title: Conjugation of a water-soluble gadolinium endohedral fulleride with an antibody as a magnetic resonance imaging contrast agent.
abstract: Water-soluble gadofullerides exhibited high efficiency as magnetic resonance imaging (MRI) contrast agents. In this paper, we report the conjugation of the newly synthesized gadofulleride, Gd@C82O6(OH) 16(-)(NHCH2CH2COOH)8, with the antibody of green fluorescence protein (anti-GFP), as a model for "tumor targeted" imaging agents based on endohedral metallofullerenes. In this model system, the activity of the anti-GFP conjugate can be conveniently detected by green fluorescence protein (GFP), leading to in vitro experiments more direct and facile than those of tumor antibodies. Objective-type total internal reflection fluorescence microscopy revealed that each gadofulleride aggregate conjugated on average five anti-GFPs, and the activity of anti-GFPs was preserved after conjugation. In addition, the gadofulleride/antibody conjugate exhibited higher water proton relaxivity (12.0 mM (-1) s (-1)) than the parent gadofulleride aggregate (8.1 mM (-1) s (-1)) in phosphate buffered saline at 0.35 T, as also confirmed by T1-weighted images of phantoms. These observations clearly indicate that the synthesized gadofulleride/antibody conjugate not only has targeting potential, but also exhibits higher efficiency as an MRI contrast agent.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Shu
authors.forename: Xin-Yong
authors.initials: XY
authors.lastname: Ma
authors.forename: Jian-Fei
authors.initials: JF
authors.lastname: Zhang
authors.forename: Frank D
authors.initials: FD
authors.lastname: Corwin
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Sim
authors.forename: Er-Yun
authors.initials: EY
authors.lastname: Zhang
authors.forename: Harry C
authors.initials: HC
authors.lastname: Dorn
authors.forename: Harry W
authors.initials: HW
authors.lastname: Gibson
authors.forename: Panos P
authors.initials: PP
authors.lastname: Fatouros
authors.forename: Chun-Ru
authors.initials: CR
authors.lastname: Wang
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Fang
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003287:Contrast Media / Q000138:chemical synthesis*; D005682:Gadolinium / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000276:immunology; D007202:Indicators and Reagents; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008968:Molecular Conformation; D008970:Molecular Weight; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012995:Solubility; D013050:Spectrometry, Fluorescence; D019809:Streptavidin / Q000737:chemistry; D014867:Water
chemical_list: D000906:Antibodies; D003287:Contrast Media; D007202:Indicators and Reagents; D014867:Water; D049452:Green Fluorescent Proteins; D012710:Serum Albumin, Bovine; D001710:Biotin; D019809:Streptavidin; D005682:Gadolinium