Optimal micropattern dimensions enhance neurite outgrowth rates, lengths, and orientations

Micropattern dimensions can significantly influence neurite outgrowth orientation, rate, and length. Laminin micropatterns of various widths from 10 to 50 mu m at 10 mu m intervals separated by 40 mu m spaces were generated on poly(methyl methacrylate) surfaces using microscale plasma-initiated patterning (mu PIP). Dissociated dorsal root ganglion (DRG) neurons were seeded on the micropatterned surfaces and cultured for 24 h in serum-free media. Neurite outgrowth numbers, lengths, rates, and orientations were measured on all micropatterned substrates. The results indicated that the dimension of the laminin pattern influenced the neurite outgrowth length, rate, and orientation, but not the numbers of neurite outgrowth. Neurons on more than 30 mu m wide laminin pattern showed faster neurite outgrowth compared to other dimensions, and relatively low orientation at 50 mu m pattern dimensions. Neurites at 40 mu m laminin pattern widths demonstrated the fastest outgrowth rates and were highly oriented. The 40 mu m laminin dimension is wide enough to provide sufficient laminin amounts for neuron growth and narrow enough to efficiently guide neurites. Based on these results, adhesive protein micropatterns of 40 mu m dimensions are recommended when investigating DRG neurons.