Nanofibers promote Schwann cell migration when Schwann cell proliferation is impaired

摘要

Aligned nanofibers topographically direct regenerating neurites in injured peripheral nerve. Schwann cells (SC) are vital to nerve repair; nerve guides seeded with SC promote better regeneration than those without. Because one of the roles of SC in nerve regeneration is topographic guidance, as the bands of Büngner, we hypothesized that nanofibers might similarly facilitate neurite growth if the number of SC was decreased. Aligned nanofibers were electrospun and coated with polylysine. Embryonic day 15 rat dorsal root ganglia (DRG) were cultured on nanofibers for 3 days in defined media, both with and without aphidicolin, which prevented Schwann cell proliferation. The lengths of the longest neurites in each of 10 regions around each DRG were measured. We also measured the position of the SC nucleus farthest along the path of each measured neurite. Total number of SC for each ganglion was counted using an image analysis program. Without aphidicolin, neurite lengths were equal on nanofibers and glass controls. In the presence of aphidicolin, neurite length on nanofibers and glass was equal. Aphidicolin decreased the number of SC on both nanofibers and glass. Unexpectedly, aphidicolin decreased the distance SC migrated on glass, but had no effect on SC migration on nanofibers. These data suggest that nanofibers may support SC migration even in the setting of reduced Schwann cell number. Even though nanofibers had no effect on neurite length in the setting of reduced Schwann cells, the ability of nanofibers to support Schwann cell migration suggests they may have an important role in peripheral nerve regeneration scaffolds.