Fabrication of Biocompatible Ordered Iron Oxide Nanopillars for the Observation of Cell Behavior

In this study we present a novel substrate for the investigation of cell response, behavior and attachment to the surface of iron oxide nanopillars. The material was fabricated using an anodic aluminum oxide template to electroform nanopillars of iron oxide. The lengths of the rods were controlled by the electroforming time and this has a direct influence on the stiffness of the nanopillars. The material surface roughness was analyzed using atomic force microscopy, while the lengths were analyzed using field emission scanning electron microscopy. The surface roughness was found to be not significantly different for various nanopillar lengths used in this study (p < 0.05). The biocompatibility of the substrate was confirmed through culturing of murine neural stem/progenitor KT98 cells. The substrates were sterilized and placed into 24-well cell culture plates then seeded with 1 104 cells and cultured for 48 h. The cultured cells were immunostained after 48 h, and it was revealed that the cultured cells on flat and different length nanopillar arrays had different morphologies. The cells were observed to be more spread on the flat substrate than on the nanopillars. It was also found that the cell adhesion area on the shorter nanopillar substrate was greater than the longer nanopillar substrate. The use of this ferromagnetic substrate, due to the metallic iron, to physically stimulate cell cultures and induce differentiation without the addition of chemical growth factors is a future possibility.