Micropatterned hydrogenated amorphous carbon guides mesenchymal stem cells towards neuronal differentiation

This study investigated how the design of surface topography may stimulate stem cell differentiation towards a neural lineage. To this end, hydrogenated amorphous carbon (a-C:H) groove topographies with width/spacing ridges ranging from 80/40μm, 40/30μm and 30/20μm and depth of 24 nm were used as a single mechanotransducer stimulus to generate neural cells from human bone marrow mesenchymal stem cells (hBM-MSCs) in vitro. As comparative experiments, soluble brain-derived neurotrophic factor (BDNF) was used as additional biochemical inducer agent. Despite simultaneous presence of a-C:H micropatterned nanoridges and soluble BDNF resulted in the highest percentage of neuronal-like differentiated cells our findings demonstrate that the surface topography with micropatterned nanoridge width/spacing of 40/30μm (single stimulus) induced hBM-MSCs to acquire neuronal characteristics in the absence of differentiating agents. On the other hand, the alternative a-C:H ridge dimensions tested failed to induce stem cell differentiation towards neuronal properties, thereby suggesting the occurrence of a mechanotransducer effect exerted by optimal nano/microstructure dimensions on the hBM-MSCs responses.