In vivo MR imaging tracking of transplanted mesenchymal stem cells in a rabbit model of acute peripheral nerve traction injury

• Published in: Journal of magnetic resonance imaging 2010-11, Vol.32 (5), p.1076-1085
• Main Authors: Shen, Jun, Duan, Xiao-Hui, Cheng, Li-Na, Zhong, Xiao-Mei, Guo, Ruo-Mi, Zhang, Fang, Zhou, Cui-Ping, Liang, Bi-Ling
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Cell Proliferation; Cell Survival; Contrast Media; Gadolinium DTPA; magnetic resonance imaging; Magnetic Resonance Imaging - methods; Mesenchymal Stem Cell Transplantation; mesenchymal stem cells; Mesenchymal Stromal Cells - physiology; Nerve Regeneration; peripheral nerve injury; Polyethyleneimine - analogs & derivatives; Rabbits; Rhodamines; Sciatic Nerve - injuries; Sciatic Nerve - pathology; Sciatic Nerve - physiology; stem cell transplantation
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.22353

Purpose To investigate in vivo MRI tracking mesenchymal stem cells (MSCs) in peripheral nerve injures using a clinically available paramagnetic contrast agent (Gd‐DTPA) and commercially available rhodamine‐incorporated transfection reagents (PEI‐FluoR). Materials and Methods After bone marrow MSCs were labeled with Gd‐DTPA and PEI‐FluoR complex, the labeling efficacy and longevity of Gd‐DTPA maintenance were measured and cell viability, proliferation, and apoptosis were assessed. Thirty‐six rabbits with acute sciatic nerve traction injury randomly received 1 × 106 labeled (n = 12) or unlabeled MSCs (n = 12) or vehicle alone injection. The distribution and migration of implanted cells was followed by MRI and correlated with histology. The relative signal intensity (RSL) of the grafts was measured. Results The labeling efficiency was 76 ± 4.7% and the labeling procedure did not influence cell viability, proliferation, and apoptosis. A persistent higher RSL in grafts was found in the labeled group compared with the unlabeled and vehicle groups until 10 days after transplantation (P < 0.05). The distribution and migration of labeled cells could be tracked by MRI until 10 days after transplantation. Transplanted MSCs were not found to transdifferentiate into Schwann‐like cells within 14‐day follow‐up. Conclusion Labeling MSCs with the dual agents may enable cellular MRI of the engraftment in the experimental peripheral nerve injury. J. Magn. Reson. Imaging 2010;32:1076–1085. © 2010 Wiley‐Liss, Inc.