| Download | - View accepted manuscript: PEG-covered ultra-small Gd₂O₃ nanoparticles for positive contrast at 1.5T MR clinical scanning (PDF, 907 KiB)
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| DOI | Resolve DOI: https://doi.org/10.1088/0957-4484/18/39/395501 |
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| Author | Search for: Fortin, Marc-André; Search for: Petoral Jr., Rodrigo M.; Search for: Söderlind, Fredrik; Search for: Klasson, A.; Search for: Engstöm, Maria; Search for: Veres, Teodor1; Search for: Käll, Per-Olod; Search for: Uvdal, Kajsa |
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| Affiliation | - National Research Council of Canada. NRC Industrial Materials Institute
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| Format | Text, Article |
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| Abstract | The size distribution and magnetic properties of ultra-small gadolinium oxide crystals (US-Gd₂O₃) were studied, and the impact of polyethylene glycol capping on the relaxivity constants (r₁, r₂) and signal intensity with this contrast agent was investigated. Size distribution and magnetic properties of US-Gd₂O₃ nanocrystals were measured with a TEM and PPMS magnetometer. For relaxation studies, diethylene glycol (DEG)-capped US-Gd₂O₃ nanocrystals were reacted with PEG-silane (MW 5000). Suspensions were adequately dialyzed in water to eliminate traces of Gd³⁺ 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–Gd₂O₃ and PEG-silane–SPGO (Gd₂O₃, < 40 nm diameter). The small and narrow size distribution of US-Gd₂O₃ was confirmed with TEM (∼3 nm) and DLS. PEG-silane–US-Gd₂O₃ relaxation parameters were twice as high as for Gd–DTPA and the r₂/r₁ ratio was 1.4. PEG-silane–SPGO gave low r₁ relaxivities and high r₂/r₁ ratios, less compatible with positive contrast agent requirements. Higher r₁ were obtained with PEG-silane in comparison to DEG–Gd₂O₃. Treatment of DEG–US-Gd₂O₃ with PEG-silane provides enhanced relaxivity while preventing aggregation of the oxide cores. This study confirms that PEG-covered Gd₂O₃ nanoparticles can be used for positively contrasted MR applications requiring stability, biocompatible coatings and nanocrystal functionalization. |
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| Publication date | 2007-09-04 |
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| Language | English |
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| Peer reviewed | Yes |
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| NRC number | NRCC 53688 |
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| NPARC number | 15859840 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | d204616c-f9e6-4780-bb1a-d767a762af42 |
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| Record created | 2010-07-23 |
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| Record modified | 2020-05-10 |
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