Functionalized Carbon Nanowalls as Pro-Angiogenic Scaffolds for Endothelial Cell Activation

Substrates that can be utilized to assist in expression of the inherent characteristics of cells under in vitro conditions are necessary to mimic the in vivo scenario to the maximum extent possible. We demonstrate the application of functionalized carbon nanowalls (CNW) in facilitating human endothelial cell attachment and proliferation. The CNW films were grown on silicon substrates by surface-wave microwave plasma-enhanced chemical vapor deposition (SWMWPECVD) technique. These CNW were then functionalized using nitrogen (N₂) gas plasma to form functionalized N₂ doped CNW (CNW-N₂). Characterization of CNWs revealed a uniform petal-like morphology with the individual CNW width measured to be 1-5 nm and the film thickness in the range of 10-12 μm. The N₂ functionalized CNWs proved to be highly efficient in providing cell-anchorage to the endothelial cells. Profiles of major cytoskeletal proteins revealed a higher degree of expression in the functionalized CNWs depicting the maintenance of structural integrity of cells. Interestingly, the CNW-N₂ substrate was found to promote pro-angiogenic factors in the cells, which is observed here for the first time, that could pave way for the utilization of this substrate for detailed studies of angiogenesis processes in vitro and further biomedical applications.