The aim was to evaluate the potential effect of bone marrow-derived mesenchymal stem cells
(BMSC) and BMSC-EX in the sciatic nerve injury. Forty-five rats were divided into four groups, i.e.
Group I control no surgery or treatment, Group II sciatic nerve crush surgery and 1 week postsurgery,
Group III sciatic nerve crush injury was treated with BMSC, and Group IV sciatic nerve
crush injury was treated with BMSC-EX. All animal groups were euthanized 2 weeks after
treatment. Sciatic nerves were examined histologically and immunohistochemically. Group II
showed various histological changes, i.e. vacuolation, degeneration and loss of nerve fibers.
Group II showed a significant increase in collagen fibers, but with significant reduction in osmium
tetroxide (OsO4)-stained myelin sheaths and neurofilament immunostaining compared to Group
I. Group II also revealed distortion and disruption of myelinated nerve fibers. Groups III and IV
showed significant improvement of both histological and immunohistochemical changes in
Group II. BMSC and BMSC-EX were shown to improve axonal regeneration.