A Synergistically Enhanced T 1 and T₂-Weighted Magnetic Resonance/Near-Infrared Contrast Agent of Gd-Doping Fe₃O₄@Fluorescence PEGylated Nanoparticles for Multimodality Imaging of Hepatocarcinoma.

In recent years, multimodal imaging nanoprobes with high resolution and high sensitivity capabilities have attracted considerable interest because they could offer complementary diagnostic information that would lead to a more precise diagnosis. Herein, the facile fabrication of Gd-doping magnetic nanoparticles conjugated with the PEGylated fluorescence probe Cy5.5 and the tumor-penetrating peptide RGERPPR (R) has been demonstrated for tri-modality targeted T1 and T₂-weighted magnetic resonance (MR) and the near-infrared (NIR) fluorescence imaging of hepatocarcinoma-bearing mice. The obtained R-GdMFs nanoparticles with a rational design are water-dispersible, have long-term stability, and have controllable magnetic delivery and excellent biocompatibility with no impact on the cell and major organ functions, as was confirmed by MTT and LDH assay, ROS measurements and H&E staining. Relaxivity measurements show a better T1 relaxivity ( r 1 ) of 16.49 mM-1 s-1 and a T₂ relaxivity ( r ₂) of 141.98 mM-1 s-1 by mutual enhancement, which realized enhanced T1 and T₂-weighted in vitro and in vivo MR imaging, which accumulated in the tumor region due to the mediation of the tumor-penetrating peptide. Meanwhile, the in vivo NIR fluorescence imaging results also revealed that the R-GdMFs could be significantly targeting the tumor tissue with bright NIR fluorescence imaging, which would lead to a more precise diagnosis. These findings indicated that as-synthesized R-GdMFs nanoparticles could be used as a platform for synergistically enhanced T1 and T₂-weighted MR/NIR fluorescence multimodality imaging in various biomedical systems.