Neuronal-like response of N2a living cells to nanoporous patterns of thin supported anodic alumina.

We report about the response of N2a cells, a mouse neuroblastoma cell line, cultured on inert substrates with controlled porous nanostructure. The substrate surfaces were obtained by anodization and post-fabrication etching of thin aluminum films previously deposited onto glass. The morphology of the adherent cells was assessed by scanning electron microscopy. After fluorescent labelling, confocal microscopy was used to assess both the cell density, by cell nuclei counting, and their growth, by characterizing the neurite extensions in both number and length. By comparing with flat and smooth aluminum oxide, we can conclude that the nanoporous morphology of the anodized aluminum is favorable for cell development, which is probably correlated with the high density of regions with high local curvature. The intermediate pore size in the given range seems unfavorable for the number of cells, while the cell shape and the number of extensions point to a dominating differentiation of the N2a cells in correspondence with a characteristic pore size of 60 nm. These results are promising in view of the application of anodic alumina as a platform for the development of neuronal bioassays based on cell interconnectivity.