Cellular MR Imaging

Abstract

Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall) superparamagnetic iron oxide [(U)SPIO] particles or (polymeric) paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+-chelates have mainly been used for targeted hepatobiliary imaging, and (U)SPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magnetopharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune) cell trafficking and of novel guided (stem) cell-based therapies aimed to be translated to the clinic in the future.

PET/MRI and the revolution of the third eye

“…Ultrasmall (20-40 nm) SPIO (USPIO) primarily accumulate in the lymph nodes and bone marrow, and are useful in identifying metastatic lymph nodes. Such particles may be applied to track stem cells transplanted into organs or to demonstrate macrophage activity within atherosclerotic plaque [9], and are also a suitable tool to label molecular probes targeting specific tumour-associated markers. Recently, arginine-glycine-aspartic acid USPIO (RGD-USPIO) have been used for in vivo imaging of angiogenesis in xenografts.…”

Migration, fate and in vivo imaging of adult stem cells in the CNS

“…Several techniques for in vivo cellular imaging are now available that allow the characterization of transplanted cells in the living organism, including magnetic resonance imaging (MRI), 23 bioluminescence, 24 positron emission tomography 25 and multiple photon microscopy. 26 All of these imaging methods, based on different principles, provide distinctive, usually complementary information.…”

Cationic Gd-DTPA Liposomes for Highly Efficient Labeling of Mesenchymal Stem Cells and Cell Tracking with MRI

“…by which stem cell therapy results in therapeutic benefit This has led to a vast amount of studies using a variety been hardly addressed so far. In this study these issues were addressed using bone marrow-derived mesenchyof iron oxide particles and labeling procedures (6,11,21,35,37,46,49,51,52,58,60,61). These studies showed that for mal stem cells.…”