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

Abstract

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 Â 10 6 labeled (n ¼ 12) or unlabeled MSCs (n ¼ 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 6 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.

The effect of stem cells in bridging peripheral nerve defects: a meta-analysis

“…40,48 The proportion of cells that survived was reported to be up to 38%. 42 Furthermore, the transition from stem cell to Schwann cell has been encountered previously and thus indicates that this could be a vital factor in explaining the beneficial effect. 6,7,39,45 Schwann cells, however, not only myelinate; Höke et al 14 showed that the Schwann cell phenotype can be modulated, for example, into motor or sensory Schwann cells.…”

Peripheral Nerve Repair: Monitoring by Using Gadofluorine M–enhanced MR Imaging with Chitosan Nerve Conduits with Cultured Mesenchymal Stem Cells in Rat Model of Neurotmesis

“…MSCs were harvested and expanded as previously described ( 17 ). The tissue-engineered constructs were prepared according to the previously reported method ( 5 ).…”

Distal segment extracts of the degenerated rat sciatic nerve induce bone marrow stromal cells to express Schwann cell markers in vitro

“…The most acceptable explanation is that MSCs differentiate into Schwann-like cells to produce large amounts of various cytokines and growth factors that may promote neural cell survival and neuritogenesis, or take part in myelin formation directly [7,16,20,22,26]. Because implanted MSCs generate neural phenotypes specific to the lesion site [4,17,18,23,24], another transdifferentiation mechanism of MSCs is believed to be due to spontaneous fusion of MSCs with host cells rather than actual transdifferentiation [27].…”