Micropatterned Schwann Cell–Seeded Biodegradable Polymer Substrates Significantly Enhance Neurite Alignment and Outgrowth

Biomimetic strategies were employed to promote directional outgrowth of neurites in vitro by using a synergistic combination of physical, chemical, and cellular cues. Compression molded and solvent cast biodegradable polymer substrates made of poly(D,L-lactic acid) were micropatterned to form grooves on the substrate surfaces. Laminin was localized in the grooves, and rat sciatic Schwann cells were seeded on the substrates. Whole as well as dissociated rat dorsal root ganglia were seeded on the substrates along with Schwann cells, and neurite outgrowth and alignment were measured. The micropatterns provide physical guidance, laminin provides chemical cues, and the Schwann cells provide biological cues to the axons. The presence of Schwann cells in the grooves was found to promote neurite alignment as well as outgrowth and help the neurites orient even on shallower grooves and exhibit continued alignment even as the grooves degrade. The synergistic combination of physical, chemical, and cellular guidance enabled greater than 98% alignment of neurites and accelerated outgrowth of neurites in the direction of the microgrooves.