Silica Nanoparticles for Bimodal MRI-Optical Imaging by Grafting Gd3+and Eu3+/Tb3+Complexes

authors	Pinho, SLC; Faneca, H; Geraldes, CFGC; Rocha, J; Carlos, LD; Delville, MH
nationality	International
journal	EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
author keywords	Nanoparticles; Imaging agents; Luminescence; Bimodal imaging; MRI contrast agents
keywords	CONTRAST AGENTS; QUANTUM DOTS; GAMMA-AMINOPROPYLTRIETHOXYSILANE; INORGANIC NANOPARTICLES; LANTHANIDE COMPLEXES; LUMINESCENT PROBES; RADIO-OPAQUE; FLUORESCENT; SURFACE; EUROPIUM(III)
abstract	Bimodal magnetic resonance imaging (MRI)/optical probes for bioimaging were obtained by grafting two types of lanthanide metal ions, Gd3+ and Eu3+/Tb3+, on the surface of SiO2 nanoparticles. The resulting systems were endowed with relaxometry and photoluminescent properties, respectively. Grafting a pyridine-based aromatic backbone on to the silica surface enhances the emission quantum yield of the Eu3+-containing nanoparticles fivefold compared to similar systems that bear no aromatic antennae. The emission properties of the mixed Ln3+/Gd3+-based nanoparticles are not influenced by the presence of Gd3+. The relaxometric properties of these samples are slightly better than the properties of commercial [Gd(DTPA)]2 (DTPA = diethylenetriaminepentaacetate). When taken up by RAW 264.7 cells (mouse macrophage cell line), such bimodal probes exhibit both T1-weighted MRI increased contrast and fluorescence tracking.
publisher	WILEY-V C H VERLAG GMBH
issn	1434-1948
year published	2012
issue	16
beginning page	2828
ending page	2837
digital object identifier (doi)	10.1002/ejic.201101110
web of science category	Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000304089700031