Conversion of nanoscale topographical information of cluster-assembled zirconia surfaces into mechanotransductive events promotes neuronal differentiation

Additional file 4: Table S1. Proteomic data for upregulated proteins. Proteins upregulated (compared to flat-Zr) or present only in cells grown on ns-Zr15. Adhesome proteins and proteins with roles in mechanobiological processes are marked in dark and light grey, respectively

Nanoconfinement of Ionic Liquid into Porous Carbon Electrodes

International audiencePlanar electrochemical double-layer capacitors (supercapacitors) are strategic elements for the realization of miniaturized autonomous devices requiring energy storage and conversion capabilities. In particular, supercapacitors fabricated with nanoporous carbon electrodes and ionic liquids as electrolytes are very promising for a wide range of applications. The understanding and control of the interactions of the ionic liquid with the porous carbon interface is both practically and fundamentally interesting, because of the effects of surface confinement on the structural and functional properties of the ionic liquid. In particular, the role of the morphology in the ionic liquid confinement has attracted huge interest in many disciplines. Here we report direct experimental evidence of the solid-like structuring of confined 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([Bmim][NTf2]), which extends several tens of nanometers from the interface of nanoporous carbon thin films. These solid-like structures coexist with a huge amount of ionic liquid in its bulk phase. The presence of a solid-like phase occurring at the interface affects the double-layer organization of the ionic liquid at the electrified interface of nanoporous carbon based planar supercapacitors. Our results suggest the presence of the solid-like structured ionic liquid domains not only on the upper carbon thin film interface but also into the bulk of the nanoporous matrix

Cluster-Assembled Zirconia Substrates Accelerate the Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

International audienceDue to their high mechanical strength and good biocompatibility, nanostructured zirconia surfaces (ns-ZrOx) are widely used for bio-applications. Through supersonic cluster beam deposition, we produced ZrOx films with controllable roughness at the nanoscale, mimicking the morphological and topographical properties of the extracellular matrix. We show that a 20 nm ns-ZrOx surface accelerates the osteogenic differentiation of human bone marrow-derived MSCs (bMSCs) by increasing the deposition of calcium in the extracellular matrix and upregulating some osteogenic differentiation markers. bMSCs seeded on 20 nm ns-ZrOx show randomly oriented actin fibers, changes in nuclear morphology, and a reduction in mitochondrial transmembrane potential when compared to the cells cultured on flat zirconia (flat-ZrO2) substrates and glass coverslips used as controls. Additionally, an increase in ROS, known to promote osteogenesis, was detected after 24 h of culture on 20 nm ns-ZrOx. All the modifications induced by the ns-ZrOx surface are rescued after the first hours of culture. We propose that ns-ZrOx-induced cytoskeletal remodeling transmits signals generated by the extracellular environment to the nucleus, with the consequent modulation of the expression of genes controlling cell fate

The glycocalyx affects the mechanotransductive perception of the topographical microenvironment

Abstract The cell/microenvironment interface is the starting point of integrin-mediated mechanotransduction, but many details of mechanotransductive signal integration remain elusive due to the complexity of the involved (extra)cellular structures, such as the glycocalyx. We used nano-bio-interfaces reproducing the complex nanotopographical features of the extracellular matrix to analyse the glycocalyx impact on PC12 cell mechanosensing at the nanoscale (e.g., by force spectroscopy with functionalised probes). Our data demonstrates that the glycocalyx configuration affects spatio-temporal nanotopography-sensitive mechanotransductive events at the cell/microenvironment interface. Opposing effects of major glycocalyx removal were observed, when comparing flat and specific nanotopographical conditions. The excessive retrograde actin flow speed and force loading are strongly reduced on certain nanotopographies upon strong reduction of the native glycocalyx, while on the flat substrate we observe the opposite trend. Our results highlight the importance of the glycocalyx configuration in a molecular clutch force loading-dependent cellular mechanism for mechanosensing of microenvironmental nanotopographical features