title: Tailor-made quantum dot and iron oxide based contrast agents for in vitro and in vivo tumor imaging.
abstract: The biofunctionalization of CdSe/CdS/ZnS quantum dots and Fe(3)O(4) nanocrystals using a novel ligand system based on polyisoprene-block-poly(ethylene oxide) ligands is described. The synthesis includes a partial ligand exchange of the hydrophobic nanocrystals with amino-functionalized polyisoprene ligands, followed by seeded micelle formation of the diblock-copolymers in water. The resulting water-soluble quantum dots showed fluorescence quantum efficiencies in the 40 to 50% range and extraordinary fluorescence stability in the biological environment after cross-linking of the polyisoprene moiety of the ligand shell. No toxicity was detected by water-soluble tetrazolium (WST8) and lactate dehydrogenase (LDH) assays, even at very high nanoparticle concentrations, and almost no nonspecific cell adhesion was detected. The ligand shell was further coupled to the antigen-related cell adhesion molecule (CEACAM) specific monoclonal antibody T84.1. The so-conjugated Fe(3)O(4) nanocrystals allowed in vitro and in vivo tumor targeting by magnetic resonance imaging.
authors.affiliation: Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany. elmar.poeselt@chemie.uni-hamburg.de
authors.forename: Elmar
authors.initials: E
authors.lastname: Pöselt
authors.forename: Christian
authors.initials: C
authors.lastname: Schmidtke
authors.forename: Steffen
authors.initials: S
authors.lastname: Fischer
authors.forename: Kersten
authors.initials: K
authors.lastname: Peldschus
authors.forename: Johannes
authors.initials: J
authors.lastname: Salamon
authors.forename: Hauke
authors.initials: H
authors.lastname: Kloust
authors.forename: Huong
authors.initials: H
authors.lastname: Tran
authors.forename: Andrea
authors.initials: A
authors.lastname: Pietsch
authors.forename: Markus
authors.initials: M
authors.lastname: Heine
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Udo
authors.initials: U
authors.lastname: Schumacher
authors.forename: Christoph
authors.initials: C
authors.lastname: Wagener
authors.forename: Stephan
authors.initials: S
authors.lastname: Förster
authors.forename: Horst
authors.initials: H
authors.lastname: Weller
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002471:Cell Transformation, Neoplastic; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D003287:Contrast Media / Q000737:chemistry*; D005027:Ethylene Oxide / Q000031:analogs & derivatives / Q000737:chemistry; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry*; D015972:Gene Expression Regulation, Neoplastic; D019073:HT29 Cells; D045782:Hemiterpenes / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D045663:Quantum Dots; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D015815:Cell Adhesion Molecules; D003287:Contrast Media; D005290:Ferric Compounds; D045782:Hemiterpenes; C543622:poly(isoprene-block-ethylene oxide); D014867:Water; C000499:ferric oxide; D005027:Ethylene Oxide