Enhanced stem cell tracking via electrostatically assembled fluorescent SPION-peptide complexes.
For cellular MRI there is a need to label cells with superparamagnetic iron oxide nanoparticles (SPION) that have multiple imaging moieties that are nontoxic and have increased NMR relaxation properties to improve the detection and tracking of therapeutic cells. Although increases in the relaxation properties of SPION have been accomplished, detection of tagged cells is limited by either poor cell labeling efficiency or low intracellular iron content. A strategy via a complex formation with transfection agents to overcome these obstacles has been reported. In this paper, we report a complex formation between negatively charged fluorescent monodisperse SPION and positively charged peptides and use the complex formation to improve the MR properties of labeled stem cells. As a result, labeled stem cells exhibited a strong fluorescent signal and enhanced T 2*-weighted MR imaging in vitro and in vivo in a flank tumor model.
Lee
Jae-Ho
JH
Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892-1074, USA. leejaeho@mail.nih.gov
Smith
Melissa A
MA
Liu
Wei
W
Gold
Eric M
EM
Lewis
Bobbi
B
Song
Ho-Taek
HT
Frank
Joseph A
JA
D000818:Animals; D002460:Cell Line; D002645:Chickens; D005290:Ferric Compounds / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D008856:Microscopy, Fluorescence; D010455:Peptides / Q000378:metabolism*; D019047:Phantoms, Imaging; D013194:Staining and Labeling; D055672:Static Electricity; D051598:Whole Body Imaging
D005290:Ferric Compounds; D010455:Peptides; C000499:ferric oxide; D007501:Iron