title: Upconverting rare-earth nanoparticles with a paramagnetic lanthanide complex shell for upconversion fluorescent and magnetic resonance dual-modality imaging.
abstract: Multi-modal imaging based on multifunctional nanoparticles is a promising alternative approach to improve the sensitivity of early cancer diagnosis. In this study, highly upconverting fluorescence and strong relaxivity rare-earth nanoparticles coated with paramagnetic lanthanide complex shells and polyethylene glycol (PEGylated UCNPs@DTPA-Gd(3+)) are synthesized as dual-modality imaging contrast agents (CAs) for upconverting fluorescent and magnetic resonance dual-modality imaging. PEGylated UCNPs@DTPA-Gd(3+) with sizes in the range of 32-86 nm are colloidally stable. They exhibit higher longitudinal relaxivity and transverse relaxivity in water (r1 and r2 values are 7.4 and 27.8 s(-1) per mM Gd(3+), respectively) than does commercial Gd-DTPA (r1 and r2 values of 3.7 and 4.6 s(-1) per mM Gd(3+), respectively). They are found to be biocompatible. In vitro cancer cell imaging shows good imaging contrast of PEGylated UCNPs@DTPA-Gd(3+). In vivo upconversion fluorescent imaging and T1-weighted MRI show excellent enhancement of both fluorescent and MR signals in the livers of mice administered PEGylated UCNPs@DTPA-Gd(3+). All the experimental results indicate that the synthesized PEGylated UCNPs@DTPA-Gd(3+) present great potential for biomedical upconversion of fluorescent and magnetic resonance dual-modality imaging applications.
authors.affiliation: Department of Medical Oncology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Ji
authors.forename: Bingbo
authors.initials: B
authors.lastname: Zhang
authors.forename: Peihao
authors.initials: P
authors.lastname: Yin
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Qiu
authors.forename: Daqian
authors.initials: D
authors.lastname: Song
authors.forename: Juying
authors.initials: J
authors.lastname: Zhou
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry; D019786:Gadolinium DTPA / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009369:Neoplasms / Q000175:diagnosis*; D061848:Optical Imaging / Q000379:methods*; D011092:Polyethylene Glycols / Q000737:chemistry
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes; D028581:Lanthanoid Series Elements; D011092:Polyethylene Glycols; D019786:Gadolinium DTPA