Synthesis and characterisation of Gd2O3 nanocrystals functionalised by organic acids

Söderlind, Fredrik; Pedersen, Henrik; Petoral, Rodrigo; Käll, Per-Olov; Uvdal, Kajsa

doi:10.1016/j.jcis.2005.02.089

Cited by 237 publications

(245 citation statements)

References 26 publications

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“…The stretch at 1590 cm −1 is due to -COOH conjugated to a nanoparticle whereas that at 1720 cm −1 is due to free, i.e., unconjugated -COOH. Red shift by ∼130 cm −1 in conjugated -COOH had been also observed in various metal oxide nanoparticles, [21][22][23][24] supporting our result. The weight percents of surface coated PEG diacid were estimated to be 53 and 66% for samples 1 and 2, respectively, from TGA curves as shown in Figure 4.…”

Section: B Surface Coatingsupporting

confidence: 90%

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Choi

Baek

et al. 2013

AIP Advances

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Two samples of ultra small Gd(III) doped iron oxide nanoparticles were prepared to investigate Gd(III) doping effect on longitudinal (r1) and transverse (r2) water proton relaxivities. Gd(III) doping mole percents were 0.2 and 0.4 for samples 1 and 2, respectively. Average particle diameters were 2.5 to 2.1 nm for samples 1 and 2, respectively. Reduced r1 and r2 values were observed in both samples. We attributed this to reduced magnetizations arising from opposing effect of Gd(III) to net magnetizations of Fe(III)/Fe(II) in oxide nanoparticles

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Section: B Surface Coatingsupporting

confidence: 90%

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Choi

Baek

et al. 2013

AIP Advances

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“…colloidal and combustion methods [9,10], Chang et al [11] reported on the preparation of a mesoporous Gd 2 O 3 network with a tubular nanostructure by using a combination of soft template and sol-gel methods. In general, liquid based synthesis methods usually require careful control of reaction parameters such as pH, temperature, and concentration of reactants in order to obtain the desired particle size and morphology.…”

Section: Introductionmentioning

confidence: 99%

Growth of Gd2O3 nanoparticles inside mesoporous silica frameworks

Ballem

Söderlind

Nordblad

et al. 2013

Microporous and Mesoporous Materials

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Gadolinium oxide (Gd 2 O 3 ) nanoparticles with very small size and narrow size distribution were synthesized by infiltration of Gd(NO 3 ) 3 ·6H 2 O as an oxide precursor into the pores of SBA-15 mesoporous silica using a wet-impregnation technique. High resolution transmission electron microscopy and X-ray diffraction show that during the hydrothermal treatment of the precursor at 550 °C, gadolinium oxide nanoparticles inside the silica pores are formed. Subsequent dissolution of the silica framework in aqueous NaOH resulted in well dispersed nanoparticles with an average diameter of 3.6 ± 0.9 nm. If GdCl 3 ·6H 2 O is used as precursor, GdOCl is formed instead of Gd 2 O 3 . The Gd 2 O 3 nanoparticles showed a weak antiferromagnetic behaviour, as expected.

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“…Recent improvements in chemical reduction nanoparticle synthesis have led to the establishment of reliable methods for synthesizing Gd 2 O 3 nanoparticles of very fine and narrow size distributions [21,22]. We recently reported on the characterization of a new contrast agent made of ultrasmall gadolinia cores (US-Gd 2 O 3 ) capped with diethylene glycol (DEG) [23] and providing enhanced proton relaxivities compared with Gd-DTPA.…”

Section: Introductionmentioning

confidence: 99%

Polyethylene glycol-covered ultra-small Gd₂O₃nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning

et al. 2007

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The size distribution and magnetic properties of ultra-small gadolinium oxide crystals (US-Gd 2 O 3 ) were studied, and the impact of polyethylene glycol capping on the relaxivity constants (r 1 , r 2 ) and signal intensity with this contrast agent was investigated. Size distribution and magnetic properties of US-Gd 2 O 3 nanocrystals were measured with a TEM and PPMS magnetometer. For relaxation studies, diethylene glycol (DEG)-capped US-Gd 2 O 3 nanocrystals were reacted with PEG-silane (MW 5000). Suspensions were adequately dialyzed in water to eliminate traces of Gd 3+ and surfactants. The particle hydrodynamic radius was measured with dynamic light scattering (DLS) and the proton relaxation times were measured with a 1.5 T MRI scanner. Parallel studies were performed with DEG-Gd 2 O 3 and PEG-silane-SPGO (Gd 2 O 3 , < 40 nm diameter). The small and narrow size distribution of US-Gd 2 O 3 was confirmed with TEM (∼3nm)andDLS.PEG-silane-US-Gd 2 O 3 relaxation parameters were twice as high as for Gd-DTPA and the r 2 /r 1 ratio was 1.4. PEG-silane-SPGO gave low r 1 relaxivities and high r 2 /r 1 ratios, less compatible with positive contrast agent requirements. Higher r 1 were obtained with PEG-silane in comparison to DEG-Gd 2 O 3 . Treatment of DEG-US-Gd 2 O 3 with PEG-silane provides enhanced relaxivity while preventing aggregation of the oxide cores. This study confirms that PEG-covered Gd 2 O 3 nanoparticles can be used for positively contrasted MR applications requiring stability, biocompatible coatings and nanocrystal functionalization.

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Synthesis and characterisation of Gd2O3 nanocrystals functionalised by organic acids

Cited by 237 publications

References 26 publications

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Growth of Gd2O3 nanoparticles inside mesoporous silica frameworks

Polyethylene glycol-covered ultra-small Gd₂O₃nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning

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Synthesis and characterisation of Gd2O3 nanocrystals functionalised by organic acids

Cited by 237 publications

References 26 publications

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

Growth of Gd2O3 nanoparticles inside mesoporous silica frameworks

Polyethylene glycol-covered ultra-small Gd2O3nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning

Contact Info

Product

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Polyethylene glycol-covered ultra-small Gd₂O₃nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning