title: In vivo tumor-targeted fluorescence imaging using near-infrared non-cadmium quantum dots.
abstract: This article reported the high tumor targeting efficacy of RGD peptide labeled near-infrared (NIR) non-cadmium quantum dots (QDs). After using poly(ethylene glycol) to encapsulate InAs/InP/ZnSe QDs (emission maximum at about 800 nm), QD800-PEG dispersed well in PBS buffer with the hydrodynamic diameter (HD) of 15.9 nm and the circulation half-life of approximately 29 min. After coupling QD800-PEG with arginine-glycine-aspartic acid (RGD) or arginine-alanine-aspartic acid (RAD) peptides, we used nude mice bearing subcutaneous U87MG tumor as models to test tumor-targeted fluorescence imaging. The results indicated that the tumor uptake of QD800-RGD is much higher than those of QD800-PEG and QD800-RAD. The semiquantitative analysis of the region of interest (ROI) showed a high tumor uptake of 10.7 +/- 1.5%ID/g in mice injected with QD800-RGD, while the tumor uptakes of QD800-PEG and QD800-RAD were 2.9 +/- 0.3%ID/g and 4.0 +/- 0.5%ID/g, respectively, indicating the specific tumor targeting of QD800-RGD. The high reproducibility of bioconjunction between QDs and the RGD peptide and the feasibility of QD-RGD bioconjugates as tumor-targeted fluorescence probes warrant the successful application of QDs for in vivo molecular imaging.
authors.affiliation: Molecular Imaging Program at Stanford, Department of Radiology and Bio-X Program, School of Medicine, Stanford University, 1201 Welch Road, Stanford, California 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: Yongjun
authors.initials: Y
authors.lastname: Yan
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: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000175:diagnosis*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D045663:Quantum Dots
chemical_list: D005456:Fluorescent Dyes; D009842:Oligopeptides; D011092:Polyethylene Glycols; C047981:arginyl-glycyl-aspartic acid