Oriented Schwann cell growth on microgrooved surfaces

Silicon wafers bearing microgrooved surfaces with various groove width, spacing, and depth were fabricated using microlithography. The orientation of rat Schwann cells along the direction of the grooves was measured at 24 h after seeding the cells. When the width/spacing of the grooves was fixed at 10/10 μm, the mean percentage of aligned cells was 12% for grooves of 0.5 μm depth, 15% for those of 1 μm depth, and 26% for those of 1.5 μm depth (P < 0.05). When the depth of grooves was fixed at 1.5 μm, the mean percentage of aligned cells increased from 26% for width/spacing 10/10 μm, to 33% for 10/20 μm or 20/10 μm, and up to 41% for 20/20 μm (P < 0.05). On the surface with grooves of width/spacing/depth = 20/20/1.5 μm and modified by laminin, the alignment at 24 h approached 60%, versus 51% for collagen-coated surface and 41% for uncoated surface (P < 0.05). At 48 h after seeding, about 66% of the cells were aligned on the above laminin-modified surface. The groove depth influenced orientation of Schwann cells significantly. The cell alignment on 20/20/3 μm microgrooved poly(D,L-lactide-co-glycolide) 90:10 (PLGA) surfaces transferred from silicon reached 72% at 48 h and 92% at 72 h (P < 0.05). Coating this surface with laminin enhanced cell alignment only in short term (67% vs. 62% at 24 h, P < 0.05). The cell alignment guided by surface microgrooves was time dependent.