title: A nanocomposite of Au-AgI core/shell dimer as a dual-modality contrast agent for x-ray computed tomography and photoacoustic imaging.
abstract: OBJECTIVE
  To develop a core/shell nanodimer of gold (core) and silver iodine (shell) as a dual-modal contrast-enhancing agent for biomarker targeted x-ray computed tomography (CT) and photoacoustic imaging (PAI) applications.
  
  
  METHODS
  The gold and silver iodine core/shell nanodimer (Au/AgICSD) was prepared by fusing together components of gold, silver, and iodine. The physicochemical properties of Au/AgICSD were then characterized using different optical and imaging techniques (e.g., HR- transmission electron microscope, scanning transmission electron microscope, x-ray photoelectron spectroscopy, energy-dispersive x-ray spectroscopy, Z-potential, and UV-vis). The CT and PAI contrast-enhancing effects were tested and then compared with a clinically used CT contrast agent and Au nanoparticles. To confer biocompatibility and the capability for efficient biomarker targeting, the surface of the Au/AgICSD nanodimer was modified with the amphiphilic diblock polymer and then functionalized with transferrin for targeting transferrin receptor that is overexpressed in various cancer cells. Cytotoxicity of the prepared Au/AgICSD nanodimer was also tested with both normal and cancer cell lines.
  
  
  RESULTS
  The characterizations of prepared Au/AgI core/shell nanostructure confirmed the formation of Au/AgICSD nanodimers. Au/AgICSD nanodimer is stable in physiological conditions for in vivo applications. Au/AgICSD nanodimer exhibited higher contrast enhancement in both CT and PAI for dual-modality imaging. Moreover, transferrin functionalized Au/AgICSD nanodimer showed specific binding to the tumor cells that have a high level of expression of the transferrin receptor.
  
  
  CONCLUSIONS
  The developed Au/AgICSD nanodimer can be used as a potential biomarker targeted dual-modal contrast agent for both or combined CT and PAI molecular imaging.
authors.affiliation: Department of Radiology and Imaging Sciences and Center for Systems Imaging, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Anamaria
authors.initials: A
authors.lastname: Orza
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Biomedical Engineering, University of Michigan School of Medicine, Ann Arbor, Michigan 48109.
authors.forename: Ting
authors.initials: T
authors.lastname: Feng
authors.affiliation: Department of Biomedical Engineering, University of Michigan School of Medicine, Ann Arbor, Michigan 48109.
authors.forename: Xueding
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology and Imaging Sciences and Center for Systems Imaging, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Radiology and Imaging Sciences and Center for Systems Imaging, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Yuancheng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Surgery, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Lily
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Radiology and Imaging Sciences and Center for Systems Imaging, Emory University School of Medicine, Atlanta, Georgia 30322.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
mesh_terms: D003287:Contrast Media / Q000737:chemistry* / Q000633:toxicity; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007454:Iodides / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D061088:Photoacoustic Techniques / Q000379:methods*; D018030:Silver Compounds / Q000737:chemistry*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007454:Iodides; D018030:Silver Compounds; D006046:Gold; C030584:silver iodide