Construction of ultrasmall gold nanoparticles based contrast agent via Host-Guest interaction for Tumor-targeted magnetic resonance imaging

In order to overcome the shortcomings of small-molecule contrast agents (CAs) in clinic, gadolinium-based CAs have attracted increasingly interesting in tumor diagnosis. Herein, 0-cyclodextrin-modified ultrasmall gold nanoparticle (AuNP@CD) was prepared as a functional core, which provided a large number of binding sites through host-guest interaction. Afterward, AD-PEG2000-PLL(Gd-DTPA) was anchored on the surface of AuNP@CD followed by the conjugation of folic acid through bioorthogonal chemistry, which endowed the AuNP with the capability to targeting tumor cells. Compared to Magnevist (Gd-DTPA, r(1) = 4.25 mM(-1) s(-1)) used in clinic, the AuNP nanocomposite exhibited higher longitudinal relaxivity (r(1) = 19.47 mM-(-1)s(-1)), and presented excellent biocompatibility. Furthermore, in vivo studies indicated that AuNP@CD-ADPEG2000-PLL (DTPA-Gd) nanocomposite could effectively permeate through tumor and accumulate in the tumor region, thus acquiring MR images with high resolution. These results suggest that this AuNP nanocomposite could be a potential candidate as MRI CA for tumor-targeted diagnosis. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, a 0-cyclodextrin-modified ultrasmall gold nanoparticle was prepared as a functional core, and contrast agents and folate were anchored on its surface to give it the ability to target tumor cells. Compared to clinical contrast agents, this nanocomposite exhibited higher longitudinal relaxivity and excellent biocompatibility. In vivo studies showed that it could accumulate in the tumor region and acquire high-resolution MRI images.