February 26, 2007
Perfluorocarbon Nanoparticles Track Living Cells
Stem cell therapy, primarily bone marrow transplantation, plays a key role in treating leukemia and other types of cancer. To better track the fate of stem cells injected into patients, researchers at the Siteman Center of Cancer Nanotechnology Excellence (CCNE) have turned to a combination of fluorine-based magnetic resonance imaging (MRI) and nanoparticles made of liquid perfluorocarbons.
Reporting its work in The FASEB Journal, a team of investigators led by Samuel Wickline, M.D., principal investigator of the Siteman CCNE, and long-time collaborator Gregory Lanza, M.D., both at Washington University in St. Louis, described its use of two distinct perfluorocarbon nanoparticles to track different stem cells injected into tumor-bearing mice. These particular nanoparticles are taken up readily by stem cells over the course of a 12-hour incubation, and the stem cells showed no ill effects from the nanoparticles.
Using 19F MRI, the researchers showed that they could detect as few as 6,000 labeled stem cells in animals. With 19F MR spectroscopy, a similar but more sensitive technique, the investigators could detect 2,000 labeled cells. This series of experiments showed clearly the benefits of using 19F MRI, as opposed to standard 1H-MRI. With little fluorine existing naturally in the body, there was little background noise in the MRI scans, which had the effect of boosting the ability to detect labeled cells in the body.
This work, which was supported by the National Cancer Institute’s Alliance for Nanotechnology in Cancer, is detailed in a paper titled, “19F magnetic resonance imaging for stem/progenitor cell tracking with multiple unique perfluorocarbon nanobeacons.” Investigators from Philips Medical Systems also participated in this study. This paper was published online in advance of print publication. An abstract of this paper is available through PubMed.