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Initial in vitro and in vivo assessment of Au@DTDTPA-RGD nanoparticles for Gd-MRI and 68Ga-PET dual modality imaging

  • Charalmpos Tsoukalas1,
  • Gautier Laurent2,
  • Gloria Jiménez Sánchez2,
  • Theodoros Tsotakos1,
  • Rana Bazzi2,
  • Dimitris Stellas3,
  • Constantinos Anagnostopoulos3,
  • Lia Moulopoulos4,
  • Vasilis Koutoulidis4,
  • Maria Paravatou-Petsotas1,
  • Stavros Xanthopoulos1,
  • Stephane Roux2 and
  • Penelope Bouziotis1
EJNMMI Physics20152(Suppl 1):A89

Published: 18 May 2015


Radiochemical PurityBiodistribution StudyRadiochemical YieldCell BindingDual Modality

Gadolinium chelate coated gold nanoparticles (Au@DTDTPA) can be applied as contrast agents for both in vivo X-ray and magnetic resonance imaging. In this work, our aim was to radiolabel and evaluate this gold nanoparticle with Ga-68, in order to produce a dual modality PET/MRI imaging probe. For a typical preparation of 68Ga-labeled nanoparticles, the Au@DTDTPA nanoparticles (Au@DTDTPA/Au@DTDTPA-RGD) were mixed with ammonium acetate buffer, pH 5 and 40 MBq of 68Ga eluate. The mixture was then incubated for 45 min at 65 ÅãC. Radiochemical purity was determined by ITLC. In vitro stability of both radiolabeled species was assessed in saline and serum. In vitro cell binding experiments were performed on integrin ανβ3 receptor-positive U87MG cancer cells. Non-specific Au@DTDTPA was used for comparison. Ex vivo biodistribution studies and in vivo PET and MRI imaging studies in U87MG tumor-bearing SCID mice followed. The Au@DTDTPA nanoparticles were labeled with Gallium-68 at high radiochemical yield (>95%) and were stable at RT, and in the presence of serum, for up to 3 h. The cell binding assay on U87MG glioma cells proved that 68Ga-cRGD-Au@DTDTPA had specific recognition for these cells. Biodistribution studies in U87MG tumor-bearing SCID mice showed that the tumor to muscle ratio increased from 1 to 2 h p.i. (3,71 ± 0.22 and 4,69 ± 0.09 respectively), showing a clear differentiation between the affected and the non-affected tissue. The acquired PET and MRI images were in accordance to the ex vivo biodistribution results. The preliminary results of this study warrant the need for further development of Au@DTDTPA nanoparticles radiolabeled with Ga-68, as possible dual-modality PET/MRI imaging agents.

Authors’ Affiliations

National Center for Scientific Research "Demokritos", Greece
Université de Franche-Comté, Institut UTINAM, France
Biomedical Research Foundation, Academy of Athens, Greece
Department of Radiology, Areteion Hospital, University of Athens Medical School, Greece


© Tsoukalas et al; licensee Springer. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.