Neurons on nanometric topographies: insights into neuronal behaviors in vitro

Abstract

Polyacrylamide gels with different stiffness and glass were employed as substrates to investigate how substrate stiffness affects the cellular stiffness of adherent hepatocellular carcinoma (HCCLM3) and hepatic (L02) cells. The interaction of how cell-substrate stiffness influences cell migration was also explored. An atom force microscope measured the stiffness of HCCLM3 and L02 cells on different substrates. Further, F-actin assembly was analyzed using immunofluorescence and Western blot. Finally, cell-surface expression of integrin β1 was quantified by flow cytometry. The results show that, while both HCCLM3 and L02 cells adjusted their cell stiffness to comply with the stiffness of the substrate they were adhered to, their tuning capabilities were different. HCCLM3 cell stiffness complied when substrate stiffness was between 1.1 and 33.7 kPa, whereas the analogous stiffness for L02 cells occurred at a higher substrate stiffness, 3.6 kPa up to glass. These ranges correlated with F-actin filament assembly and integrin β1 expression. In a migration assay, HCCLM3 cells migrated faster on a relatively soft substrate, while L02 cells migrated faster on substrates that were relatively rigid. These findings indicate that different tuning capabilities of HCCLM3 and L02 cells may influence cell migration velocity on substrates with different stiffness by regulating cy- toskeleton remodeling and integrin β1 expression.

Nanocarbon-Coated Porous Anodic Alumina for Bionic Devices

“…These conclusions are in line with other studies where it is shown that the nano-structured scaffolds augment cell-material interactions at different steps, such as initial attachment, differentiation of neuronal lineage, and neuronal phenotype and length [26,27,28,29,30,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57]. It has also been demonstrated by others that nano-topographical features can act as guidance cues to glia and neuron growth on the surface [27,45,47,50,51,53,54]. Despite the efforts on understanding this phenomenon, the cellular mechanism underlying these enhancements still remains elusive [26,44].…”

The Powerful Functions of Peptide-Based Bioactive Matrices for Regenerative Medicine

“…19 Scaffold design pertaining to control over biological signal presentation, 62 nanostructure 44 and mechanical properties 51 have also been shown to influence neuronal adhesion, differentiation, neurite growth and directional guidance in a culture environment. 29,55 For example, a PA nanofiber scaffold presenting the laminin-derived epitope IKVAV was shown to selectively induce the differentiation of the neural stem cells into neurons (Fig. 6a).…”

Control over Neurite Directionality and Neurite Elongation on Anisotropic Micropillar Arrays

“…[17][18][19][20] Topographical studies on neurite guidance have mainly relied on line-based structures, and although guidance has been found to depend heavily on feature dimensions, cell age, and cell type, [ 21 ] neurites on these substrates generally aligned parallel to and extended along the physically continuous lines, as seen on grooved exhibited particularly high sensitivity to dimensional variations and even detected nanometric differences in topography in vitro. [35][36][37][38][39] The fi nal dimensions of the anisotropic pillar arrays were based on our screening experiments, which indicated that extensive interactions between neurites and micropillars occurred at interpillar distances of 6 µm and less (Figure S1, Supporting Information). [ 33,40 ] Interpillar distances for the fi nal anisotropic pillar arrays were, therefore, designed to be constant at 3 µm on one axis (the "proximal axis"), which was below the experimentally obtained threshold distance of 6 µm to ensure pillar interactions along this direction ( Figure 1 a).…”