Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates
Autor(a) principal: | |
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Data de Publicação: | 2001 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/10373 https://doi.org/10.1021/bc000065r |
Resumo: | Two linear polyamide conjugates of Gd(DTPA)2- were synthesized and characterized by high-resolution nuclear magnetic resonance (NMR) spectroscopy and size exclusion chromatography (SEC). DTPA was copolymerized with two different diamines, 1,6-hexanediamine and trans-1,4-cyclohexanediamine, yielding the polymers DTPA-HMD and DTPA-CHD, with low polydispersity. Their molecular flexibility in solution was studied using 13C spin−lattice relaxation time measurements, indicating that the cyclohexanediamine linking moiety of the DTPA-HMD polymer is more rigid than that of DTPA-CHD. The influence of the flexibility of the linking functionalities on the relaxivity of the Gd3+-DTPA-polymer conjugates was studied by water nuclear magnetic relaxation dispersion (NMRD). The relaxivity of the Gd(DTPA-CHD) polymer was only slightly higher than that of the Gd(DTPA-HMD) polymer, and only two times higher than the usual values for small Gd-DTPA-like chelates. The low relaxivities obtained for both polymers, much lower than expected from the polymer apparent molecular weights, result from their substantial residual flexibility, and also from a too long, nonoptimal, value of the inner-sphere water exchange rate. These polymeric compounds are also cleared very quickly from the blood of rats, indicating that they are of limited value as blood pool contrast agents for MRA. |
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Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer ConjugatesTwo linear polyamide conjugates of Gd(DTPA)2- were synthesized and characterized by high-resolution nuclear magnetic resonance (NMR) spectroscopy and size exclusion chromatography (SEC). DTPA was copolymerized with two different diamines, 1,6-hexanediamine and trans-1,4-cyclohexanediamine, yielding the polymers DTPA-HMD and DTPA-CHD, with low polydispersity. Their molecular flexibility in solution was studied using 13C spin−lattice relaxation time measurements, indicating that the cyclohexanediamine linking moiety of the DTPA-HMD polymer is more rigid than that of DTPA-CHD. The influence of the flexibility of the linking functionalities on the relaxivity of the Gd3+-DTPA-polymer conjugates was studied by water nuclear magnetic relaxation dispersion (NMRD). The relaxivity of the Gd(DTPA-CHD) polymer was only slightly higher than that of the Gd(DTPA-HMD) polymer, and only two times higher than the usual values for small Gd-DTPA-like chelates. The low relaxivities obtained for both polymers, much lower than expected from the polymer apparent molecular weights, result from their substantial residual flexibility, and also from a too long, nonoptimal, value of the inner-sphere water exchange rate. These polymeric compounds are also cleared very quickly from the blood of rats, indicating that they are of limited value as blood pool contrast agents for MRA.American Chemical Society2001-03-21info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/10373http://hdl.handle.net/10316/10373https://doi.org/10.1021/bc000065rengBioconjugate Chemistry. 12:2 (2001) 170-1771043-1802Duarte, M. G.Gil, M. H.Peters, J. A.Colet, J. M.Elst, L. VanderMuller, R. N.Geraldes, C. F. G. C.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2021-10-12T09:19:38Zoai:estudogeral.uc.pt:10316/10373Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:55:46.393324Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
title |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
spellingShingle |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates Duarte, M. G. |
title_short |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
title_full |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
title_fullStr |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
title_full_unstemmed |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
title_sort |
Synthesis, Characterization, and Relaxivity of Two Linear Gd(DTPA)−Polymer Conjugates |
author |
Duarte, M. G. |
author_facet |
Duarte, M. G. Gil, M. H. Peters, J. A. Colet, J. M. Elst, L. Vander Muller, R. N. Geraldes, C. F. G. C. |
author_role |
author |
author2 |
Gil, M. H. Peters, J. A. Colet, J. M. Elst, L. Vander Muller, R. N. Geraldes, C. F. G. C. |
author2_role |
author author author author author author |
dc.contributor.author.fl_str_mv |
Duarte, M. G. Gil, M. H. Peters, J. A. Colet, J. M. Elst, L. Vander Muller, R. N. Geraldes, C. F. G. C. |
description |
Two linear polyamide conjugates of Gd(DTPA)2- were synthesized and characterized by high-resolution nuclear magnetic resonance (NMR) spectroscopy and size exclusion chromatography (SEC). DTPA was copolymerized with two different diamines, 1,6-hexanediamine and trans-1,4-cyclohexanediamine, yielding the polymers DTPA-HMD and DTPA-CHD, with low polydispersity. Their molecular flexibility in solution was studied using 13C spin−lattice relaxation time measurements, indicating that the cyclohexanediamine linking moiety of the DTPA-HMD polymer is more rigid than that of DTPA-CHD. The influence of the flexibility of the linking functionalities on the relaxivity of the Gd3+-DTPA-polymer conjugates was studied by water nuclear magnetic relaxation dispersion (NMRD). The relaxivity of the Gd(DTPA-CHD) polymer was only slightly higher than that of the Gd(DTPA-HMD) polymer, and only two times higher than the usual values for small Gd-DTPA-like chelates. The low relaxivities obtained for both polymers, much lower than expected from the polymer apparent molecular weights, result from their substantial residual flexibility, and also from a too long, nonoptimal, value of the inner-sphere water exchange rate. These polymeric compounds are also cleared very quickly from the blood of rats, indicating that they are of limited value as blood pool contrast agents for MRA. |
publishDate |
2001 |
dc.date.none.fl_str_mv |
2001-03-21 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/10373 http://hdl.handle.net/10316/10373 https://doi.org/10.1021/bc000065r |
url |
http://hdl.handle.net/10316/10373 https://doi.org/10.1021/bc000065r |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Bioconjugate Chemistry. 12:2 (2001) 170-177 1043-1802 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799133843868876800 |