Monitoring Cells with MRI

Magnetic resonance evaluation of human mesenchymal stem cells in corpus cavernosa of rats and rabbits.
Song YS, Ku JH, Song ES, Kim JH, Jeon JS, Lee KH, Kim SJ, Cheong HJ, Lim IS, Choi D, Won JH
AIM: To investigate whether the biological process of superparamagnetic iron oxide (SPIO)-labeled human mesenchymal stem cells (hMSCs) may be monitored non-invasively by using in vivo magnetic resonance (MR) imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits.
METHODS: The labeling efficiency and viability of SPIO-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period.
RESULTS: hMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than 1 X 10 (5) concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections.
CONCLUSION: SPIO-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated noninvasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.
PMID: 17486277 [PubMed – indexed for MEDLINE]