Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents

Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents PDF Author: ZhiHang Chen
Publisher:
ISBN: 9781361427316
Category :
Languages : en
Pages :

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Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents

Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents PDF Author: ZhiHang Chen
Publisher:
ISBN: 9781361427316
Category :
Languages : en
Pages :

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Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents

Lanthanide Complexes for Luminescent Materials and the Magnetic Resonance Imaging (MRI) Contrast Agents PDF Author: Zhihang Chen
Publisher:
ISBN:
Category : Contrast media (Diagnostic imaging)
Languages : en
Pages : 406

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Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Luminescent Sensors

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Luminescent Sensors PDF Author: Cong Li
Publisher: Open Dissertation Press
ISBN: 9781374708921
Category :
Languages : en
Pages :

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This dissertation, "Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Luminescent Sensors" by Cong, Li, 李聰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled LANTHANIDE COMPLEXES FOR MAGNETIC RESONANCE IMAGING (MRI) CONTRAST AGENTS AND LUMINESCENT SENSORS Submitted by Li Cong for the degree of Doctor of Philosophy at The University of Hong Kong in June 2004 Magnetic resonance imaging (MRI) and bioluminescence imaging are widely used in medical diagnosis. There is a need to develop MRI contrast agents and 3+ 3+ luminescence sensors with higher sensitivity and specificity. Novel Gd and Tb complexes endowed with different functionalities have been synthesized and studied. In this work, a series of general and straightforward methods for the preparation of mono, 1,4 bis and tris N-alkylation of cyclen in high yields and with unprecedented regioselectivity were developed. These protocols are useful in introducing different functional groups to the 1,4,7,10-tetraazacyclododecane (cyclen) in a single step without the use of unnecessary protecting groups. For example, the functionalised 1,4,7-tris-(acetic acid)-1,4,7,10-tetraazacyclododecane (DO3A) derivatives that used to be prepared by multiple steps can now be achieved in two simple steps with attractive features such as high yield, operational convenience and cost economy. 3+ The novel mononuclear Gd polyaminocarboxylates based on cyclen, GdL1- GdL7, were synthesized. Functional groups, such as crown ethers with different ring sizes, β-D-glucopyranose, guanidinium and quinine alkylated diaza-18C6, were introduced into these complexes to achieve target-specificity. The synthesis, structural 1 13 characterization measured by single crystal X-ray analysis, H and C NMR, ESI-MS, HRFAB-MS and elemental analysis, luminescence-lifetime measurements, the relaxometric investigations of the complexes by nuclear magnetic resonance 17 dispersion (NMRD) profiles, variable-temperature O NMR transverse relaxation and pH dependence relaxivity, in vivo MRI studies and in vitro toxicity studies were 3+ discussed. Relaxivities of the four Gd complexes, GdL1, GdL3, GdL5 and GdL6 -1 -1 -1 -1 are in the descending order of GdL1 (9.65 mM s ) > GdL3 (9.36 mM s ) > GdL6 -1 -1 -1 -1 (7.34 mM s ) > GdL5 (3.75 mM s ) measured at 20 MHz and 25C. Compared to -1 -1 the commercially available contrast agents [Gd(DOTA)(H O)] (4.74 mM s ) and -1 -1 [Gd(DO3A)(H O) ] (5.72 mM s ) with two bound water molecules, GdL1, GdL3 2 2 and GdL6 showed much higher relaxivity. The most striking result is the water molecule exchange lifetime of GdL1, which was measured as 55 ns, very close to the optimum value of 20-30 ns in theory. GdL1, GdL3 and GdL6 also demonstrated outstanding performances in the MRI studies based on small animals. The maximal renal and hepatic intensity enhancements (IE) induced by GdL1 were 200% and 105% respectively above the control level, and much higher than those of Gd-DOTA at 123% and 70%. Moreover, GdL1 and GdL3 afforded much longer resident lifetimes in the kidney cortex and liver parenchyma. It is noteworthy that GdL1 showed obvious target-specificity to liver tissue. The maximal hepatic IE induced by GdL1 with low dosage (90%, 0.03 mmol/kg) is even higher than that of Gd-DOTA with three times dosage (70%, 0.1 mmol/kg). Furthermore, an in vitro MTT assay confirmed that the cytotoxicity of GdL1 is quite low even at high concentration (10 mM). The luminescent properties of TbL1, TbL3 and TbL7 were investigated in aqueous solution. TbL

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Luminescent Sensors

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Luminescent Sensors PDF Author: Cong Li (Ph.D.)
Publisher:
ISBN:
Category : Chemiluminescence
Languages : en
Pages : 468

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Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents PDF Author: Pui-Ling Tong
Publisher: Open Dissertation Press
ISBN: 9781374698079
Category :
Languages : en
Pages :

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This dissertation, "Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents" by 湯佩玲, Pui-ling, Tong, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b4257621 Subjects: Magnetic resonance imaging Lanthanum compounds Contrast media

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Fluorescence Probes

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Fluorescence Probes PDF Author: Ho-Hon Arthur Leung
Publisher: Open Dissertation Press
ISBN: 9781361289853
Category :
Languages : en
Pages :

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This dissertation, "Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Fluorescence Probes" by Ho-hon, Arthur, Leung, 梁浩瀚, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: In this work, novel Gd(III) complexes endowed with non-steroidal anti-inflammatory drugs (NSAIDs) were synthesised and their targeting properties towards sites of inflammation were studied in U87 xenograft and rheumatoid arthritis animal models. The Tb(III) analogues were also synthesised and their photophysical properties were studied. Six new Gd(III) DO3A-amide complexes bearing different linkers, ethylenediamine (GdL1), hexamethylenediamine (GdL2), 2,2'-oxydiethylamine (GdL3), 4,7,10-trioxa-1,13-tridecanediamine (GdL4), trans-1,4-cyclohexanediamine (GdL5), and 1,4-phenylenediamine (GdL6) were incorporated to mefenamic acid (MA) moiety, a common NSAID. The syntheses, relaxometric properties by NMR techniques, hydration number determinations by luminescence lifetime measurements, lipophilicities by UV-Vis spectrometry, serum albumin binding properties by tryptophan emission-quenching experiments, cytotoxicities by MTT assay, cellular uptake properties; MRI scans on U87 sxenograft and rheumatoid arthritis animal models, and biodistributions of these new complexes were discussed. GdL1-L6 possess one bound water molecule and GdL2-L5 show higher relaxivities than Gd-DOTA (4.21 mM?1s?1, 300 MHz, 25oC), a clinically used MRI contrast agent (CA). The relaxivities at 300 and 400 MHz respectively at 25oC are in the descending order of GdL4 (5.70 and 4.87 mM?1?1) > GdL3 (4.94 and 4.07 mM?1s?1) > GdL2 (4.60 and 4.07 mM?1s?1) > GdL5 (4.41 and 4.12 mM?1s?1) > GdL6 (3.98 and 3.31 mM?1s?1) > GdL1 (3.96 and 3.56 mM?1s?1). GdL1-L5 show low cytotoxicities towards HeLa cells at 1000 μM. The MRI scans of GdL1-L6 on U87 xenograft show strong intensity boost immediately after administration. The intensity enhancements persist for more than 90 mins and complete clearances are found after 24 h post-administration. Their MRI scans on arthritis model also show prolonged retention. It is concluded that the retention is related to the targeting on inflammatory mediators of the complexes. All complexes show superior retention and intensity enhancements in kidney, liver, tumour and arthritis joint than Gd-DOTA. GdL1-L6 are therefore potential candidates as universal MRI CAs. Three new Gd(III) DO3A-amide complexes bearing respectively benzoic acid (GdL7), salicylic acid (GdL8), and methylated salicylic acid (GdL9), one known Gd(III) DTPA-bissalicylic acid (GdL10) complex and one new Gd(III) DTPA-bismethylated salicylic acid (GdL11) were synthesised and investigated. Their syntheses, relaxivities, hydration numbers, pH dependent photophysical properties, cytotoxicities, cellular uptake properties and MRI scans on arthritis rat model were discussed. All GaL7-L11 possess one bound water molecule and show lower relaxivities than Gd-DOTA. The relaxivities at 300 MHz at 25oC are in the descending order of GdL10 (3.64 mM?1s?1) > GdL9 (3.53 mM?1s?1) > GdL11 (2.69 mM?1s?1) > GdL8 (2.10 mM?1s?1) > GdL7 (1.99 mM?1s?1). Their Tb(III) analogue (TbL7-L11) show pH dependent UV-Vis and photoluminescence spectra which are consequences of protonation or deprotonation of the carboxylic acid, hydroxyl and amide groups. It is concluded that the pH change alters energy transfer efficiency and the ligand triplet energy level. GdL7-L11 show low cytotoxicities in MTT assay. Specifically, GdL8 is examined on arthritis rat model to give a comparable intensity at the arthritis joint to Gd-DOTA but

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Fluorescence Probes

Lanthanide Complexes for Magnetic Resonance Imaging (MRI) Contrast Agents and Fluorescence Probes PDF Author: Ho-hon Leung (Arthur)
Publisher:
ISBN:
Category : Fluorescent probes
Languages : en
Pages : 568

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Lanthanides

Lanthanides PDF Author: Peng Cheng
Publisher: Elsevier
ISBN: 0128222514
Category : Science
Languages : en
Pages : 770

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Book Description
Lanthanides: Fundamentals and Applications provides the fundamentals, new research, promising applications and future outlooks of lanthanide compounds and lanthanide-based materials. The book begins with an introduction, including key concepts, oxidation states and sources, extraction and separation of the lanthanides, followed by spectroscopic and magnetic properties, and metals, crystals and compounds. Organometallic compounds, coordination compounds, molecular magnetic materials and luminescent materials are covered before a discussion of specific lanthanide applications. Spintronics, bioimaging, photoelectric materials, catalysis and nuclear applications are discussed. This comprehensive resource is ideal for researchers and students studying inorganic and materials chemistry, in both academia and industry. - Includes comprehensive and in-depth coverage of lanthanides - Features the most current research progress on lanthanides - Covers a combination view of fundamental research and specific applications of the lanthanides, including spintronics, bioimaging and additives for photoelectric materials

Highly Luminescent Lanthanide Complexes with Specific Coordination Structures

Highly Luminescent Lanthanide Complexes with Specific Coordination Structures PDF Author: Kohei Miyata
Publisher: Springer Science & Business Media
ISBN: 4431549447
Category : Science
Languages : en
Pages : 100

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Book Description
This thesis deals with strongly luminescent lanthanide complexes having novel coordination structures. Luminescent lanthanide complexes are promising candidates as active materials for EL devices, lasers, and bio-sensing applications. The organic ligands in lanthanide complexes control geometrical and vibrational frequency structures that are closely related to the luminescent properties. In most of the previous work, however, lanthanide complexes have high-vibrational frequency C–H units close to the metal center for radiationless transition. In this thesis, the luminescent properties of lanthanide complexes with low-vibrational frequency C–F and P=O units are elucidated in terms of geometrical, vibrational, and chemical structures. The author also describes lanthanide coordination polymers with both high thermal stability (decomposition point > 300°C) and strong-luminescent properties (emission quantum yield > 80%). The author believes that novel studies on the characteristic structures and photophysical properties of lanthanide complexes may open up a frontier field in photophysical, coordination and material chemistry.

Lanthanide Complexes Containing Macrocyclic Ligands for Magnetic Resonance Imaging Contrast Agents

Lanthanide Complexes Containing Macrocyclic Ligands for Magnetic Resonance Imaging Contrast Agents PDF Author: Kam-Cheung Wong
Publisher:
ISBN: 9781374800052
Category :
Languages : en
Pages :

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