title: Relaxometric property of organosilica nanoparticles internally functionalized with iron oxide and fluorescent dye for multimodal imaging.
abstract: Multimodal imaging using novel multifunctional nanoparticles provides a new approach for the biomedical field. Thiol-organosilica nanoparticles containing iron oxide magnetic nanoparticles (MNPs) as the core and rhodamine B in the thiol-organosilica layer (thiol OS-MNP/Rho) were synthesized in a one-pot process. The thiol OS-MNP/Rho showed enhanced magnetic resonance imaging (MRI) contrast and high fluorescence intensity. The relaxometry of thiol OS-MNP/Rho revealed a novel coating effect of the organosilica layer to the MNPs. The organosilica layer shortened the T2 relaxation time but not the T1 relaxation time of the MNPs. We injected thiol-OS-MNP/Rho into normal mice intravenously. Injected mice revealed an alteration of the liver contrast in the MRI and a fluorescent pattern based on the liver histological structure at the level between macroscopic and microscopic fluorescent imaging (mesoscopic FI). In addition, the labeled macrophages were observed at the single cell level histologically. We demonstrated a new approach to evaluate the liver at the macroscopic, microscopic level as well as the mesoscopic level using multimodal imaging.
authors.affiliation: Department of Organ Anatomy, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan. Electronic address: nakam@yamaguchi-u.ac.jp.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Division of Materials Research, Institute of Materials and Systems for Sustainability, Fro-cho, Chikusa-ku, Nagoya 464-8603, Japan. Electronic address: hayashi@imass.nagoya-u.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: Advanced Clinical Research Center, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan. Electronic address: kubo-h@fmu.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kubo
authors.affiliation: Department of Organ Anatomy, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan; Student Lab, Tokushima University Faculty Medicine, 3-18-15 Kuramoto, Tokushima 770-8503, Japan. Electronic address: taka_t_m_u@yahoo.co.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kanadani
authors.affiliation: Department of Radiology, Tokushima University Graduate School of Medical Sciences, 3-18-15 Kuramoto, Tokushima 770-8503, Japan. Electronic address: masafumi@tokushima-u.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
authors.affiliation: Division of Materials Research, Institute of Materials and Systems for Sustainability, Fro-cho, Chikusa-ku, Nagoya 464-8603, Japan. Electronic address: yogo@esi.nagoya-u.ac.jp.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Yogo
mesh_terms: D000818:Animals; D005290:Ferric Compounds / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D058185:Magnetite Nanoparticles / Q000737:chemistry; D051379:Mice; D008856:Microscopy, Fluorescence; D064847:Multimodal Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D061848:Optical Imaging / Q000379:methods*; D017646:Organosilicon Compounds / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D005456:Fluorescent Dyes; D058185:Magnetite Nanoparticles; D017646:Organosilicon Compounds; C000499:ferric oxide
keywords: Fluorescent imaging; Macrophages; Magnetic resonance imaging (MRI); Mesoscopic imaging; Multimodal imaging; Organosilica nanoparticles