Facile Preparation of Double Rare Earth-Doped Carbon Dots for MRI/CT/FI Multimodal Imaging

Abstract

The integration of different imaging functions into an ultrasmall nanoplatform with excellent biocompatibility and metabolic performance to fabricate multimodal imaging probes has been a tremendous challenge. Herein, a novel kind of gadolinium-and ytterbium-doped carbon dots (Gd/Yb@ CDs) with diameter of 5.26 ± 0.93 nm was obtained by the convenient one-step hydrothermal process for magnetic resonance imaging (MRI), X-ray computed tomography (CT), and fluorescent imaging (FI). The obtained Gd/Yb@ CDs exhibited not only the excitation-dependent emission and superhigh photostability but also higher longitudinal relaxivity (r 1 = 6.65 mM −1 s −1 ) and excellent X-ray absorption performance (45.43 HU L g −1 ). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, tissue section assessment, and body weight investigation shed light on the superior biocompatibility of these Gd/Yb@CDs. MRI/CT imaging demonstrated these multimodal nanoprobes could give rise to obviously enhanced contrast effect on the xenografted tumor model. Furthermore, biodistribution analysis demonstrated that these nanoprobes could be easily removed from the mice through the kidney elimination pathway. Therefore, the present Gd/Yb@CDs could be served as promising MRI/CT/FI multimodal nanoprobes to provide more accurate and comprehensive diagnosis information.

Recent advance of carbon dots in bio-related applications

“…After intravenous injection, I-doped CDs were distributed throughout the body datable by X-ray CT imaging and excreted by renal clearance. Gd/Yb@CDs were synthesized from Na 2 EDTA, GdCl 3 , YbCl 3 , and L-arginine by hydrothermal method [85]. Gd/Yb@CDs exhibited blue emission, and higher longitudinal relaxivity (r 1 = 6.65 mM −1 s −1 ) and excellent X-ray absorption performance (45.43 HU l g −1 ).…”

Organic dots (O-dots) for theranostic applications: preparation and surface engineering

“…This application is based on their photoluminescence properties, 296,297 although they can be hybridized with other particles for use in other imaging modalities. [298][299][300] Bioimaging can both provide basic knowledge about biological systems and used in diagnostic methods. Bioimaging is one of the pivots of theranostics, and since GQDs and CQDs are suitable cargo carriers and demonstrate other therapeutic activities including photothermal therapy and photodynamic therapy, showing bioimaging capabilities, they are promising theranostic agents.…”

The Renal Clearable Magnetic Resonance Imaging Contrast Agents: State of the Art and Recent Advances

“…The r1 value of Gd-CDs As a rising star of carbon nanomaterial, carbon quantum dots (CDs) have drawn tremendous attention because of their excellent optical property, high physicochemical stability, good biocompatibility, and the ease of surface functionalization [53][54][55][56][57]. Recently, various Gd 3+ -doped CDs (Gd-CD) have been synthesized for fluorescence/MR dual-mode imaging by the low temperature pyrolysis of precursors containing Gd 3+ (such as Gd 3+ -complexes) and carbon [58][59][60][61]. Zou and coauthors reported Gd-CD-based theranostics for MRI-guided radiotherapy of a tumor (as shown in Figure 5) [58].…”