Synthesis and characterization of gadolinium phosphate neutron absorber

Lessing, Paul A.; Erickson, A. W.

doi:10.1016/s0955-2219(03)00100-6

Cited by 38 publications

(25 citation statements)

References 6 publications

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“…That the structure of these deposits in this patient’s skin is representative of those seen in other NSF cases is strongly supported by previously published analyses of thousands of similar deposits in tissues from patients with NSF 11 . The enormous thermodynamic stability of Gd phosphate structures (the solubility product for GdPO 4 .H 2 O has been estimated at 10 −14 ) 14 may provide both an explanation for the formation of these deposits and a challenge to chemists and physicians hoping to treat NSF. It appears reasonable to suppose that these deposits in NSF are either causally related to the disease or at least represent a marker of release of Gd from the chelated GBCA.…”

Section: Discussionsupporting

confidence: 75%

Synchrotron X-ray analyses demonstrate phosphate-bound gadolinium in skin in nephrogenic systemic fibrosis

George

Webb

Abraham

et al. 2010

British Journal of Dermatology

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Background Nephrogenic systemic fibrosis (NSF) is an incurable, debilitating disease found exclusively in patients with decreased kidney function and comprises a fibrosing disorder of the skin and systemic tissues. The disease is associated with exposure to Gadolinium based contrast agents (GBCA) used in magnetic resonance imaging (MRI). Tissue samples from many NSF patients contain micron-sized insoluble Gd-containing deposits. However, the precise composition and chemical nature of these particles is unclear. Objectives To clarify the precise chemical structure of the Gd-containing deposits in NSF tissues. Methods Autopsy skin tissues from a NSF patient are examined in situ using synchrotron x-ray fluorescence (SXRF) microscopy and extended absorption fine structure (EXAFS) spectroscopy and in correlation with light microscopy and the results of SEM/EDS analyses. Results The insoluble Gd deposits are shown to contain Gd no longer coordinated by GBCA chelator molecules but rather in a sodium calcium phosphate material. SXRF microscopy shows a clear correlation between Gd, Ca and P. EXAFS spectroscopy shows a very different spectrum from the GBCAs, with Gd-P distances at 3.11 Å and 3.72 Å as well as Gd-Gd distances at an average of 4.05 Å, consistent with a GdPO4 structure. Conclusions This is the first direct evidence for the chemical release of Gd from GBCA in human tissue. This supports the physical-chemical, clinical, and epidemiological data indicating a link between stability and dose of GBCA to the development of NSF.

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Section: Discussionsupporting

confidence: 75%

Synchrotron X-ray analyses demonstrate phosphate-bound gadolinium in skin in nephrogenic systemic fibrosis

George

Webb

Abraham

et al. 2010

British Journal of Dermatology

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“…1). The resulting free phosphate groups (or phosphoric acid, respectively) and the gadolinium (III) ions now precipitated inside the vesicles as highly insoluble hydrated gadolinium phosphate (GdPO GdPO 4 ·xH 2 O) (29). The main features are encapsulated acid phosphatase (total molecular weight 55 kDa; Sigma-Aldrich, Buchs, CH) and OmpF pore proteins (total molecular weight 110 kDa) that integrate into the polymer membrane.…”

Section: Methodsmentioning

confidence: 99%

“…Inside the polymer vesicles, the hydrolysis of the phosphatase substrate by the encapsulated enzyme results in the production of free phosphate groups (phos-phosphoric acid, respectively), followed by a , followed by a rapid precipitation of the highly water-insoluble hydrated gadolinium phosphate (GdPO GdPO 4 ·xH 2 O) as described by Lessing Nanoreactors based on polymer vesicles from (poly(2-methyloxazoline)-bpoly(dimethylsiloxane)-b-poly(2-methyloxazoline) triblock copolymer building blocks (JW05, total M n 7090 g/mol, 10% with biotin-modified end-groups) were produced as described previously (6). After 24 h, (29). In the next step, 33 mmol/L glucose-1-phosphate (Sigma-Aldrich) and 100 mmol/L gadolinium chloride (GdCl 3 ) (Sigma-Aldrich) were added and the solution was adjusted to pH 5 with 1 mol/L hydrochloric acid.…”

Section: Methodsmentioning

confidence: 99%

Nano Imaging Technologies: Polymer vesicles loaded with precipitated gadolinium nanoparticles: A novel target-specific contrast agent for magnetic resonance imaging

Brož¹,

Ben-Haim²,

Santini³

et al. 2009

European Journal of Nanomedicine

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Gadolinium-based contrast agents for imaging of cellular or subcellular compartments by clinical magnetic resonance imaging (MRI) currently lack a satisfying signal-to-noise ratio and acceptable target specificity. Water-soluble enzyme nanoreactors based on amphiphilic triblock copolymer membranes functionalized with size-selective pore proteins were used to precipitate highly insoluble gadolinium phosphate nanoparticles inside the vesicles. Surface modification with the macrophage scavenger receptor A1 (SRA-1) ligand polyguanylic acid and fluorescence-labeled streptavidin resulted in a novel type of bimodal target-specific contrast agent for MR and fluorescence imaging. Physicochemical analyses showed vesicles with a mean diameter of 46 +/-9 nm and distinguishable particulate content with high electron density. In MRI, the nanocarrier displayed a T1 relaxivity of 3.5e10 L x s(-1) x mmol(-1) vesicles. Uptake to target cells and intracellular localization was proven both with confocal microscopy and MRI. In conclusion, we introduce a novel receptor-targetable gadolinium nanoparticle-based vesicular contrast agent for bimodal imaging in clinical medicine and show its use in first in vitro and cell culture experiments. Broz, P Poe, D Nanomedicine 2009, 2.2:43-48

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“…Firstly, these cations neutralise the negative charges of DNA phosphate groups under a wide range of conditions, and the complexes of rare earth elements with phosphates are practically insoluble (87)(88)(89)(90). Secondly, when interacting with base pairs of linear ds DNA molecules, rare earth cations cause local (nanoscale) changes in the secondary structure of these molecules, which are analogous to the known B→Z transition (91,92).…”

Section: Second Approach: the Induction Of Interaction Between The Dsmentioning

confidence: 99%

“…Indeed, in the presence of a large excess of gadolinium ions, these ions, displacing sodium ions, are bonded to the phosphate groups of the ds DNAs. It is worth noting that, when Gd 3+ ions are bonded to polyphosphates, poorly soluble Gd-polyphosphate is formed (solubility constant is equal to about 10 −12 M) (87)(88)(89)(90)98).…”

Section: Second Approach: the Induction Of Interaction Between The Dsmentioning

confidence: 99%

From particles of liquid-crystalline dispersions to rigid deoxyribonucleic acid nanoconstructions

Yevdokimov

2011

Liquid Crystals Today

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Two theoretically feasible strategies to designing the deoxyribonucleic acid (DNA) nanoconstructions are outlined. The main data on the physico-chemical properties of liquid-crystalline dispersions formed by double-stranded nucleic acid (DNA and ribonucleic acid) molecules as a result of their phase exclusion from water-salt solutions are presented and the specific features of these molecules in quasinematic layers of the liquid-crystalline particles are allocated. The basic data obtained in this field have been used as the background for the creation of the DNA nanoconstructions carrying various 'guest' molecules (biologically active compounds or chemical substances). The unique properties of these nanoconstructions determine the possibility of manipulation with these objects, as well as the areas of their practical application.

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Synthesis and characterization of gadolinium phosphate neutron absorber

Cited by 38 publications

References 6 publications

Synchrotron X-ray analyses demonstrate phosphate-bound gadolinium in skin in nephrogenic systemic fibrosis

Synchrotron X-ray analyses demonstrate phosphate-bound gadolinium in skin in nephrogenic systemic fibrosis

Nano Imaging Technologies: Polymer vesicles loaded with precipitated gadolinium nanoparticles: A novel target-specific contrast agent for magnetic resonance imaging

From particles of liquid-crystalline dispersions to rigid deoxyribonucleic acid nanoconstructions

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