Guanshu Liu1,2, Matthew M. Moake3,
Assaf A. Gilad2,4, Muksit Jamil2, Yah-el Har-el2,
Chris Long3, Piotr Walczak2,4, Jiangyang Zhang2,
Amanda Cardona2, Marco A. DeLiso2, George Sgouros2,
Jeff W.M. Bulte2,4, Peter C.M. van Zijl1,2, Michael T.
McMahon1,2
1F.M. Kirby Research Center for
Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United
States; 2Department of Radiology, Johns Hopkins University School
of Medicine, Baltimore, MD, United States; 3Department of
Biomedical Engineering, Johns Hopkins University School of Medicine,
Baltimore, MD, United States; 4Institute for Cell Engineering,
Johns Hopkins University School of Medicine, Baltimore, MD, United States
We
developed a new MR-visible liposome system based on labeling with three
distinct diamagnetic Chemical Exchange Saturation Transfer (DIACEST) agents,
L-arginine, poly-L-lysine and glycogen. Using saturation frequency swept MRI
with B0-correction, the accumulation of all three types of DIACEST liposomes
in mouse popliteal lymph nodes could be visualized. As a proof of concept, we
demonstrate the first in-vivo multi-contrast (multi-color) MRI using two
DIACEST agents, L-arginine liposomes and poly-L-lysine liposomes, that were
simultaneously injected to two footpads of the same mouse. This new system
allows direct monitoring of liposomal uptake in lymph nodes without any
paramagnetic or super-paramagnetic contrast material.