Adhesion, distribution, and migration of differentiated and undifferentiated mesenchymal stem cells (MSCs) seeded on nerve allografts

Background: Although undifferentiated MSCs and MSCs differentiated into Schwann-like cells have been extensively compared in vitro and in vivo, studies on the ability and efficiency of differentiated MSCs for delivery into nerve allografts are lacking. As this is essential for their clinical potential, the purpose of this study was to determine the ability of MSCs differentiated into Schwann-like cells to be dynamically seeded on decellularized nerve allografts and to compare their seeding potential to that of undifferentiated MSCs. Methods: Fifty-six sciatic nerve segments from Sprague Dawley rats were decellularized, and MSCs were harvested from Lewis rat adipose tissue. Control and differentiated MSCs were dynamically seeded on the surface of decellularized allografts. Cell viability, seeding efficiencies, cell adhesion, distribution, and migration were evaluated. Results: The viability of both cell types was not influenced by the processed nerve allograft. Both cell types achieved maximal seeding efficiency after 12 h of dynamic seeding, albeit that differentiated MSCs had a significantly higher mean seeding efficiency than control MSCs. Dynamic seeding resulted in a uniform distribution of cells among the surface of the nerve allograft. No cells were located inside the nerve allograft after seeding. Conclusion: Differentiated MSCs can be dynamically seeded on the surface of a processed nerve allograft, in a similar fashion as undifferentiated MSCs. Schwann-like differentiated MSCs have a significantly higher seeding efficiency after 12 h of dynamic seeding. We conclude that differentiation of MSCs into Schwann-like cells may improve the seeding strategy and the ability of nerve allografts to support axon regeneration.