title: X-ray computed tomography contrast agents prepared by seeded growth of gold nanoparticles in PEGylated dendrimer.
abstract: Gold nanoparticles (Au NPs) are a potential x-ray computed tomography (CT) contrast agent. A biocompatible and bioinactive surface is necessary for application of gold nanoparticle to CT imaging. Polyethylene glycol (PEG)-attached dendrimers have been used as a drug carrier with long blood circulation. In this study, the Au NPs were grown in the PEGylated dendrimer to produce a CT contrast agent. The Au NPs were grown by adding gold ions and ascorbic acid at various equivalents to the Au NP-encapsulated dendrimer solution. Both size and surface plasmon absorption of the grown Au NPs increased with adding a large number of gold ions. The x-ray attenuation of the Au NPs also increased after the seeded growth. The Au NPs grown in the PEG-attached dendrimer at the maximum under our conditions exhibited a similar CT value to a commercial iodine agent, iopamidol, in vitro. The Au NP-loaded PEGylated dendrimer and iopamidol were injected into mice and CT images were obtained at different times. The Au NP-loaded PEGylated dendrimer achieved a blood pool imaging, which was greater than a commercial iodine agent. Even though iopamidol was excreted rapidly, the PEGylated dendrimer loading the grown Au NP was accumulated in the liver.
authors.affiliation: Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan. c-kojima@21c.osakafu-u.ac.jp
authors.forename: Chie
authors.initials: C
authors.lastname: Kojima
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Umeda
authors.forename: Mikako
authors.initials: M
authors.lastname: Ogawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Harada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Magata
authors.forename: Kenji
authors.initials: K
authors.lastname: Kono
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000737:chemistry* / Q000493:pharmacokinetics; D050091:Dendrimers / Q000737:chemistry* / Q000493:pharmacokinetics; D006046:Gold; D008297:Male; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000493:pharmacokinetics; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D050091:Dendrimers; D011092:Polyethylene Glycols; D006046:Gold