Nanoscale Surface Topography Reshapes Neuronal Growth in Culture

Abstract

Neurons are sensitive to topographical cues provided either by in vivo or in vitro environments on the micrometric scale. We have explored the role of randomly distributed silicon nano-pillars on primary hippocampal neurite elongation and axonal differentiation. We observed that neurons adhere on the upper part of nano-pillars with a typical distance between adhesion points of about 500nm. These neurons produce less neurites, elongate faster, and differentiate an axon earlier than those grown on flat silicon surfaces. Moreover, when confronted to a differential surface topography, neurons specify an axon preferentially onto nano-pillars. As a whole, these results highlight the influence of the physical environment in many aspects of neuronal growth.

Nano-biointerfaces for Detection and Control of Biological Information

“…40 SiO 2 , Si and gold are all biocompatible materials, however, the low affinity of neurons for Au observed in neuronal cross-sections obtained using FIB/SEM 34 could also be found even on the nanopillars. By contrast, SiO 2 and Si are commonly used as materials for neuronal platforms in vitro, 41,44 which corresponds to our nanopillar results. These results demonstrate the possibility of realizing neuronal guidance using nano-pillars made of appropriate materials.…”

Brain cells and neuronal networks: Encounters with controlled microenvironments

“…A slightly different organization of these nanopillars into 10 lm distant, short diagonal rows, formed a discontinuous wall enabling to guide bundles of DRG axons extending on the bottom surface [68]. In the same line, it has been reported by Bugnicourt et al [69] that hippocampal neurons adhere on the upper part of isotropically distributed silicon nanopillars characterized by a 35 nm effective diameter and a height of 700 nm (first neighbor distance: 210 nm) (Fig. 4a).…”

“…Another hypothesis relies on a possible channeling effect provided by topographies. Neurite directional choices were either clearly [70], or indirectly [69] evidenced on pillared surfaces, which might reduce the time required for growth cone decision-making and consequently might trigger a faster elongation rate. In support of this channeling effect hypothesis, a mechanism for accelerated growth based on the integration of signals emanating from non-aligned and aligned filopodia on a grooved surface was proposed [76].…”

Enhancing the Nanomaterial Bio-Interface by Addition of Mesoscale Secondary Features: Crinkling of Carbon Nanotube Films To Create Subcellular Ridges

“…We speculate that neuron polarization and ARTICLE axon formation might be stimulated when filopodia extended from unpolarized hippocampal neurons encounter crinkled CNT ridges of similar scale. 48,49 This could explain why neuron cells cultured on crinkled CNT substrates undergo polarization more rapidly than those grown on smooth CNT surfaces. Our speculation is supported by high-resolution SEM images of neuron cells cultured on CNT-PU-100 (Figure 3e), where the neurites connect to crinkled CNT ridges but not to neighboring flat CNTs.…”