Diffusion tensor imaging predicting neurological repair of spinal cord injury with transplanting collagen/chitosan scaffold binding bFGF.

Prognosis and treatment evaluation of spinal cord injury (SCI) are still in the long-term research stage. Prognostic factors for SCI treatment need effective biomarker to assess therapeutic effect. Quantitative diffusion tensor imaging (DTI) may become a potential indicators for assessing SCI repair. However, its correlation with the results of locomotor function recovery and tissue repair has not been carefully studied. The aim of this study was to use quantitative DTI to predict neurological repair of SCI with transplanting collagen/chitosan scaffold binding basic fibroblast growth factor (bFGF). To achieve our research goals, T10 complete transection SCI model was established. Then collagen/chitosan mixture adsorbed with bFGF (CCS/bFGF) were implanted into rats with SCI. At 8 weeks after modeling, implanting CCS/bFGF demonstrated more significant improvements in locomotor function according to Basso-Beattie-Bresnahan (BBB) score, inclined-grid climbing test, and electrophysiological examinations. DTI was carried out to evaluate the repair of axons by diffusion tensor tractgraphy (DTT), fractional anisotropy (FA) and apparent diffusion coefficient (ADC), a numerical measure of relative white matter from the rostral to the caudal. Parallel to locomotor function recovery, the CCS/bFGF group could significantly promote the regeneration of nerve fibers tracts according to DTT, magnetic resonance imaging (MRI), Bielschowsky's silver staining and immunofluorescence staining. Positive correlations between imaging and locomotor function or histology were found at all locations from the rostral to the caudal (P < 0.0001). These results demonstrated that DTI might be used as an effective predictor for evaluating neurological repair after SCI in experimental trails and clinical cases.

Collagen/heparin sulfate scaffolds fabricated by a 3D bioprinter improved mechanical properties and neurological function after spinal cord injury in rats.

Effective treatments promoting axonal regeneration and functional recovery for spinal cord injury (SCI) are still in the early stages of development. Most approaches have been focused on providing supportive substrates for guiding neurons and overcoming the physical and chemical barriers to healing that arise after SCI. Although collagen has become a promising natural substrate with good compatibility, its low mechanical properties restrict its potential applications. The mechanical properties mainly rely on the composition and pore structure of scaffolds. For the composition of a scaffold, we used heparin sulfate to react with collagen by crosslinking. For the structure, we adopted a three-dimensional (3D) printing technology to fabricate a scaffold with a uniform pore distributions. We observed that the internal structure of the scaffold printed with a 3D bioprinter was regular and porous. We also found that both the compression modulus and strengths of the scaffold were significantly enhanced by the collagen/heparin sulfate composition compared to a collagen scaffold. Meanwhile, the collagen/heparin sulfate scaffold presented good biocompatibility when it was co-cultured with neural stem cells in vitro. We also demonstrated that heparin sulfate modification significantly improved bFGF immobilization and absorption to the collagen by examining the release kinetics of bFGF from scaffolds. Two months after implantating the scaffold into transection lesions in T10 of the spinal cord in rats, the collagen/heparin sulfate group demonstrated significant recovery of locomotor function and according to electrophysiological examinations. Parallel to functional recovery, collagen/heparin sulfate treatment further ameliorated the pathological process and markedly increased the number of neurofilament (NF) positive cells compared to collagen treatment alone. These data suggested that a collagen/heparin sulfate scaffold fabricated by a 3D bioprinter could enhance the mechanical properties of collagen and provide continuous guidance channels for axons, which would improve the neurological function after SCI. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1324-1332, 2017.

[Effect of Panax NotoginSeng Saponins on motor evoked potentials of spinal cord injured rats with motion function].

OBJECTIVE: To investigate the effect of Panax NotoginSeng Saponins(PNS) on functional recovery of rats with spinal cord injury (SCI) after exercise. METHODS: SD normal rats were randomly divided into normal control group (Normal) and control group (Sham), spinal cord injury (SCI) and spinal cord injury (SCI) + panax notoginseng saponins group (PNS) (n=8). All rats were given basso beattie bresnahan motor function score (BBB) and motor evoked potentials (MEP) examination to observe rat hind limb motor function recovery before operation and 1,3,7,14,21,28 days after operation. RESULTS: After operation, the BBB scores of Sham group, PNS group, SCI group were lower than that of normal; MEP amplitude was lower than that of normal group; the incubation time was prolonged compared with that in normal group. In PNS group compared with that in the SCI group, BBB scores at 7,14,21 and 28 days was significantly different(P<0.05). There were significant differences in the latency (Lat) and amplitude(Amp) of MEP within PNA subgroups or between the PNS and the SCI groups at 7,14,21,28 days(P<0.05). CONCLUSIONS: PNS can promote the recovery of motor function after SCI in rats.