Construction of ultrasmall gold nanoparticles based contrast agent via Host-Guest interaction for Tumor-targeted magnetic resonance imaging
Yiwei Zhang, Xinxin Li, Xing Chen, Yingfan Zhang, Yun Deng, Yanhua Yu, Bing Wang, Yanan Xue, Yulun Huang, Min Liu
Abstract
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, β-cyclodextrin-modified ultrasmall gold nanoparticle ([email protected]) 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 [email protected] 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, r1 = 4.25 mM−1 s−1) used in clinic, the AuNP nanocomposite exhibited higher longitudinal relaxivity (r1 = 19.47 mM−1 s−1), and presented excellent biocompatibility. Furthermore, in vivo studies indicated that [email protected]2000-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.