New long circulating magnetoliposomes as contrast agents for detection of ischemia-reperfusion injuries by MRI

New long circulating magnetoliposomes coated with polyethylene glycol (PEG), and loaded with PEG-coated 10nm superparamagnetic iron oxide nanoparticles (SPION), were developed. The magnetoliposomes relaxivities r₁, r₂ measured in a magnetic field of 7T showed a minor effect on T₁, but a major effect on T₂. These nanosystems were used as a negative contrast agent for MRI in a nonclinical study to visualize, in a rat model of liver ischemia, ischemia-reperfusion injuries. Magnetic resonance micro-images (MRM) at 7T were obtained for rat liver with and without magnetoliposomes administration and analyzed in comparison with liver biomarkers and histological results. These new long circulating magnetoliposomes enhanced the detection of lesions indicating their potential use as efficient MRI negative contrast agent for the detection of liver ischemia-reperfusion injuries. From the Clinical Editor: This paper describes the generation of PEGylated magnetoliposomes and demonstrates their feasibility as negative contrast agents in a liver ischemia-reperfusion rat model.