Photoinduced Superhydrophilicity of Gd-Doped TiO₂ Ellipsoidal Nanoparticles Boosts T₁ Contrast Enhancement for Magnetic Resonance Imaging

Abstract

The unsatisfactory performance of current gadolinium chelate based T 1 contrast agents (CAs) for magnetic resonance imaging (MRI) stimulates the search for better alternatives. Herein, we report a new strategy to substantially improve the capacity of nanoparticle-based T 1 CAs by exploiting the photoinduced superhydrophilic assistance (PISA) effect. As a proof of concept, we synthesized citrate-coated Gd-doped TiO2 ellipsoidal nanoparticles (GdTi-SC NPs), whose r 1 increases significantly upon UV irradiation. The reduced water contact angle and the increased number of surface hydroxyl groups substantiate the existence of the PISA effect, which considerably promotes the efficiency of paramagnetic relaxation enhancement (PRE) and thus the imaging performance of GdTi-SC NPs. In vivo MRI of SD rats with GdTi-SC NPs further demonstrates that GdTi-SC NPs could serve as a high-performance CA for sensitive imaging of blood vessels and accurate diagnosis of vascular lesions, indicating the success of our strategy.

Gadolinium(III) Complex-Backboned Branched Polymers as Imaging Probes for Contrast-Enhanced Magnetic Resonance Angiography

“…The vascular stenosis model was constructed on the left lower limb of SD rats using a retaining clip. ,, After clamping for 10 min, T 1 images of the lower limb blood vessel of SD rats were acquired after intravenous injection of P4-Gd at a dose of 0.05 mmol Gd/kg BW.…”

Surface modification of TiO2 nanoparticles with organic molecules and their biological applications

“…In another research, Liu et al synthesized citrate-coated Gd-doped TiO 2 ellipsoidal nanoparticles (GdTi-SC NPs) to improve the efficiency of gadolinium-based T1 contrast agents (CAs) for magnetic resonance imaging (MRI). 124 The in vivo MRI tests on rats demonstrated that the modified TiO 2 NPs have a high potential ability as high-performance T1 contrast agents for the sensitive imaging of blood vessels and the accurate diagnosis of vascular lesions. Peper et al studied redox reactions of aqueous colloidal solutions of both citrate capped- and uncapped-TiO 2 NPs (c-TiO 2 and uc-TiO 2 ) and reported the different redox behaviors of these two systems.…”

The adjacent effect between Gd(iii) and Cu(ii) in layered double hydroxide nanoparticles synergistically enhancesT1-weighted magnetic resonance imaging contrast

“…8 Gadolinium(III) (Gd(III)) has a high magnetic moment and long electron spin relaxation time, and has become the most widely studied magnetic metal center for T 1 -MR imaging applications. [9][10][11] Other metal ion-based agents, such as manganese(II) (Mn(II)) and copper(II) (Cu(II)), are becoming promising candidates for clinical T 1 -MRI practice. [12][13][14] To improve MR imaging contrast, recent investigations have focused on embedding paramagnetic species (such as Gd(III), Mn(II), and Cu(II)) inside iron oxide (IO) nanoparticles to enable the spin of T 1 contrast species to coordinate the local magnetic field induced by the T 2 -weighted IO nanoparticles.…”