Directed growth of adult human white matter stem cell-derived neurons on aligned fibrillar collagen.

The nanoscale spatial organization of collagen fibrils as major constituents of extracellular matrices is believed to be crucial for neurite guidance in neural development and repair. To systematically study the influence of collagen fibril alignment, length, and density on human neuronal cell behavior, we used our novel technology to produce aligned collagen matrices by shear flow deposition using a microfluidic channel system and applied these surfaces to functional human neurons and glia derived from white matter neural stem cell cultures. Neurites on aligned collagen were highly oriented in the direction of the underlying fibrils, whereas neurites on nonaligned collagen or poly-d-lysine did not exhibit a preferred direction but formed a web-like morphology. Although the best alignment of collagen fibers in our study was seen using long fibrils at low density, the best neurite orientation was achieved on long fibrils at high density. Neurite outgrowth was enhanced on aligned collagen compared with nonaligned collagen or poly-d-lysine substrates, whereas neural differentiation and cell survival were not influenced by the type of substrate. Our data show that size and density of aligned collagen fibrils are crucial for axonal sprouting of human neural stem cell-derived neurons. The flexibility of our technology, allowing collagen matrix qualities to be adapted to the neuronal cell type of interest, is thus a major advantage for therapeutic reconstruction of axonal pathways in the central or peripheral nervous system.