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Contrast Media & Molecular Imaging
Volume 2017 (2017), Article ID 6081724, 10 pages
https://doi.org/10.1155/2017/6081724
Research Article

Synthesis and Bioevaluation of Iodine-131 Directly Labeled Cyclic RGD-PEGylated Gold Nanorods for Tumor-Targeted Imaging

1Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
2Hubei Key Laboratory of Molecular Imaging, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China

Correspondence should be addressed to Chunxia Qin and Xiaoli Lan

Received 6 September 2017; Accepted 4 December 2017; Published 24 December 2017

Academic Editor: Yuebing Wang

Copyright © 2017 Yingying Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Introduction. Radiolabeled gold nanoparticles play an important role in biomedical application. The aim of this study was to prepare iodine-131 (131I)-labeled gold nanorods (GNRs) conjugated with cyclic RGD and evaluate its biological characteristics for targeted imaging of integrin β3-expressing tumors. Methods. HS-PEG(5000)-COOH molecules were applied to replace CTAB covering the surface of bare GNRs for better biocompatibility, and c(RGDfK) peptides were conjugated onto the carboxyl terminal of GNR-PEG-COOH via EDC/NHS coupling reactions. The nanoconjugate was characterized, and 131I was directly tagged on the surface of GNRs via AuI bonds for SPECT/CT imaging. We preliminarily studied the characteristics of the probe and its feasibility for tumor-targeting SPECT/CT imaging. Results. The 131IGNR-PEG-cRGD probe was prepared in a simple and rapid manner and was stable in both PBS and fetal bovine serum. It targeted selectively and could be taken up by tumor cells mainly via integrin β3-receptor-mediated endocytosis. In vivo imaging, biodistribution, and autoradiography results showed evident tumor uptake in integrin β3-expressing tumors. Conclusions. These promising results showed that this smart nanoprobe can be used for angiogenesis-targeted SPECT/CT imaging. Furthermore, the nanoprobe possesses a remarkable capacity for highly efficient photothermal conversion in the near-infrared region, suggesting its potential as a multifunctional theranostic agent.