70




 Interaction Plot Data Means for log (L/W)
 Plasma Treated
 Feature, Jili .1''Ji
 0.2
 -* 10
 20
 smooth

 0.1





 0.0


 1.5 5.0
 Depth (ptm)




Figure 4.6 Interaction plot representing the change in contact guidance with depth and
feature width for plasma treated silicone elastomer.



In this graph the contact guidance data for PVECs grown on the neat sample with no

surface modification at 1.5 [im depth is included. Due to substrate production limitations

at the 5 itm depth, untreated samples were not available for analysis.

 In comparing these results to the fibronectin coated surfaces, one point that stands

out is that for the 1.5 [tm deep FN coated substrates only the 5 itm wide ridges were

significantly different from the untextured surfaces, while at 5 [im there was a

statistically significant (alpha = 0.05) higher degree of alignment. The 1.5 [tm plasma

treated surfaces did have significant alignment compared to smooth surfaces, and a

higher log (L/W) value than 1.5 [tm fibronectin samples. However, due to the surface

irregularities of the plasma treated surface explained in the previous chapter and the fact

that a silica-like layer would expose the cell to a seemingly harder substrate; direct