Figure 3.
Magnetic targeting increases short-term cell retention in the hearts and reduces off-target migration. A and B: Representative images of hearts from the Fe-CDC and Fe-CDC + Magnet group 24 hours after cell injection. Cells are visible as a yellow-brown area in the Fe-CDC + Magnet group (B; red arrow) but not in the Fe-CDC group (A). C-K: Representative fluorescence imaging of organs harvested at 24 hours after cell injection. CDCs were labeled with flash-red-conjugated SPMs. Exposure time was set at the same level for each imaging procedure. More fluorescence was detected in a heart from the Fe-CDC + Magnet group (F) than in the Fe-CDC group (C). Red fluorescence signals were detectable in the lungs and spleens, but less so in the lungs and spleens from the Fe-CDC + Magnet group (G and H) than in those from the Fe-CDC group (D and E). As a negative control, excised organs from the CDC group (animals were injected with non-labeled cells) were also imaged; no signals were detected from any such organs (I-K).