Pre-osteoblast proliferation, integrin activation, cytoskeletal organization, and focal adhesion on PCU and CNT/PCU composites.

<p>(a) Actin cytoskeleton (green) and focal adhesions (red) of pre-osteoblasts grown on the PCU (a, d), 10% CNT/PCU (b, e), and 50% CNT/PCU (c, f) surfaces after 24 hrs. (g) Fold change of mRNA expression levels of α_1, α₂, α_5, and α_v integrin and of (h) β₁ and β₃ integrin in pre-osteoblasts grown on the PCU (orange), 10% CNT/PCU (gray), and 50% CNT/PCU (dark gray) surfaces were assessed by qPCR after 24 hrs in culture. (i) Fold change of pre-osteoblast cell proliferation on CNT/PCU composites compared with that on the pure PCU surface after 24 hrs. All data represent the mean ± SEM (<i>n</i> = 3). *<i>p</i> < 0.05, **<i>p</i> < 0.01, ***<i>p</i> < 0.001 <i>vs</i>. control (PCU) and ^###<i>p</i> < 0.001 <i>vs</i>. CNT/PCU composites.