title: Nanoshell magnetic resonance imaging contrast agents.
abstract: Nanocontrast agents have great potential in magnetic resonance (MR) molecular imaging applications for clinical diagnosis. We synthesized Au(3)Cu(1) (gold and copper) nanoshells that showed a promising MR contrast effect. For in vitro MR images, the large proton r1 relaxivities brightened T(1)-weighted images. As for the proton-dephasing effect in T(2), Au(3)Cu(1) lightened MR images at the low concentration of 0.125 mg mL(-1) (3.84 x 10(-7) mM), and then the signal continuously decreased as the concentration increased. For in vivo MR imaging, Au(3)Cu(1) nanocontrast agents enhanced the contrast of blood vessels and suggested their potential use in MR angiography as blood-pool agents. We propose that (1) the cooperativity originating from the form of the nanoparticles and (2) the large surface area coordinated to water from their porous hollow morphology are important for efficient relaxivity. In a cytotoxicity and animal survival assay, Au(3)Cu(1) nanocontrast agents showed a dose-dependent toxic effect: the viability rate of experimental mice reached 83% at a dose of 20 mg kg(-1) and as much as 100% at 2 mg kg(-1).
authors.affiliation: Department of Chemistry and Center for Micro/Nano Science and Technology and Institute of Oral Medicine and Molecular Medicine, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Chia-Hao
authors.initials: CH
authors.lastname: Su
authors.forename: Hwo-Shuenn
authors.initials: HS
authors.lastname: Sheu
authors.forename: Chia-Yun
authors.initials: CY
authors.lastname: Lin
authors.forename: Chih-Chia
authors.initials: CC
authors.lastname: Huang
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Lo
authors.forename: Ying-Chih
authors.initials: YC
authors.lastname: Pu
authors.forename: Jun-Cheng
authors.initials: JC
authors.lastname: Weng
authors.forename: Dar-Bin
authors.initials: DB
authors.lastname: Shieh
authors.forename: Jyh-Horng
authors.initials: JH
authors.lastname: Chen
authors.forename: Chen-Sheng
authors.initials: CS
authors.lastname: Yeh
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D003287:Contrast Media; D006046:Gold; D003300:Copper