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

Abstract EN

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.