Abstract
Magnetic resonance imaging(MRI)is a non-invasive medical imaging technique that has been widely applied in the clinical diagnosis of diseases across various fields.Currently,there is a dearth of high-performance dual-mode contrast agents that provide precise diagnostic information for complex diseases.In this study,iron oxide-gadolinium nanoparticles(IO-Gd NPs)bridged by hydrophilic ligand ethylenedi-amine tetramethylenephosphonic acid(EDTMP)are designed inspired by Solomon-Bloembergen-Morgan(SBM)theory,where T1 and T2 relaxivity increase with a reduction in Gd content.In particular,the NPs with minimum Gd content exhibit excellent dual-mode contrast performance(r1=94.42 mM-1 s-1,r2=343.62 mM-1 s-1).The underlying mechanism is that the bridged EDTMP coordinate limits Gd tum-bling and forces Gd3+to expose itself to the surface of the NPs.This provides more opportunities for water molecules to coordinate with Gd3+and significantly enhances proton relaxivity.Moreover,the hy-drophilicity of the ligand enhances the water dispersion stability of the NPs and increases the exchange rate of water protons near the NPs,further enhancing the dual-mode contrast effect.Finally,the biocom-patibility and in vitro/vivo imaging performances of the IO@EDTMP-Gd NPs are systematically evaluated,and the results demonstrate their potential as dual-mode contrast agents.This study provides a new strategy for developing dual-mode MRI contrast agents that can further improve the accuracy of MRI in the diagnosis of complex diseases.
基金项目
National Key R&D Program of China(2020YFA0710800)
National Key R&D Program of China(2022YFE0124500)
National Natural Science Foundation of China(32271467)
National Natural Science Foundation of China(32071364)
Outstanding Postdoctoral Program of Jiangsu Province(2022ZB367)
Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)()