title: Multifunctional dendrimer-entrapped gold nanoparticles for dual mode CT/MR imaging applications.
abstract: We report the synthesis, characterization, and utilization of gadolium-loaded dendrimer-entrapped gold nanoparticles (Gd-Au DENPs) for dual mode computed tomography (CT)/magnetic resonance (MR) imaging applications. In this study, amine-terminated generation five poly(amidoamine) dendrimers (G5.NH₂) modified with gadolinium (Gd) chelator and polyethylene glycol (PEG) monomethyl ether were used as templates to synthesize gold nanoparticles (AuNPs). Followed by sequential chelation of Gd(III) and acetylation of the remaining dendrimer terminal amine groups, multifunctional Gd-Au DENPs were formed. The formed Gd-Au DENPs were characterized via different techniques. We show that the formed Gd-Au DENPs are colloidally stable and non-cytotoxic at an Au concentration up to 50 μM. With the coexistence of two radiodense imaging elements of AuNPs and Gd(III) within one NP system, the formed Gd-Au DENPs display both r₁ relaxivity for MR imaging mode and X-ray attenuation property for CT imaging mode, which enables CT/MR dual mode imaging of the heart, liver, kidney, and bladder of rat or mouse within a time frame of 45 min. Furthermore, in vivo biodistribution studies reveal that the Gd-Au DENPs have an extended blood circulation time and can be cleared from the major organs within 24 h. The strategy to use facile dendrimer technology to design dual mode contrast agents may be extended to prepare multifunctional platforms for targeted multimode molecular imaging of various biological systems.
authors.affiliation: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China.
authors.forename: Shihui
authors.initials: S
authors.lastname: Wen
authors.forename: Kangan
authors.initials: K
authors.lastname: Li
authors.forename: Hongdong
authors.initials: H
authors.lastname: Cai
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Mingwu
authors.initials: M
authors.lastname: Shen
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Huang
authors.forename: Chen
authors.initials: C
authors.lastname: Peng
authors.forename: Wenxiu
authors.initials: W
authors.lastname: Hou
authors.forename: Meifang
authors.initials: M
authors.lastname: Zhu
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zhang
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Shi
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000138:chemical synthesis; D050091:Dendrimers / Q000138:chemical synthesis*; D005260:Female; D005682:Gadolinium; D006046:Gold; D008279:Magnetic Resonance Imaging / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D053769:Nanocapsules / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D050091:Dendrimers; D053769:Nanocapsules; C104700:PAMAM Starburst; D006046:Gold; D005682:Gadolinium