BBB Seminar: Alexandre Micoulet
Nano- and micro-systems to study cell mechanics and adhesion
Alexandre Micoulet, Department of Biomedicine, University of Bergen
In a tissue, a cell integrates various signals from its micro-environment and generates the corresponding cell-specific response. The spectrum of cell response is broad and includes for example switch between cell proliferation and differentiation, matrix generation and degradation, and cell migration. Abnormal signals occur in the case of diseases and tumour formation (during the stromal response).
Micro-environmental signals can be as diverse as cell spatial confinement, forces (generated by other cells or resulting from matrix mechanical properties), specific activation of cell-adhesion membrane receptors, such as integrins, by matrix ligands locally present, soluble signalling molecules, etc. Consequently, in order to understand cell response, one approach is to design properties of the micro-environment and then make observations on induced cell response. The fabrication of an artificial micro-environment for a cell requires fabrication at microscale e.g. to confine a cell or to apply forces to it, and at nanoscale e.g. to control quantity and spatial distribution of a specific ligand such as a peptide or a protein.
First, techniques of nano- and micro-fabrication will be described and devices available in the new NanoLab in the Department will be presented. Second, in order to illustrate the scientific breakthroughs that these kind of approaches may lead to, a couple of studies will be discussed, i.e. studies using micro-systems, such as the characterisation of cell mechanical properties by measurement of stress-strain curves of a single cell and the spreading of cells on micro-patterned areas, and studies using nano-systems, such as the spreading of fibroblasts on bio-functionalised nanopatterned surfaces and the measurement of cell-adhesion forces to the same surfaces by atomic force microscopy.
Hans-Hermann Gerdes, Dept. of Biomedicine