title: Multifunctional silica nanoparticles for optical and magnetic resonance imaging.
abstract: The surface of spherical, nonporous silica nanoparticles (SiO2-NPs) was modified with gadolinium (Gd) complexes, fluorophores, and cell-penetrating peptides to achieve multifunctionality on a single particle. The Gd surface concentrations were 9-16 μmol/g resulting in nanomaterials with high local longitudinal and transversal relaxivities (~1×10(5) and ~5×10(5) /mm/s/NP, respectively). Rapid cellular uptake was observed in vitro; however, larger extracellular agglomerates were also formed. In vivo administration revealed a fast distribution throughout the body followed by a nearly complete disappearance of fluorescence in all organs except the lungs, liver, and spleen after 24 h. Such NPs have the potential to serve as efficient multimodal probes in molecular imaging.
authors.affiliation: High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Spemannstrasse 41, D-72076 Tübingen, Germany. rajendra.joshi@tuebingen.mpg.de
authors.forename: Rajendra
authors.initials: R
authors.lastname: Joshi
authors.forename: Verena
authors.initials: V
authors.lastname: Feldmann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Koestner
authors.forename: Claudia
authors.initials: C
authors.lastname: Detje
authors.forename: Sven
authors.initials: S
authors.lastname: Gottschalk
authors.forename: Hermann A
authors.initials: HA
authors.lastname: Mayer
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sauer
authors.forename: Jörn
authors.initials: J
authors.lastname: Engelmann
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005682:Gadolinium / Q000737:chemistry / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D051379:Mice; D008807:Mice, Inbred BALB C; D057054:Molecular Imaging / Q000379:methods*; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry; D061848:Optical Imaging / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D012822:Silicon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014018:Tissue Distribution
chemical_list: D009942:Organometallic Compounds; D012822:Silicon Dioxide; D005682:Gadolinium