Dual-Mode Fluorescence and Magnetic Resonance Imaging by Perylene Diimide-Based Gd-Containing Magnetic Ionic Liquids

Abstract

Bioimaging plays a key role in the diagnosis/treatment of diseases and in scientific research studies. Compared with single imaging techniques, dual-mode and multimode imaging techniques facilitate high accuracy. In this work, a perylene diimide (PDI)-based Gd-containing magnetic ionic liquid, Per-6-Diimi­[Gd­(NO3)4], is reported for dual-modal imaging, in which a Gd­(III) complex was used for magnetic resonance imaging (MRI), while PDI was used for fluorescence imaging. Because of the difference in the biological microenvironment, there is a switch between dispersed and aggregated states of Per-6-Diimi­[Gd­(NO3)4] molecules in hydrophobic and hydrophilic media. When it was in the aqueous solution, the intensive π–π interaction of PDI cores made Per-6-Diimi­[Gd­(NO3)4] aggregates to form particles. The paramagnetic nanoparticles ensure prolonging the rotational correlation time, which results in a strong enhancement of MRI with a longitude relaxation coefficient of 14.94 mM–1 s–1. In an in vivo MRI experiment, the tumor site is imaged by MRI through the enhanced permeability and retention effect. However, when the molecule is present on the hydrophobic membrane of the cells, the dispersed Per-6-Diimi­[Gd­(NO3)4] showed good fluorescence imaging capabilities due to the high fluorescence quantum yield of PDI. Thus, the fluorescence imaging of cells can be carried out. Moreover, ex vivo fluorescence imaging of organs is performed after MRI. Per-6-Diimi­[Gd­(NO3)4] is enriched in the liver, kidneys, and tumors.

Multifunctional PD-L1 Targeted Fe3O4@DOX Nanoparticles Under MRI Monitoring For Combination Therapy of Triple-Negative Breast Cancer

“…Our results revealed a relatively lower signal for FPD in the tumor regions compared to Fe 3 O 4 , indicating that FPD can speci cally target the 4T1 tumors and accumulate at the tumor site for a longer time than the non-targeted Fe 3 O 4 control. For MRI, the Fe chelates are still commonly used as the agents for tumor diagnosis [38,39]. In contrast, FPD signi cantly enhanced the e cacy of nanoparticles as MRI contrast agents.…”

Ionic liquids revolutionizing biomedicine: recent advances and emerging opportunities

“…The switching characteristic between the dispersed and aggregated formation, depending on changes in the physiological environment, makes this magnetic IL suitable for dual-mode imaging through fluorescence imaging and MRI. 256 The structural tunability of ILs creates many possibilities for composition. ILs can be used as element donors and luminescence factors in imaging diagnosis, suggesting abundant applications in the diagnosis of disease influence.…”

“…The switching characteristic between the dispersed and aggregated formation, depending on changes in the physiological environment, makes this magnetic IL suitable for dual-mode imaging through fluorescence imaging and MRI. 256…”

Pyrene-Enhanced Ferromagnetic Interaction in a FeCl4–-Based Poly(ionic liquid)s Organic Magnet

“…It is prospected that stronger π–π stacking interaction further shortens the intermolecular distance, and the magnetic performance is enhanced to show phase transition from paramagnetism to ferromagnetism . As reported, pyrene, which is a kind of polycyclic aromatic hydrocarbon with a planar structure, shows a strong π–π stacking interaction. − By introducing pyrene into the MIL and PMIL, it is expected that the ferromagnetic interaction is further enhanced to show ferromagnetism.…”