The effect of NeurogelTM with xenogenic neural crest stem cells implantation on the course of spasticity syndrome after experimental spinal cord injury

The aim of the study was to examine NeuroGelTM with xenogenic neural crest stem cells (NCSC) implantation on the rat’s paretic hind limb spasticity dynamics after experimental spinal cord injury. Materials and methods. Animals: outbred albino rats (5.5 months, 250 g); experimental groups: 1 — spinal cord injury only (males; n = 16); 2 — spinal cord injury + immediate homotopical transplantation of NeuroGelTM (males; n = 20); 3 — spinal cord injury + analogous transplantation of NeuroGelTM in association with adult mouse NCSC (n = 12). Group 3 consisted of male (n = 6) and female (n = 6) animals — subgroups 3m and 3f, respectively. Model of injury — left-side spinal cord hemisection at Т11; the duration of observation — 28 weeks; ipsilateral hindlimb (IHL) function indicator (FI) and spasticity indicator (SI) determination — the Вasso-Вeattie-Вresnahan scale and Ashworth scale, respectively. Results. At the 28th week, in the group 1 IHL SI was 2.5 ± 0.4 points, in group 2 — 1.7 ± 0.2 points, in group 3 — 1.6 ± 0.3 points, in a subgroup 3m — 1.6 ± 0.5 points, in a subgroup 3f — 1.7 ± 0.3 points of Ashworth scale. Significant (p < 0.05) differences between the IHL SI in the group 1 and group 2 were noted at the 7th day, 5th–7th and 12th–24th weeks, between IHL FI in the group 1 and group 3 — at the 2nd, 4th–7th and 20th weeks. The maximum prevalence of group 3 IHL FI over the group 2 IHL FI was observed at the 7th day (р = 0.13). Significant difference between IHL FI in the subgroup 3m and group 2 and between IHL FI in the subgroup 3m and group 3f was found at the 1st–2nd week. Difference between IHL FI in the subgroup 3m and group 3f was maximal during 3rd month (0.83 points of the Ashworth scale; р = 0.124). Dynamics of the group 2 IHL FI and group 3 IHL FI differs by the presence of significant growth on the 3rd, 7th week, 4th and 5th month. Unlike group 1, in group 2 and group 3 a negative correlation was observed between individual IHL FI and SI values in each of the observation terms combined with the strong positive correlation between average IHL FI and SI values along the observation period. Conclusions. NCSC xenotransplantation in association with NeuroGelTM does not change the level of spasticity compared to the implantation of NeuroGelTM only, but significantly alters its dynamics, with the trend towards worsening in the remote period of injury in the case of different donor and recipient sexes.