A method for increasing permeability of a cellular layer of epithelial cells includes contacting the cellular layer with a nanostructured surface including a plurality of first nanostructures arranged thereon and projecting outward therefrom. A fractal dimension of the plurality of nanostructures is greater than 1. The permeability of the cellular layer by a compound is increased as compared to the permeability of the cellular layer prior to contact with the surface.