title: PEGylated dendrimer-entrapped gold nanoparticles for in vivo blood pool and tumor imaging by computed tomography.
abstract: We report the synthesis and characterization of dendrimer-entrapped gold nanoparticles (Au DENPs) modified by polyethylene glycol (PEG) with enhanced biocompatibility for computed tomography (CT) imaging applications. In this study, amine-terminated poly(amidoamine) dendrimers of generation 5 (G5.NH(2)) modified by PEG monomethyl ether (G5.NH(2)-mPEG(20)) were used as templates to synthesize Au DENPs, followed by acetylation of the remaining dendrimer terminal amines to generate PEGylated Au DENPs. The partial PEGylation modification of dendrimer terminal amines allows high loading of Au within the dendrimer interior, and consequently by simply varying the Au salt/dendrimer molar ratio, the size of the PEGylated Au DENPs can be controlled at a range of 2-4 nm with a narrow size distribution. The formed PEGylated Au DENPs are water-dispersible, stable in a pH range of 5-8 and a temperature range of 0-50 °C, and non-cytotoxic at a concentration as high as 100 μm. X-ray absorption coefficient measurements show that the attenuation intensity of the PEGylated Au DENPs is much higher than that of Omnipaque with iodine concentration similar to Au. With the sufficiently long half-decay time demonstrated by pharmacokinetics studies, the PEGylated Au DENPs enabled not only X-ray CT blood pool imaging of mice and rats after intravenous injection of the particles, but also effective CT imaging of a xenograft tumor model in nude mice. These findings suggest that the designed PEGylated Au DENPs can be used as a promising contrast agent with enhanced biocompatibility for CT imaging of various biological systems, especially in cancer diagnosis.
authors: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, People's Republic of China.
authors: Chen
authors: C
authors: Peng
authors: Linfeng
authors: L
authors: Zheng
authors: Qian
authors: Q
authors: Chen
authors: Mingwu
authors: M
authors: Shen
authors: Rui
authors: R
authors: Guo
authors: Han
authors: H
authors: Wang
authors: Xueyan
authors: X
authors: Cao
authors: Guixiang
authors: G
authors: Zhang
authors: Xiangyang
authors: X
authors: Shi
mesh_terms: D000792:Angiography / Q000379:methods; D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D005260:Female; D006046:Gold / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009369:Neoplasms / Q000000981:diagnostic imaging*; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D050091:Dendrimers; D011092:Polyethylene Glycols; D006046:Gold