Abstract
Summary
Collagen scaffolds loaded with mesenchymal stem cells accelerate neurological recovery in rat spinal hemisection.
Objective
To investigate the implantation effects of the collagen scaffold (CS) combined with mesenchymal stem cells (MSCs) on the function recovery of spinal cord injury (SCI) with a lateral hemisection SCI SD rat model.
Methods
MSCs were prepared from SD rat bone marrow. A T9 hemisection SCI SD rat model was developed with the removal of a 3mm left hemicord segment and a bundle of 2mm×2mm×3mm CS loaded with MSCs (5×105 cell/20μl/bundle, CS/MSC) was implanted into hemi-transected gap. Four groups were randomly divided: the sham group without SCI, the control group with SCI, the CS-treated group with SCI and implanted CS, the CS/MSC-treated group with SCI and implanted CS/MSC. The neurological function recovery was evaluated by the 21-point Basso-Beattie-Bresnahan (BBB) scale and footprint analysis before and after SCI. The histological evaluation was performed at 4 and 8 weeks post injury by H&E staining and immunohistochemistry for neurofilament (NF), glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NES).
Results
All the rats in the CS/MSC-treated group were alive while some rats were dead in the control and CS-treated groups. The BBB scores before the operation and at 1 week intervals after SCI for 8 weeks showed that the left hindlimbs function of CS/MSC-treated group restored faster and better than that of the control and CS-treated groups. In the ipsilateral hindlimb (left side), compared to the control and CS-treated group, the CS/MSC-treated group showed significant improvement in interlimb coordination by measuring the difference in stride length of fore- and hind-limb at 4 and 8 weeks, respectively. The base of support in CS/MSC-treated group was significantly reduced, and at 8 weeks, approximate equal to that of the sham group. The CS/MSC-treated group also showed smaller angle of rotation compared to the control and CS-treated groups. Histologically, compared to the control and CS-treated groups, spinal cord sections stained with H&E showed more tissue preservation in and around the injury site in the CS/MSC-treated group. Meanwhile, more NF-positive neural fibers, more density of NES staining and less GFAP positive astrocytes were observed in and around the injury site in the CS/MSC-treated group.
Conclusions
These findings show that the combined application of CS and MSCs has an effect on neuroprotection and neurite guidance in the SCI rat model. It is well suggested the system would be an ideal approach to repair the spinal defect and to promote functional recovery after SCI.
