Effect of aerogel’s topography and surface roughness on neurite extension in the presence and absence of applied DC bias.

Aerogels have been studied for their biomedical applications including drug delivery, regenerative medicine, wound healing, and biosensing. Previous work from this group has shown the suitability of aerogels as neuronal scaffolds. Aerogel’s inherent 3-D structure offers an advantage over other biocompatible substrates that lack the dimensionality needed to mimic the in vitro topography of tissues. It has also been shown that cell behavior is strongly influenced by external factors including the surface topography, stiffness, and electric fields. Here, the authors studied these effects by using aerogels as scaffolds for PC-12 cells, a neuronal analogue. Surface roughness ranged from 0 to 3 μm and stiffness 10 kPa – 4 MPa. Applied DC bias was investigated in both conductive and insulating aerogel types. This investigation reveals what the optimal substrate features for neurite extension are and the significance of these findings to optimize materials for nerve repair is discussed.