga-NOTA-sdAb at high activity, degradation of the tracers was observed, impacting the radiochemical purity (RCP). Increasing starting activities in radiolabelings is often paired with increased degradation of the tracer due to the formation of free radical species, a process known as radiolysis. Radical scavengers and antioxidants can act as radioprotectant due to their fast interaction with formed radicals and can therefore reduce the degree of radiolysis. This study aims to optimize a formulation to prevent radiolysis during the labeling of NOTA derivatized single domain antibody (sdAbs) with 68Ga. Gentisic acid, ascorbic acid, ethanol and polyvinylpyrrolidone were tested individually or in combination to find an optimal mix able to prevent radiolysis without adversely influencing the radiochemical purity (RCP) or the functionality of the tracer. RCP and degree of radiolysis were assessed via thin layer chromatography and size exclusion chromatography for up to three hours after radiolabeling. Individually, the radioprotectants showed insufficient efficacy in reducing radiolysis when using high activities of 68Ga, while being limited in amount due to negative impact on radiolabeling of the tracer. A combination of 20% ethanol (VEtOH/VBuffer%) and 5 mg ascorbic acid proved successful in preventing radiolysis during labeling with starting activities up to 1–1.2 GBq of 68Ga, and is able to keep the tracer stable for up to at least 3 h after labeling at room temperature. The prevention of radiolysis by the combination of ethanol and ascorbic acid potentially allows radiolabeling compatibility of NOTA-sdAbs with all currently available 68Ge/68Ga generators. Additionally, a design is proposed to allow the incorporation of the radioprotectant in an ongoing diagnostic kit development for 68Ga labeling of NOTA-sdAbs.

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“…O pâncreas é um órgão que expressa os receptores BB 2 em alta densidade em camundongos e, portanto, é um controle da ligação dos derivados da bombesina a esses receptores, além de ser também responsável pelo acúmulo abdominal de muitos derivados estudados (Pujatti, 2012 Lu com relação à capacidade de ligação à células tumorais receptorespecíficas.…”

Section: Resultados De Ligação àS Células Tumorais ("Binding")unclassified

“…Além destas características, deve-se levar em conta também a necessidade do radiofármaco de possuir alta atividade específica, ou seja, a radioatividade por unidade de massa do radiofármaco (Pujatti, 2012).…”

Section: Radiofármacos Para Diagnóstico E Terapiaunclassified

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Estudo da marcação com lutécio-177 de derivados da bombesina e avaliação das propriedades biológicas

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Preparation of [In-111]-labeled-DTPA-bombesin conjugates at high specific activity and stability: Evaluation of labeling parameters and potential stabilizers

Cited by 6 publications

References 20 publications

Radiochemistry

Radiochemistry

68Ga-Labeling: Laying the Foundation for an Anti-Radiolytic Formulation for NOTA-sdAb PET Tracers

Estudo da marcação com lutécio-177 de derivados da bombesina e avaliação das propriedades biológicas

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