title: Modification of aminosilanized superparamagnetic nanoparticles: feasibility of multimodal detection using 3T MRI, small animal PET, and fluorescence imaging.
abstract: OBJECTIVE
  The aim of our study was to modify an aminosilane-coated superparamagnetic nanoparticle for cell labeling and subsequent multimodal imaging using magnetic resonance imaging (MRI), positron emission tomography (PET), and fluorescent imaging in vivo.
  
  
  METHODS
  We covalently bound the transfection agent HIV-1 tat, the fluorescent dye fluorescein isothiocyanate, and the positron-emitting radionuclide gallium-68 to the particle and injected them intravenously into Wistar rats, followed by animal PET and MRI at 3.0 T. As a proof of principle hepatogenic HuH7 cells were labeled with the particles and observed for cell toxicity as well as detectability by MRI and biodistribution in vivo.
  
  
  RESULTS
  PET imaging and MRI revealed increasing hepatic and splenic accumulation of the particles over 24 h. Adjacent in vitro studies in hepatogenic HuH7 cells showed a rapid intracellular accumulation of the particles with high labeling efficiency and without any signs of toxicity. In vivo dissemination of the labeled cells could be followed by dynamic biodistribution studies.
  
  
  CONCLUSIONS
  We conclude that our modified superparamagnetic nanoparticles are stable under in vitro and in vivo conditions and are therefore applicable for efficient cell labeling and subsequent multimodal molecular imaging. Moreover, their multiple free amino groups suggest the possibility for further modifications and might provide interesting opportunities for various research fields.
authors: Klinik für Strahlenheilkunde, CC6, Charité Campus Virchow-Klinikum, Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. lars.stelter@charite.de
authors: Lars
authors: L
authors: Stelter
authors: Jens G
authors: JG
authors: Pinkernelle
authors: Roger
authors: R
authors: Michel
authors: Ruth
authors: R
authors: Schwartländer
authors: Nathanael
authors: N
authors: Raschzok
authors: Mehmet H
authors: MH
authors: Morgul
authors: Martin
authors: M
authors: Koch
authors: Timm
authors: T
authors: Denecke
authors: Juri
authors: J
authors: Ruf
authors: Hans
authors: H
authors: Bäumler
authors: Andreas
authors: A
authors: Jordan
authors: Bernd
authors: B
authors: Hamm
authors: Igor M
authors: IM
authors: Sauer
authors: Ulf
authors: U
authors: Teichgräber
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D005240:Feasibility Studies; D005453:Fluorescence; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008099:Liver / Q000166:cytology; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles; D049268:Positron-Emission Tomography; D051381:Rats; D017208:Rats, Wistar; D012821:Silanes / Q000378:metabolism*; D013154:Spleen / Q000166:cytology; D013194:Staining and Labeling; D014018:Tissue Distribution
chemical_list: D012821:Silanes