ELISA Assays for β-NGF (a) and VEGF-A (b).

<p>Protein concentration per cell in the growth media at days 3, 7, and 14, was normalized using the cell numbers from the dsDNA (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139820#pone.0139820.g005" target="_blank">Fig 5</a>) results. Data collected from three different samples at each time point. Starred bars indicate significant difference between groups at each time point. Significant differences between time points not shown.