title: Multimodal silica-shelled quantum dots: direct intracellular delivery, photosensitization, toxic, and microcirculation effects.
abstract: In the present study, we describe a multimodal QD probe with combined fluorescent and paramagnetic properties, based on silica-shelled single QD micelles with incorporated paramagnetic substances [tris(2,2,6,6-tetramethyl-3,5-heptanedionate)/gadolinium] into the micelle and/or silica coat. The probe was characterized with high photoluminescence quantum yield and good positive MRI contrast, low cytotoxicity, and easy intracellular delivery in viable cells. The intravenous administration of the probe in experimental animals did not affect significantly the physiological parameters and microcirculation (e.g., heart rate, blood pressure, diameter and shape of blood vessels), which makes it appropriate for tracing of blood circulation and in vivo multimodal imaging using fluorescent confocal microscopy, two-photon microscopy, and MRI.
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba 263-8555, Japan. bakalova@nirs.go.jp
authors.forename: Rumiana
authors.initials: R
authors.lastname: Bakalova
authors.forename: Zhivko
authors.initials: Z
authors.lastname: Zhelev
authors.forename: Ichio
authors.initials: I
authors.lastname: Aoki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Masamoto
authors.forename: Milka
authors.initials: M
authors.lastname: Mileva
authors.forename: Takayuki
authors.initials: T
authors.lastname: Obata
authors.forename: Makoto
authors.initials: M
authors.lastname: Higuchi
authors.forename: Veselina
authors.initials: V
authors.lastname: Gadjeva
authors.forename: Iwao
authors.initials: I
authors.lastname: Kanno
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000378:metabolism / Q000633:toxicity; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000098:blood supply* / Q000187:drug effects*; D003287:Contrast Media / Q000378:metabolism / Q000633:toxicity; D005456:Fluorescent Dyes / Q000378:metabolism / Q000633:toxicity; D005682:Gadolinium / Q000737:chemistry; D006367:HeLa Cells; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D008280:Magnetics; D008823:Micelles; D008833:Microcirculation / Q000187:drug effects; D017319:Photosensitizing Agents / Q000378:metabolism* / Q000633:toxicity; D045663:Quantum Dots; D051381:Rats; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003287:Contrast Media; D005456:Fluorescent Dyes; D008823:Micelles; D017319:Photosensitizing Agents; D012822:Silicon Dioxide; D005682:Gadolinium