Inside-out Vein Graft With Schwann Cell-like Differentiated Bone Marrow Stromal Cells Repair Facial Nerve Defect

Facial nerve defects, caused by tumor surgery or trauma, are usually overcomeby autologous nerve graft transplantation. And the nerve tubulization is an availablealternative repair technique. In the peripheral nerve tissue engineering, theautologous Schwann cells are the perfect seed cells. But disadvantages includelosing the innervation in the donor area and adding a second operation scar. Bonemarrow stromal cells (MSC) are multipotent stem cells and can be induced todifferentiate into different kinds of cells such as some Schwann-like cells whichcould be the alternative cells for Schwann cells.Objective: The main purpose of this study is to induce the rabbit MSCsdifferentiated into the Schwann-like cells and investigate the role of these cells incombination with the autologous inside-out vein conduit on facial nerveregeneration.Method: The MSCs were harvested from the postnatal rabbit in 7days andcultured in the inducing medium includingβ-ME, ATRA and bFGF et al. The leftfacial nerves of 16 rabbits were transected and were sutured to bridge the proximaland distal stumps by using the inside-out vein tubes respectively which filled withMSCs and transdifferentiated MSCs in two groups. At 4,8 and 12 weeks aftersurgery, a series of exaninations were performed to observe the facial nerveregeneration.Results: The differentiated MSCs were morphologically different from theoriginal MSCs and resembled the Schwann cells. A part of them showed S-100 and GFAP positive. Appropriate function recovery was noted in the groups received thecell conduits as well as the number of myelinated fibers and the myelin thicknesswere significantly increased in the group with the transdifferentiated MSCs.Conclusion: The rabbit bone marrow stromal cells are able to induce anddifferentiate to Schwann-like cells and can provide satisfied ability to enhance thefacial nerve regeneration combined with the inside-out vein grafts.