title: Highly water-dispersible surface-modified Gd(2)O(3) nanoparticles for potential dual-modal bioimaging.
abstract: Water-dispersible and luminescent gadolinium oxide (GO) nanoparticles (NPs) were designed and synthesized for potential dual-modal biological imaging. They were obtained by capping gadolinium oxide nanoparticles with a fluorescent glycol-based conjugated carboxylate (HL). The obtained nanoparticles (GO-L) show long-term colloidal stability and intense blue fluorescence. In addition, L can sensitize the luminescence of europium(III) through the so-called antenna effect. Thus, to extend the spectral ranges of emission, europium was introduced into L-modified gadolinium oxide nanoparticles. The obtained EuIII-doped particles (Eu:GO-L) can provide visible red emission, which is more intensive than that without L capping. The average diameter of the monodisperse modified oxide cores is about 4 nm. The average hydrodynamic diameter of the L-modified nanoparticles was estimated to be about 13 nm. The nanoparticles show effective longitudinal water proton relaxivity. The relaxivity values obtained for GO-L and Eu:GO-L were r1=6.4 and 6.3 s−1 mM−1 with r2/r1 ratios close to unity at 1.4 T. Longitudinal proton relaxivities of these nanoparticles are higher than those of positive contrast agents based on gadolinium complexes such as Gd-DOTA, which are commonly used for clinical magnetic resonance imaging. Moreover, these particles are suitable for cellular imaging and show good biocompatibility.
authors.forename: Zhangjun
authors.initials: Z
authors.lastname: Hu
authors.forename: Maria
authors.initials: M
authors.lastname: Ahrén
authors.forename: Linnéa
authors.initials: L
authors.lastname: Selegård
authors.forename: Caroline
authors.initials: C
authors.lastname: Skoglund
authors.forename: Fredrik
authors.initials: F
authors.lastname: Söderlind
authors.forename: Maria
authors.initials: M
authors.lastname: Engström
authors.forename: Xuanjun
authors.initials: X
authors.lastname: Zhang
authors.forename: Kajsa
authors.initials: K
authors.lastname: Uvdal
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D005063:Europium / Q000737:chemistry; D005682:Gadolinium / Q000737:chemistry*; D006367:HeLa Cells; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry; D006801:Humans; D008279:Magnetic Resonance Imaging; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D018613:Microscopy, Confocal; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D003287:Contrast Media; D006573:Heterocyclic Compounds, 1-Ring; D014867:Water; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid; D005063:Europium; C030581:gadolinium oxide; D005682:Gadolinium