title: Fluorescent magnetic Fe3 O4 /rare Earth colloidal nanoparticles for dual-modality imaging.
abstract: Fluorescent magnetic colloidal nanoparticles (FMCNPs) are produced by a two-step, seed emulsifier-free emulsion polymerization in the presence of oleic acid and sodium undecylenate-modified Fe3 O4 nanoparticles (NPs). The Fe3 O4 /poly(St-co-GMA) nanoparticles are first synthesized as the seed and Eu(AA)3 Phen is copolymerized with the remaining St and GMA to form the fluorescent polymer shell in the second step. The uniform core-shell structured FMCNPs with a mean diameter of 120 nm exhibit superparamagnetism with saturation magnetization of 1.92 emu/g. Red luminescence from the FMCNPs is confirmed by the salient fluorescence emission peaks of europium ions at 594 and 619 nm as well as 2-photon confocal scanning laser microscopy. The in vitro cytotoxicity test conducted using the MTT assay shows good cytocompatibility and the T2 relaxivity of the FMCNPs is 353.86 mM(-1) S(-1) suggesting its potential in magnetic resonance imaging (MRI). In vivo MRI studies based on a rat model show significantly enhanced T2 -weighted images of the liver after administration and prussian blue staining of the liver tissue slice reveals accumulation of FMCNPs in the organ. The cytocompatibility, superparamagnetism, and excellent fluorescent properties of FMCNPs make them suitable for biological imaging probes in MRI and optical imaging.
authors: Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062, China.
authors: Haie
authors: H
authors: Zhu
authors: Yalei
authors: Y
authors: Shang
authors: Wenhao
authors: W
authors: Wang
authors: Yingjie
authors: Y
authors: Zhou
authors: Penghui
authors: P
authors: Li
authors: Kai
authors: K
authors: Yan
authors: Shuilin
authors: S
authors: Wu
authors: Kelvin W K
authors: KW
authors: Yeung
authors: Zushun
authors: Z
authors: Xu
authors: Haibo
authors: H
authors: Xu
authors: Paul K
authors: PK
authors: Chu
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D005290:Ferric Compounds / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005290:Ferric Compounds
keywords: colloidal nanoparticles; fluorescence imaging; magnetic resonance imaging; polymerization; rare earth complexes