Local surface modification via confined electrochemical deposition with FluidFM †

International audienceWe show how the association of AFM with microfluidics, namely FluidFM, is a valuable approach for the versatile electrochemical creation of patterns having diverse shapes and topologies. Localization of the electrochemical reactions was obtained by confining the electroactive species in the microchannel and dispensing them at a precise position through the aperture of FluidFM probes. The force feedback enabled a gentle approach onto the electrode as well as a gentle contact during both the lithography procedure as well as in situ topographical AFM imaging just before or after deposition. As model systems, we demonstrate electroplating of copper and electrografting of organic moieties by reduction of aryldiazonium salts

Mechanical force induces mitochondrial fission.

Eukaryotic cells are densely packed with macromolecular complexes and intertwining organelles, continually transported and reshaped. Intriguingly, organelles avoid clashing and entangling with each other in such limited space. Mitochondria form extensive networks constantly remodeled by fission and fusion. Here, we show that mitochondrial fission is triggered by mechanical forces. Mechano-stimulation of mitochondria - via encounter with motile intracellular pathogens, via external pressure applied by an atomic force microscope, or via cell migration across uneven microsurfaces - results in the recruitment of the mitochondrial fission machinery, and subsequent division. We propose that MFF, owing to affinity for narrow mitochondria, acts as a membrane-bound force sensor to recruit the fission machinery to mechanically strained sites. Thus, mitochondria adapt to the environment by sensing and responding to biomechanical cues. Our findings that mechanical triggers can be coupled to biochemical responses in membrane dynamics may explain how organelles orderly cohabit in the crowded cytoplasm

Local surface modification via confined electrochemical deposition with FluidFM

We show how the association of AFM with microfluidics, namely FluidFM, is a valuable approach for the versatile electrochemical creation of patterns having diverse shapes and topologies. Localization of the electrochemical reactions was obtained by confining the electroactive species in the microchannel and dispensing them at a precise position through the aperture of FluidFM probes. The force feedback enabled a gentle approach onto the electrode as well as a gentle contact during both the lithography procedure as well as in situ topographical AFM imaging just before or after deposition. As model systems, we demonstrate electroplating of copper and electrografting of organic moieties by reduction of aryldiazonium salts

Mechanical force induces mitochondrial fission

Eukaryotic cells are densely packed with macromolecular complexes and intertwining organelles, continually transported and reshaped. Intriguingly, organelles avoid clashing and entangling with each other in such limited space. Mitochondria form extensive networks constantly remodeled by fission and fusion. Here, we show that mitochondrial fission is triggered by mechanical forces. Mechano-stimulation of mitochondria - via encounter with motile intracellular pathogens, via external pressure applied by an atomic force microscope, or via cell migration across uneven microsurfaces - results in the recruitment of the mitochondrial fission machinery, and subsequent division. We propose that MFF, owing to affinity for narrow mitochondria, acts as a membrane-bound force sensor to recruit the fission machinery to mechanically strained sites. Thus, mitochondria adapt to the environment by sensing and responding to biomechanical cues. Our findings that mechanical triggers can be coupled to biochemical responses in membrane dynamics may explain how organelles orderly cohabit in the crowded cytoplasm