Nano-Scale Surface Topology Improves Neuronal Development in Culture

GHISLAIN BUGNICOURT, JACQUES BROCARD, MARIANO BISBAL, NORA COLLOMB, ANNIE SCHWEITZER, CATHERINE VILLARD.

Baltimore, M

Congreso; 55th Annual Meeting of the Biophysical-Society; 2011

Biophyscal Society

Neurons may be grown on opaque silicon surfaces covered with poly-L-lysine,the same way it is usually carried out on glass coverslips. Neuronal development may also be improved by structuring silicon surfaces with reactive ion etching. Here, we produced silicon samples by a classical photolithography process with an alternation of 1mm-wide bands, presenting atomically flat or rough topologies.Hippocampal neurons from E18.5 mice, grown over these samples, developedfaster on rough bands: they differentiated an axon more readily after 2 days inculture (75% neurons display an axon vs 60% on flat surfaces) and their totalneuritic length was 50% larger whereas they developed 20% less neurites.Moreover, neurons with neurites in both areas preferentially differentiated anaxon onto the rough surface (76% polarized neurons).Finally, we characterized the topology of rough surfaces using  Scanning ElectronMicroscopy. We observed 1mm-high silicon nano-peaks randomly distributed onthe  surface.  Interestingly,  our  observations indicated that neurites grew on topof the nano-peaks with a typical distance between    adhesion    points    of    about600nm. Neuron on rough silicon surface (bar,  5  mm),  and  zoom  over  a  neurite(dark rectangle and inset; bar, 500 nm).