A nerve growth factor persistent delivery scaffold seeded with neurally differentiated bone marrow mesenchymal stem cells promoted the functional recovery of spinal cord injury in rats.

The objective was to design a scaffold that could continuously deliver nerve growth factor (NGF) combined with neurally differentiated bone marrow mesenchymal stem cells (BMSCs) to promote better recovery of spinal cord injury (SCI) in rats. BMSCs were induced to differentiate into neurons for 6 days in vitro, and then seeded on a NGF persistent delivery scaffold, both were transplanted to SCI rats in combination. Relevant extensive tests were conducted 1, 4 and 8 weeks after transplantation. The results showed that the scaffold had a stable ability to continuously release NGF and that the BMSCs on the scaffold could successfully differentiate into nerve cells. The results of Bacco, Beattie and Bresnahan (BBB) scores, inclined plane tests and electrophysiological investigations revealed that the rats in the combined regimen had better locomotor functional recovery. The results of H&E/Nissl staining, Golgi staining and immunofluorescence showed that the rats in the combined regimen retained the most neurons and had the least cavities and more formations of dendritic spines. Similarly, the positive rate was high for MAP2, NeuN and MBP, and low for GFAP. The graft of the NGF persistent delivery scaffold seeded with neurally differentiated BMSCs significantly reduced the formation of cavities and glial scars at the SCI sites and promoted neuronal survival, axonal regeneration and locomotor function recovery. Compared with the single graft of NGF persistent delivery scaffold or the single graft of neurally differentiated BMSCs, this combined scheme had a better effect in promoting the recovery of SCI.

Comparative analysis of three types of titanium mesh cages for anterior cervical single-level corpectomy and fusion in term of postoperative subsidence.

A titanium mesh cage (TMC) is a common device used for interbody fusion in anterior cervical corpectomy and fusion (ACCF) surgery, with postoperative subsidence being a common complication. Among the many influencing factors, there is a paucity of research on the end-covers of the TMC. A total of 62 patients with cervical spondylotic myelopathy were treated with single-level ACCF. TMC without end-covers (group A), traditional TMC with end-covers (group B) and new TMC with end-covers (group C) were used as the fusion device. We evaluated the surgery time, intraoperative blood loss, postoperative drainage volume, postoperative fusion, falling height of the fused segment, cervical curvature and severe subsidence rate (the number of falling height of the fused segment > 3 mm/total surgical cases in the group). In addition, the Japanese Orthopaedic Association score was used for neurological status assessment and a 10-point Visual Analog Scale for postoperative neck pain. The results showed that the falling height of the fused segment in group A (1.9 ± 0.6 mm) was significantly greater than in group B (0.9 ± 0.2 mm) and group C (0.8 ± 0.3 mm). The area of the end-covers increased gradually in group A, group B and group C, while the severe subsidence rate of group A (8/20, 40%), group B (5/22, 23%) and group C (2/20, 10%) gradually decreased. The surgery time and blood loss in group B (116.4 ± 12.2 min, 183.5 ± 36.4 mL) were higher than those in group A (90.22 ± 5.60 min, 110.4 ± 20.8 mL) and group C (92.8 ± 8.47 min, 114 ± 24.0 mL). These results showed that there was a correlation between the postoperative subsidence and the end-covers of TMC. The larger the end-cover area was, the lower the severe postoperative subsidence rate was. In addition, the design of the end-covers extending inward was more conducive to the operation.