Abstract:
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Purpose: To assess the feasibility of Gadophrin-2 to trace intravenously injected human hematopoietic progenitor and stem cells in athymic mice using magnetic resonance (MR) imaging, optical imaging (OI) and fluorescence microscopy.
Methods and Materials: Hematopoietic progenitor and stem cells were labeled with Gadophrin-2 (Schering AG, Berlin, Germany), a paramagnetic and fluorescent metalloporphrin, using established transfection techniques with cationic liposomes. The labeled cells were evaluated in vitro with electron microscopy and ICP-AES. Then, 1*106-3*108 labeled cells were injected into 14 nude Balb/c mice and the in vivo cell distribution was evaluated with MR and OI before as well as 4, 24 and 48 hours (h) after intravenous injection (p.i.). 3 additional non-treated mice served as controls. The contrast agent effect was determined quantitatively for MR by calculating ΔSI(%)-data. After completion of in vivo imaging studies, OI and fluorescence microscopy of excised organs was performed.
Results: Intracellular cytoplasmatic uptake of Gadophrin-2 was proven with electron microscopy. Spectrometry determined an uptake of 31.555 nmol Gd per 106 cells. After intravenous injection, the distribution of Gadophrin-2-labeled cells in nude mice could be visualized by MR, OI and fluorescence microscopy. At 4 h p.i., the transplanted cells mainly distributed to lung, liver and spleen and, 24 h p.i., also to the bone marrow. Minimal detectable cell numbers were 107 cells with MR, 106 cells with OI and depiction of single cells with fluorescence microscopy. Fluorescence microscopy confirmed the distribution of the contrast agent containing transplanted human cells within the murine organs.
Conclusion: Gadophrin-2 is suited as a trifunctional contrast agent for MR imaging, optical imaging and fluorescence microscopy and may be used to combine advantages of either imaging modality for an in vivo tracking of intravenously injected hematopoietic progenitor and stem cells.
Questions about this event email: daldrup@roe.med.tu-muenchen.de
Daldrup-Link MD, H,
Stem Cell Tracking with Gadophrin-2: A Trifunctional Contrast Agent for MR Imaging, Optical Imaging, and Fluorescence Microscopy. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3102668.html
