Therapeutic effects with magnetic targeting of bone marrow stromal cells in a rat spinal cord injury model.

STUDY DESIGN Experimental rat animal study using a new cell delivery system. OBJECTIVE To investigate the therapeutic effects with magnetic targeting of bone marrow stromal cells (BMSCs) in a rat spinal cord injury (SCI) model. SUMMARY OF BACKGROUND DATA Several methods to deliver therapeutic agents have been used for the treatment of SCI in animal studies. However, the most appropriate administration method for clinical application has not been established. Previously, we reported the development of a new cell delivery system using magnetic targeting. This system has potential as a clinical application for a minimally invasive and efficient transplant method in SCI. METHODS Contusion SCI was induced by placing a 25 g rod onto the spinal cord for 90 seconds in adult SD rats. A neodymium magnet was placed in the paravertebral muscles at the T7 level in the magnet group, whereas a nonmagnet metal was placed at the same spinal cord level in the nonmagnet group. Magnetically labeled BMSCs were injected into the subarachnoid space in both the magnet and nonmagnet group. RESULTS Aggregations of the BMSCs were detected on the surface of the injured spinal cord in the magnet group, whereas few BMSCs were observed in the nonmagnet group. Hindlimb motor function of the magnet group demonstrated significant improvement compared with that of the nonmagnet group. CONCLUSION This cell delivery system may be a useful method for future clinical application in the treatment of SCI.