Implantation Effect of a Fibrin Matrix Associated with Mesenchymal Wharton’s Jelly Stromal Cells on the Course of an Experimental Spinal Cord Injury

The efficacy of immediate implantation of a fibrin matrix associated with Wharton’s jelly-derived mesenchymal stromal cells (MSC) was investigated in this study in a spinal cord injury (SCI) model. The study was conducted in white adult outbred male rats (~260 g, 4–5 months old). The injury model was based on a left-sided cross hemisection of the spinal cord at the level of T 13 –L 1 segments. Restorative treatment was based on the immediate transplantation of a human fibrin matrix associated with MSC (MSC group, n = 9) of human Wharton’s jelly (WJ) into the injury site. The reference groups had an isolated SCI (Tr group, n = 7) or the human fibrin matrix implanted into the injury site (Fb group, n = 6). The motor activity and spasticity of the paretic hindlimb were respectively evaluated using the BBB and Ashworth scales with our modifications. The morphological picture in the injury area was studied in the remote period using the silver nitrate impregnation procedure for staining longitudinal spinal cord sections. It was found that human WJ-MSC demonstrate signs of active viability, growth, and a migratory potential in the presence of a fibrin matrix in vitro. The intense increase in the motor activity of the paretic limb was limited to the first 2 weeks in the Fb group and to the first 3 weeks of follow-up observations in the MSC group. During the entire experiment, the functional level of the MSC group was behind this indicator in the Fb group, albeit significantly only during the first week of observation. The indicators for the locomotor function were 10.4 ± 1.0 points on the BBB scale (in the MSC group), 11.6 ± 2.0 points on the BBB scale (in the Fb group), and 5.9 ± 1.6 points of BBB in the Tr group 5 months later. Nevertheless, a significant difference between the values of the indicator for the MSC and Tr groups was recorded 6 weeks and 3 and 5 months after implantation. A significant advantage of the Tr group in the level of spasticity over the MSC group was recorded 6 and 7 weeks and 5 months after the injury and over the Fb group 7 weeks after the injury. No significant differences in the spasticity level between the MSC and Fb groups were recorded throughout the experiment. Thus, the immediate implantation of a fibrin matrix into the injury site of the spinal cord exerts a positive effect on the restoration of motor function in an animal’s paretic hind limb, especially in the presence of human WJ MSC.