TGF-β1 concentration within the cell culture medium.

<p>The TGF-β1 concentration was determined using a quantitative ELISA for human TGF-β1. The results are displayed as average ± standard deviation (n = 12). # = significant difference between the control and the BMP-2 group (both loaded and unloaded); * = significant difference between control unloaded and control loaded; $ = significantly different from the 3 days pre-culture time-point, (<i>p ≤ 0</i>.<i>05</i>).