title: Cell-permeable Ln(III) chelate-functionalized InP quantum dots as multimodal imaging agents.
abstract: Quantum dots (QDs) are ideal scaffolds for the development of multimodal imaging agents, but their application in clinical diagnostics is limited by the toxicity of classical CdSe QDs. A new bimodal MRI/optical nanosized contrast agent with high gadolinium payload has been prepared through direct covalent attachment of up to 80 Gd(III) chelates on fluorescent nontoxic InP/ZnS QDs. It shows a high relaxivity of 900 mM(-1) s(-1) (13 mM(-1 )s(-1) per Gd ion) at 35 MHz (0.81 T) and 298 K, while the bright luminescence of the QDs is preserved. Eu(III) and Tb(III) chelates were also successfully grafted to the InP/ZnS QDs. The absence of energy transfer between the QD and lanthanide emitting centers results in a multicolor system. Using this convenient direct grafting strategy additional targeting ligands can be included on the QD. Here a cell-penetrating peptide has been co-grafted in a one-pot reaction to afford a cell-permeable multimodal multimeric MRI contrast agent that reports cellular localization by fluorescence and provides high relaxivity and increased tissue retention with respect to commercial contrast agents.
authors: CEA-Grenoble, INAC, SCIB, Laboratoire de Reconnaissance Ionique et Chimie de Coordination, UMR-E 3 CEA-UJF, 38054 Grenoble Cedex 9, France.
authors: Graeme J
authors: GJ
authors: Stasiuk
authors: Sudarsan
authors: S
authors: Tamang
authors: Daniel
authors: D
authors: Imbert
authors: Cathy
authors: C
authors: Poillot
authors: Marco
authors: M
authors: Giardiello
authors: Céline
authors: C
authors: Tisseyre
authors: Emmanuel L
authors: EL
authors: Barbier
authors: Pascal Henry
authors: PH
authors: Fries
authors: Michel
authors: M
authors: de Waard
authors: Peter
authors: P
authors: Reiss
authors: Marinella
authors: M
authors: Mazzanti
mesh_terms: D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D002614:Chelating Agents / Q000737:chemistry*; D006224:Cricetinae; D003412:Cricetulus; D005682:Gadolinium / Q000737:chemistry; D007204:Indium / Q000737:chemistry* / Q000378:metabolism*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D057054:Molecular Imaging / Q000379:methods*; D055620:Optical Phenomena; D009942:Organometallic Compounds / Q000737:chemistry; D010539:Permeability; D010720:Phosphines / Q000737:chemistry* / Q000378:metabolism*; D045663:Quantum Dots; D051381:Rats; D013050:Spectrometry, Fluorescence; D013440:Sulfides / Q000737:chemistry; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D010720:Phosphines; D013440:Sulfides; D017967:Zinc Compounds; D007204:Indium; D005682:Gadolinium; C031238:zinc sulfide; C090882:indium phosphide