Magnetic resonance imaging probes for labeling of chondrocyte cells.

Recent progress in cell therapy research has raised the need for non-invasive monitoring of transplanted cells. Magnetic resonance imaging (MRI) of superparamagnetic iron oxide (SPIO) labeled cells have been widely used for high resolution monitoring of the biodistribution of cells after transplantation. Here we report that self-assembly of amphiphilic polyethylenimine (PEI)/SPIO nanocomposites can lead to the formation of ultrasensitive MRI probes, which can be used to label chondrocyte cells with good biocompatibility. The labeled cells display strong signal contrast compared to unlabeled ones in a clinical MRI scanner. This probe may be useful for noninvasive MR tracking of implanted cells for tissue regeneration.