title: Cryptophane-folate biosensor for (129)xe NMR.
abstract: Folate-conjugated cryptophane was developed for targeting cryptophane to membrane-bound folate receptors that are overexpressed in many human cancers. The cryptophane biosensor was synthesized in 20 nonlinear steps, which included functionalization with folate recognition moiety, solubilizing peptide, and Cy3 fluorophore. Hyperpolarized (129)Xe NMR studies confirmed xenon binding to the folate-conjugated cryptophane. Cellular internalization of biosensor was monitored by confocal laser scanning microscopy and quantified by flow cytometry. Competitive blocking studies confirmed cryptophane endocytosis through a folate receptor-mediated pathway. Flow cytometry revealed 10-fold higher cellular internalization in KB cancer cells overexpressing folate receptors compared to HT-1080 cells with normal folate receptor expression. The biosensor was determined to be nontoxic in HT-1080 and KB cells by MTT assay at low micromolar concentrations typically used for hyperpolarized (129)Xe NMR experiments.
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Najat S
authors.initials: NS
authors.lastname: Khan
authors.forename: Brittany A
authors.initials: BA
authors.lastname: Riggle
authors.forename: Garry K
authors.initials: GK
authors.lastname: Seward
authors.forename: Yubin
authors.initials: Y
authors.lastname: Bai
authors.forename: Ivan J
authors.initials: IJ
authors.lastname: Dmochowski
mesh_terms: D001692:Biological Transport; D045744:Cell Line, Tumor; D005456:Fluorescent Dyes / Q000737:chemistry; D005492:Folic Acid / Q000737:chemistry*; D058972:Folic Acid Transporters / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000633:toxicity; D011083:Polycyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000633:toxicity
chemical_list: D005456:Fluorescent Dyes; D058972:Folic Acid Transporters; D015335:Molecular Probes; D011083:Polycyclic Compounds; C523242:cryptophane; D005492:Folic Acid