title: Single (19)F probe for simultaneous detection of multiple metal ions using miCEST MRI.
abstract: The local presence and concentration of metal ions in biological systems has been extensively studied ex vivo using fluorescent dyes. However, the detection of multiple metal ions in vivo remains a major challenge. We present a magnetic resonance imaging (MRI)-based method for noninvasive detection of specific ions that may be coexisting, using the tetrafluorinated derivative of the BAPTA (TF-BAPTA) chelate as a (19)F chelate analogue of existing optical dyes. Taking advantage of the difference in the ion-specific (19)F nuclear magnetic resonance (NMR) chemical shift offset (Δω) values between the ion-bound and free TF-BAPTA, we exploited the dynamic exchange between ion-bound and free TF-BAPTA to obtain MRI contrast with multi-ion chemical exchange saturation transfer (miCEST). We demonstrate that TF-BAPTA as a prototype single (19)F probe can be used to separately visualize mixed Zn(2+) and Fe(2+) ions in a specific and simultaneous fashion, without interference from potential competitive ions.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, §Department of Biomedical Engineering, ∥Department of Chemical & Biomolecular Engineering, and ⊥Department of Oncology, The Johns Hopkins University School of Medicine , Baltimore, Maryland 21205, United States.
authors.forename: Amnon
authors.initials: A
authors.lastname: Bar-Shir
authors.forename: Nirbhay N
authors.initials: NN
authors.lastname: Yadav
authors.forename: Assaf A
authors.initials: AA
authors.lastname: Gilad
authors.forename: Peter C M
authors.initials: PC
authors.lastname: van Zijl
authors.forename: Michael T
authors.initials: MT
authors.lastname: McMahon
authors.forename: Jeff W M
authors.initials: JW
authors.lastname: Bulte
mesh_terms: D005296:Ferrous Compounds / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D066235:Fluorine-19 Magnetic Resonance Imaging; D015032:Zinc / Q000032:analysis*
chemical_list: D005296:Ferrous Compounds; D005456:Fluorescent Dyes; D015032:Zinc