title: Ultrasmall near-infrared non-cadmium quantum dots for in vivo tumor imaging.
abstract: The high tumor uptake of ultrasmall near-infrared quantum dots (QDs) attributed to the enhanced permeability and retention effect is reported. InAs/InP/ZnSe QDs coated by mercaptopropionic acid (MPA) exhibit an emission wavelength of about 800 nm (QD800-MPA) with very small hydrodynamic diameter (<10 nm). Using 22B and LS174T tumor xenograft models, in vivo and ex vivo imaging studies show that QD800-MPA is highly accumulated in the tumor area, which is very promising for tumor detection in living mice. The ex vivo elemental analysis (Indium) using inductively coupled plasma (ICP) spectrometry confirm the tumor uptake of QDs. The ICP data are consistent with the in vivo and ex vivo fluorescence imaging. Human serum albumin (HSA)-coated QD800-MPA nanoparticles (QD800-MPA-HSA) show reduced localization in mononuclear phagocytic system-related organs over QD800-MPA plausibly due to the low uptake of QD800-MPA-HSA in macrophage cells. QD800-MPA-HSA may have great potential for in vivo fluorescence imaging.
authors.affiliation: Molecular Imaging Program at Stanford, Department of Radiology and Bio-X Program, School of Medicine, Stanford University, Stanford, CA 94305-5484, USA. gaojh@stanford.edu
authors.forename: Jinhao
authors.initials: J
authors.lastname: Gao
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Renguo
authors.initials: R
authors.lastname: Xie
authors.forename: Jin
authors.initials: J
authors.lastname: Xie
authors.forename: Seulki
authors.initials: S
authors.lastname: Lee
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cheng
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Peng
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D000818:Animals; D002104:Cadmium / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006801:Humans; D037102:Lectins / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry*; D009369:Neoplasms / Q000473:pathology*; D009928:Organ Specificity; D045663:Quantum Dots; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D037102:Lectins; D002104:Cadmium; D015097:3-Mercaptopropionic Acid; D016650:Fluorescein-5-isothiocyanate