Figure 4. Correlating hES cell behavior to polymer properties using primary arrays.

Using data in Figure 3, regression was performed for two properties listed at the top of each plot: colony formation vs. polymer roughness (a), colony formation vs. polymer indentation elastic modulus in the hydrated state (b), colony formation vs. wettability (c), and colony formation as a function of both polymer wettability and indentation elastic modulus in the hydrated state (d). After performing linear regression, 2^nd order polynomial regression, and power law regression, only the regression with the highest R² is shown in each plot (dashed line). Insets in parts b are in semi-log format to indicate behavior at low modulus values. Data is sorted into groups of 20-25 spots as a function of increasing WCA, roughness, or modulus. For contour plot, interpolation between data points (groups of 20-25 spots) was performed on Matlab (see methods). Abscissa error bars represent the standard error of the WCA, roughness, or modulus for a given group of 20-25 spots. In plots a, b, and c, ordinate error bars represent the standard error of the mean of the colony formation frequency of three replicates for a given group.