Differential Effects of TiO2 Nanotubes on Vascular Cells

The response of primary human endothelial (ECs) and vascular smooth muscle cells (VSMCs) to TiO2 nanotube arrays is studied through gene expression analysis. Microarrays revealed that nanotubes enhanced EC proliferation and motility, decreased VSMC proliferation, and decreased expression of molecules involved in inflammation and coagulation in both cell types. Network generated from significantly affected genes suggests that cells may be sensing nanotopographical cues via pathways previously implicated in sensing shear stress. DNA microarrays were used to analyze the response of primary human endothelial (ECs) and vascular smooth muscle cells (VSMCs) to nanotopographical TiO2 surfaces. The experiment incorporated a 1 color design and used Agilent arrays that contained roughly 44,00 60mer probes that provide complete coverage of the human genome. 19 arrays were hybridized and represent 4 biological replicates for each group ( with the exception of group VSMC-NT30, which has 3 biological replicates). Data was analyzed separately for each cell type ( EC or VSMC). Gene expression comparisons were made between control cells grown on flat titanium (Ti) and cells grown on either 30nm nanotubes (NT30) or 100nm nantubes ( NT-100).