Proliferation of human aortic endothelial cells on Nitinol thin films with varying hole sizes.

In this paper, we present the effect of micron size holes on proliferation and growth of human aortic endothelial cells (HAECs). Square shaped micron size holes (5, 10, 15, 20 and 25 μm) separated by 10 μm wide struts are fabricated on 5 μm thick sputter deposited Nitinol films. HAECs are seeded onto these micropatterned films and analyzed after 30 days with fluorescence microscopy. Captured images are used to quantify the nucleus packing density, size, and aspect ratio. The films with holes ranging from 10 to 20 μm produce the highest cell packing densities with cell nucleus contained within the hole. This produces a geometrically regular grid like cellular distribution pattern. The cell nucleus aspect ratio on the 10-20 μm holes is more circular in shape when compared to aspect ratio on the continuous film or larger size holes. Finally, the 25 μm size holes prevented the formation of a continuous cell monolayer, suggesting the critical length that cells cannot bridge is between 20 to 25 μm.