Application Of Collagen Scaffolds Loaded With MSCs Or BFGF For The Rat Hemisected Spinal Cord Injury

Objective: In this study, the lateral3mm hemisection SCI of rat model was made,and CS scaffold fused with CBD-bFGF (CS/bFGF) was implanted into the hemi-transectedgap to investigate the effects of the scaffolds combined with growth factors on the neuralrecovery after SCI.Methods:1. The model of a T9half-cut spinal cord column was made.2. All rats (n=103) were randomly divided into four groups.1) sham-operatedgroup(n=20)；2) control group(n=36；3) CS-treated group(n=26)；4) CS/bFGF group(n=21).3. The21-point Basso-Beattie-Bresnahan (BBB) scale was performed at1weekintervals after SCI for8weeks. Four and eight weeks after operation, footprint analysiswas performed, respectively. The histological evaluation was performed at4and8weekspost injury. For immunohistochemistry, the spinal cord sections were incubated withprimary antibody: anti-neurofilament, anti-glial fibrillary acidic proteinResults:1. There were seven animals with incomplete left hemisection (2from control group,3from CS group,2from CS/bFGF group) excluded from the experiment.2. At the end of the8th week, the BBB scores in the CS/bFGF and CS groups weresignificantly higher than that in the control group.3. The differences of the stride lengths of fore-and hindlimb in the SCI groupsrevealed that the CS/bFGF groups showed significant improvement in interlimbcoordination in contrast to the CS-treated and control groups at4and8weeks,respectively.4. The CS/bFGF group showed higher NF-positive neural fiber density than those of the control and CS group. The CS/bFGF group expressed lower number of GFAP+CS thanthat of the control and CS treated group at four and eight weeks after the surgery,respectively.Conclusions: This study shows that implantation of CS/bFGF into a semi-transectedSCI rat model can guide axon growth at the injury site and promote obvious improvementin functional recovery. As a result, it could be a promising alternative system for theclinical application of SCI repair.Part II: Promotion of neurological recovery in rat spinal hemisection injury bycollagen scaffold loaded with mesenchymal stem cells1. Culture，purification，detection of rat bone marrow-derived MSCsObjective: To construct a serial of cellular source for implantation in vitro.Methods: Bone marrow mononuclear cells were collected from both bilateral femoralbones by aspiration and separated by Ficoll. Cells were incubated in10%Fetal bovineserum (FBS, Gibco BRL). MSCs were confirmed by flow cytometric analysis of CD29,CD90, CD34and CD45.Results: At24h after cell culture, cells were attached. After7-9days, the cellsrapidly propagated and formed cell colonies with a swirl array. The flow cytometer（FCM）showed that the cells from rat bone marrow were positive in CD90and CD29, and werenegative in CD45and CD34.Conclusions: Pure MSCs could be acquired under the process of culture． Objective: In this work, a lateral hemisection SCI SD rat model was used to assessthe implantation effects of the collagen scaffold combined with MSCs on the functionrecovery of spinal cord injury.Methods:1. The model of a T9half-cut spinal cord column was made.2. All rats (n=105) were randomly divided into four groups.1) sham-operatedgroup(n=20)；2) control group(n=30；3) CS-treated group(n=31)；4) CS/MSC group(n=24).3. Four and eight weeks after operation, footprint analysis was performed, respectively. For immunohistochemistry, the spinal cord sections were incubated withprimary antibody: anti-neurofilament, anti-glial fibrillary acidic protein, andanti-neuron-specific enolase.Results:1. There were seven animals with incomplete left hemisection (4from control group,3from CS group,3from CS/MSC group) excluded from the experiment.2. At week8, the BBB scores in the CS/MSC and CS groups were higher than that inthe control group.3. In the ipsilateral hindlimb (left side), compared with CS and control group, theCS/MSC group showed significant improvement in interlimb coordination by measuringthe difference in stride length of fore-and hind-limb at4and8weeks.4. The NF-positive fibers could hardly be detected in and around the lesion sites of thecontrol and CS-treated group. In contrast, the CS/MSC group had significantly moreNF-positive neural fibers in and around the injury site.Conclusions: These findings show that the combined application of CS and MSCs hasan effect on neuroprotection and neurite guidance after SCI, and is an ideal approach to repairthe spinal defect and to promote functional recovery.