Use of paramagnetic chelated metal derivatives of polysaccharides and spin-labeled polysaccharides as contrast agents in magnetic resonance imaging

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Magnetic Resonance in Medicine; (United States)

DOI:https://doi.org/10.1002/mrm.1910170222· OSTI ID:5450701

Bligh, S W; Harding, C T; Sadler, P J; Bulman, R A; Bydder, G M; Pennock, J M; Kelly, J D; Latham, I A; Marriott, J A ^[1]

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1. Department of Chemistry, Birkbeck College, London (England)

Soluble and insoluble polysaccharides were derivatized with diethylenetriaminepentaacetic acid (DTPA) and/or spin-labeled with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Polysaccharides derivatized with DTPA were prepared via cyanogen bromide activation, coupling to a diamine linker, and to DTPA anhydride. Spin-labeled polysaccharides were also prepared via cyanogen bromide activation. The extent of derivatization for dextran (18 kDa) was about 120 glucose units per DTPA, and for cellulose and starch about 15-30 units per DTPA. For spin-labeled polysaccharides, the average loading ranged from 1 nitroxide per 16 glucose units for starch to 181 for dextran (82 kDa). These derivatized paramagnetic polysaccharides were shown to be more effective relaxants than the small paramagnetic molecules alone. Both soluble and insoluble polysaccharide-linker-DTPA-Gd(3) complexes were effectively cleared from the body (rats) after oral administration. After intravenous administration, the biodistribution of dextran-linker-DTPA-Gd(3) complexes differed significantly from that of GdDTPA. Reduction of the nitroxide by ascorbic acid was retarded in the polysaccharide derivatives, particularly in starch derivatized with both nitroxide and linker-DTPA-Cu(2). These agents showed contrast enhancement in the gastrointestinal tract of rabbits.

• OSTI ID: 5450701
• Journal Information: Magnetic Resonance in Medicine; (United States), Journal Name: Magnetic Resonance in Medicine; (United States) Vol. 17:2; ISSN 0740-3194; ISSN MRMEE
• Country of Publication: United States
• Language: English

Related Subjects

550600* -- Medicine
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
ANIMALS
CARBOHYDRATES
CARBOXYLIC ACIDS
CELLULOSE
CHELATING AGENTS
CONTRAST MEDIA
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
DRUGS
DTPA
ELECTRON SPIN RESONANCE
GASTROINTESTINAL TRACT
MAGNETIC RESONANCE
MAMMALS
NMR IMAGING
NUCLEAR MAGNETIC RESONANCE
ORGANIC ACIDS
ORGANIC COMPOUNDS
POLYSACCHARIDES
RABBITS
RADIOPROTECTIVE SUBSTANCES
REAGENTS
RESONANCE
SACCHARIDES
STARCH
VERTEBRATES