They show that rat cortical neurons cultured on the gold nanocone surfaces exhibit higher survival rate and accelerated neurite outgrowth compared to that on the planar glass substrate.
The morphological changes of neurons were maximized on the nanocone structures fabricated with 1 µm polystyrene beads, with two times longer neurite than that on the glass coverslip in average.
According to the scientists, the detailed observation of the cell/nanocone interface suggests that the gold nanocone arrays provide a surface topography which is similar to the structure of filopodia and dendrite with reasonable contacting area for cell attachment, in addition to the periodicity of the structure to induce the mechanical tension to the neurite, which may be the key factors of the scaffold for the acceleration of the neurite outgrowth.
The researchers conclude that their nanocone array substrates may hold great potentials for the new design of the neuronal interface with 3D nanostructures by following three aspects which are important for the device applications:
First, the structures can be created by a simple and cheap fabrication process without using clean room facilities, and the geometry of nanocones including the pitch and the height is easily controllable.
Second, the Teflon films used as the substrate are flexible and hold antifouling properties. They can be used for enhancing the adhesion of neuronal cells and formation of their networks in the selected area on the device.
Finally, the deposition of gold films allows the substrate to be conductive and to hold unique optical properties supported by surface plasmons, which are crucial for electrophysiological and optical measurements as well as inducing the electric or optical stimuli to the attached cells.