Gold Nanoparticles Coated with Gd-Chelate as a Potential CT/MRI Bimodal Contrast Agent

Abstract

The synthesis and characterization of gold nanoparticles coated by Gd-chelate (GdL@Au) is described, where L is a conjugate of DTPA (DTPA = diethylenetriamine-N,N,N',N'',N''-pentaacetic acid) and 4-aminothiophenol. These particles are obtained by the replacement of citrate from the gold nanoparticle surfaces with gadolinium chelate (GdL). The average size of GdL@Au is 12 nm with a loading of GdL reaching up to 1.4 × 10 3 per particles, and they demonstrate very high r1 relaxivity (~10 4 mM -1 s -1 ) and the r1 relaxivity per [Gd] is as high as 10 mM. Here, we also describe the use of bimodality of this contrast agent (CA) as a highly efficient CT contrast agent based on gold nanoparticles (GNPs) that overcome the limitations of iodine based contrast agent. The MTT assay performed on this CAs reveals the cytotoxicity as low as that for Omniscan ® in the concentration range required to obtain intensity enhancement in the in vivo MRI study

Biocompatible folate-modified Gd3+/Yb3+-doped ZnO nanoparticles for dualmodal MRI/CT imaging

“…One logical strategy was the combination of gadolinium chelates (Gd-DTPA or Gd-DO3A with high relaxation efficiency) with Au nanostructures (nanoparticles, nanorods, as well as nanoclusters with higher atomic number and strong X-ray attenuation property). [17][18][19][20] Moreover, Gd-DTPA modied lanthanide-based upconversion nanoparticles were also designed and prepared for MR and CT imaging. 21,22 The other strategy involved the doping of different lanthanide ions into a nanoplatform to achieve multi modal MRI/CT imaging probes.…”

Poly(acrylic acid) Bridged Gadolinium Metal–Organic Framework–Gold Nanoparticle Composites as Contrast Agents for Computed Tomography and Magnetic Resonance Bimodal Imaging

“…Moreover, it is difficult to further functionalize the small molecules for targeting or other purposes (e.g., adding another imaging agent). , AuNPs have been demonstrated to be suitable as a contrast agent for CT imaging due to their high atomic number, superior absorption coefficient, and tunable particle size and morphology. A number of studies − have reported the combination of Au nanospheres and Gd chelates for the preparation of multimodal MRI/CT contrast agents since the seminal work of Debouttière et al In addition, further studies, such as Gd-chelate-modified gold nanorods or nanospheres, − Gd-enriched DNA AuNPs conjugates, and combining Gd chelates with gold nanostructures as multimodal MRI/CT contrast agents have been conducted. However, all of these reported Gd/Au-based multimodal contrast agents for MRI/CT imaging involve Gd chelate materials.…”

Biogenic Synthesis of Gold Nanoparticles on a Green Support as a Reusable Catalyst for the Hydrogenation of Nitroarene and Quinoline

“…AuNPs are normally prepared using appropriate reducing agents, such as sodium borohydride, sodium thiocyanate, thiols, tannic acids, and ascorbic acids [44,45] . In most cases, stabilizing agents are used to prevent agglomeration and achieve a higher stability and growth.…”

“…AuNPs are normally prepared using appropriate reducing agents, such as sodium borohydride, sodium thiocyanate, thiols, tannic acids, and ascorbic acids. [44,45] In most cases, stabilizing agents are used to prevent agglomeration and achieve a higher stability and growth. However, biogenic surfaces with unique functionalities have grabbed the attention for the formation of AuNPs due to the associated green chemistry lending the process higher environmental credentials.…”