MR imaging for the longevity of mesenchymal stem cells labeled with poly-L-lysine-Resovist complexes.

Superparamagnetic iron oxide (SPIO) nanoparticles are emerging as ideal probes for noninvasive cell tracking. In this study, poly-L-lysine (PLL) was mixed with Resovist to form the PLL-Resovist complexes and the control of the complexes formed by PLL and Resovist and their subsequent properties was easily achievable. MSCs could be safely and efficiently labeled for MR imaging using PLL-Resovist complexes (w/w 0.01:1) and the labeled MSCs could be detected to have definite decreased signal intensity on T(2)-weight imaging until 20 days with standard 1.5 T MR equipment. This study describes a simple protocol to label MSCs using PLL-Resovist complexes and the results presented in our study can provide a basis for the application of PLL-Resovist complexes cell labeling. 2010 John Wiley & Sons, Ltd.