Cell labeling with the positive MR contrast agent Gadofluorine M.
The purpose of this study was to label human monocytes with Gadofluorine M by simple incubation for subsequent cell depiction at 1.5 and 3 T. Gadofluorine M displays a high r(1) relaxivity and is spontaneously phagocytosed by macrophages. Human monocytes were incubated with Gadofluorine M-Cy at varying concentrations and incubation times and underwent MR imaging at 1.5 and 3 T at increasing time intervals after the labeling procedure. R1-relaxation rates and r1 relaxivities of the labeled cells and non-labeled controls were determined. Cellular contrast agent uptake was examined by fluorescence microscopy and quantified by ICP-AES. Efficient cell labeling was achieved after incubation of the cells with 25 mM Gd Gadofluorine M for 12 h, resulting in a maximal uptake of 0.3 fmol Gd/cell without impairment of cell viability. Fluorescence microscopy confirmed internalization of the fluorescent contrast agent by monocytes. The r1 relaxivity of the labeled cells was 137 mM(-1)s(-1) at 1.5 T and 80.46 mM(-1)s(-1) at 3 T. Imaging studies showed stable labeling for at least 7 days. Human monocytes can be effectively labeled for MR imaging with Gadofluorine M. Potential in vivo cell-tracking applications include targeting of inflammatory processes with Gadofluorine-labeled leukocytes or monitoring of stem cell therapies for the treatment of arthritis.
Henning
Tobias D
TD
Department of Radiology, University of California in San Francisco, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
Saborowski
Olaf
O
Golovko
Daniel
D
Boddington
Sophie
S
Bauer
Jan S
JS
Fu
Yanjun
Y
Meier
Reinhard
R
Pietsch
Hubertus
H
Sennino
Barbara
B
McDonald
Donald M
DM
Daldrup-Link
Heike E
HE
D002478:Cells, Cultured; D003287:Contrast Media / Q000493:pharmacokinetics*; D005466:Fluorocarbons; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018613:Microscopy, Confocal; D009000:Monocytes / Q000378:metabolism*; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D013054:Spectrophotometry, Atomic; D013194:Staining and Labeling
D003287:Contrast Media; D005466:Fluorocarbons; D009942:Organometallic Compounds; C517961:gadofluorine M