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

• Published in: Contrast media and molecular imaging 2017-01, Vol.2017 (2017), p.1-10
• Main Authors: Lan, Xiaoli, Liu, Qingyao, Hu, Fan, Xia, Xiaotian, Yin, Lianglan, Zhang, Yongxue, Zhang, Yingying, Qin, Chunxia
• Format: Article
• Language: English
• Subjects: Angiogenesis; Animals; Autoradiography; Biocompatibility; Biomedical materials; Cancer; Chemical bonds; Chemical reactions; Chromatography; Computed tomography; Coupling (molecular); Cytotoxicity; Drug Delivery Systems; Endocytosis; Feasibility studies; Female; Glass substrates; Gold; Gold - chemistry; Gold - pharmacology; Humans; I.R. radiation; Imaging; Iodine; Iodine 131; Iodine isotopes; Iodine radioisotopes; Iodine Radioisotopes - chemistry; Iodine Radioisotopes - pharmacology; Ligands; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Nanorods; Nanotubes - chemistry; Neoplasms, Experimental - diagnostic imaging; Peptides; Peptides, Cyclic - chemistry; Peptides, Cyclic - pharmacology; Permeability; Photothermal conversion; Polyethylene glycol; Polyethylene Glycols - chemistry; Polyethylene Glycols - pharmacology; Single photon emission computed tomography; Single Photon Emission Computed Tomography Computed Tomography - methods; Tumor cells; Tumors
• ISSN: 1555-4309; 1555-4317
• DOI: 10.1155/2017/6081724

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 αvβ3-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 [131I]GNR-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 αvβ3-receptor-mediated endocytosis. In vivo imaging, biodistribution, and autoradiography results showed evident tumor uptake in integrin αvβ3-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.