the ridge, and the width is perpendicular. With the images aligned vertically, the

measurement lines can be constrained by the software to perfectly vertical or horizontal,

and so by using that method the maximum length and maximum width of each nucleus

was measured and entered into an Excel spreadsheet. A 5 x 5 grid was superimposed on

the images, and 5 nuclei were chosen per image, each from a separate square of the grid.

Using this method, at least 20 nuclei per sample setting were quantified.


 Results and Discussion

Contact Guidance on Textured Surfaces

 As discussed in Chapter 2, surface ridges and grooves typically act to elongate

cells along the ridge. This phenomenon is mainly reported in qualitative fashion, and

fibroblasts are predominant as the cell system, since they are relatively easy to grow and

have shown good results in terms of contact guidance. Quantitative studies of contact

guidance on textured surfaces have used SEM and phase contrast microscopy to map the

entire cell body and try to determine its alignment. A serious limitation to this method is

the fact that unless the cells are isolated from others, the cellular dimensions and

alignment can be difficult to determine. From personal experience, cells that are not in

contact with others are typically more elongated and tend to show greater contact

guidance than confluent cells. Other methods to quantify contact guidance stain actin

filaments and other cytoskeleton components to detect the alignment of the interior stress

fibers with fluorescent or confocal microscopy.

 For cells in this study, groups of cells were examined, rather than individual cells

apart from the rest of the culture. The main purpose of this project was to examine the

effects of modulus as a factor involved in the ability of a substrate to direct cell growth.