After injury to the CNS, the anatomical organization of the tissue is disrupted, posing a barrier to
the regeneration of axons. Meningeal cells, a central participant in the CNS tissue response to injury,
migrate into the core of the wound site in an unorganized fashion and deposit a disorganized
extracellular matrix (ECM) that produces a nonpermissive environment. Previous work in our laboratory
has shown that the presentation of nanometer-scale topographic cues to these cells influences
their morphological, cytoskeletal, and secreted ECM alignment. In the present study, we provided
similar environmental cues to meningeal cells and examined the ability of the composite
construct to influence dorsal root ganglion regeneration in vitro. When grown on control surfaces
of meningeal cells lacking underlying topographic cues, there was no bias in neurite outgrowth. In
contrast, when grown on monolayers of meningeal cells with underlying nanometer-scale topography,
neurite outgrowth length was greater and was directed parallel to the underlying surface topography
even though there exists an intervening meningeal cell layer. The observed outgrowth was
significantly longer than on laminin-coated surfaces, which are considered to be the optimal substrata
for promoting outgrowth of dorsal root ganglion neurons in culture. These results suggest
that the nanometer-level surface finish of an implanted biomaterial may be used to organize the encapsulation
tissue that accompanies the implantation of materials into the CNS. It furthermore suggests
a simple approach for improving bridging materials for repair of nerve tracts or for affecting
cellular organization at a device–tissue interface.
