Lithium chloride combined with human umbilical cord blood mesenchymal stem cell transplantation for treatment of spinal cord injury in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of lithium chloride combined with human umbilical cord blood mesenchymal stem cell (hUCB-SCs) transplantation in the treatment of spinal cord injury in rats.</p><p><b>METHODS</b>Eighty female SD rats with complete T9 spinal cord transaction were randomized into 4 groups (n=20), namely the control group (group A), lithium chloride group (group B), hUCB-SCs group (group C) and hUCB-SCs(+) lithium chloride group (group D). On days 1 and 3 and the last days of the following weeks postoperatively, the motor function of the hindlimb of the rats were evaluated according to the BBB scores. At 8 weeks, all the rats were sacrificed and the spinal cords were taken for morphological observation. The spinal cord tissues at the injury site were observed with Brdu nuclear labeling to identify the survival and migration of the transplanted SCs. The regeneration and distribution of the spinal nerve fibers were observed with fluorescent-gold (FG) spinal cord retrograde tracing.</p><p><b>RESULTS</b>Brdu labeling showed that the transplanted hUCB-SCs survived and migrated in the spinal cord 8 weeks postoperatively in groups C and D. FG retrograde tracing identified a small amount of pyramidal cells that migrated across the injury site in groups C and D. The BBB scores of the hindlimb motor function 8 weeks postoperatively were 4.11∓0.14, 4.50∓0.15, 8.31∓0.11 and 11.15∓0.18 in groups A, B, C and D, respectively.</p><p><b>CONCLUSION</b>Lithium chloride can promote the survival and differentiation of hUCB-SCs into neural cells at the injury site. Lithium chloride combined with hUCB-SCs transplantation may accelerate functional recovery of the hindlimbs in rats with complete transection of the spinal cord.</p>

Effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord and establish a procedure to construct an acellular rat spinal cord allograft retaining intact matrix fibers for repairing spinal cord injuries.</p><p><b>METHODS</b>Fifteen segments of rat spinal cord were divided randomly into 3 groups and subjected to mechanical vibration at the frequency 80 r/min (group A, n=5), 120 r/min (group B, n=5), and 160 r/min (group C, n=5) respectively. The spinal cord was treated with Triton X-100 and sodium deoxycholate at room temperature and washed with distilled water. The specimens were observed microscopically with HE staining, and the ultrastructure was observed using scanning electron microscope.</p><p><b>RESULTS</b>In group A, the spinal cord specimens contained numerous cells and neural sheaths. Vibration at 120 and 160 r/min (in groups B and C) resulted in depletion of all the cells, axons and neural sheaths from the spinal cord after treatment with Triton X-100 and sodium deoxycholate. The acellular spinal cord consisted of a meshwork of the matrix fibers in longitudinal arrangement. In group C, however, obvious disruption of both the spinal dura mater and the matrix fiber occurred in the acellular spinal cord.</p><p><b>CONCLUSION</b>All the cells, axons and neural sheaths in the spinal cord can be removed by chemical extraction with Triton X-100 and sodium deoxycholate. Mechanical vibration at suitable frequency may cell preserve the 3-dimensional structure of the matrix fibers. The acellular spinal cord scaffold may serve as an ideal material for constructing tissue-engineered spinal cord.</p>