Comparison of the Effects of Intratubal Injection of Adipose-Derived Mesenchymal Stem Cells in a Rat Sciatic Nerve Transection: An Experimental Study.

This study was designed to evaluate the efficacy of epineural tubulization (ENT) with or without intratubal application of adipose-derived mesenchymal stem cells (ASCs) in the rat model of sciatic nerve transection. After formation of 1-cm defect in the left sciatic nerve and ENT, 32 adults female Wistar albino rats were separated into 4 groups (n = 8 for each) including ENT per se (group 1; ENT group) and ENT plus intratubal ASC injection groups killed on day 21 (group 2; ENT-ASC-21-day group), 60 days (group 3; ENT-ASC-60-day group), and 120 days (group 4; ENT-ASC-120-day group). Functional (sciatic function index, hip circumference, withdrawal reflex latency, muscle weight ratio), electrophysiological, histomorphometric, and immunohistochemical analyses were performed in each group. Sciatic function index was significantly higher (-51.98 ± 5.94, P < 0.01) and withdrawal reflex latency was shorter (-6.21 ± 2.14, P < 0.01), in the group 4 as compared with all other groups on day 21. Amplitude of contraction was significantly lower in the group 4 as compared with all other groups (0.22 ± 0.05 vs 0.34 ± 0.07, 0.50 ± 0.11, and 0.61 ± 0.16, P < 0.01 for each). Immunohistochemical analysis revealed presence of green fluorescent protein, vimentin-stained cells, and single neural progenitor cells indicating that induction of neuronal differentiation by ASCs and direct involvement of ASCs within the axonal structure alongside extension of ASCs to the muscular layer of the group 4. In conclusion, our findings revealed that use of ENT plus intratubal ASC injection in a rat sciatic nerve transection model was associated with satisfactory functional outcome and improved peripheral axonal regeneration along with stem cell neural differentiation.