2nd of April 2015, Chichley Hall
Patrick McGarry integrates modelling with engineering based analysis of, and experimentation on cells. Starting off with cells embedded in gels and how they respond differentially by turning in the line or perpendicular to cyclic strain applied he extended on the model developed by Bob Meeking & Vikram Deshpande. He moved on to describe how cells could be squashed in a defined way using an atomic force microscope, where the cantilever had a large glass bead attached. By indentation at less than 10% he could analyse how the cells responded, by applying the deformation in a defined way the viscous and elastic aspects of the cells mechanical properties are separated. Applying the reactive contractile fibre (F-actin + myosin) model developed earlier he predicted that the cells would respond by assembling top-bottom fibres to counteract the imposed extension. When the cells were squashed hoop fibres would assemble to explain the resilience observed. By shearing attached chondrocytes the cell cohesion and attachment were tested, and modelled. By applying suction on a pipette the mechanical properties of cells can be tested, by imaging from the side the group was able to correlate the extension of the attached cells int the pipette with the suction applied. In order to investigate how the different aspects of the cytoskeleton interplayed to define the cells overall resilience to the suction, different poisons were applied. The predictions derived using their model the data showed that the nucleus is a hyperelastic medium. An isotropic, hyperelastic model was applied to investigate how the development of the heart tube to the cardiac muscle results in the distinct layering with the different orientations of fibres that can consistently be observed.
More on Patrick McGarry http://ncbes.nuigalway.ie/bio/pat-mc-garry.aspx
This talk was part of a workshop on "Cell Mechanobiology" organised by Rene de Borst, which took place April 1st and 2nd 2015, with support by the Royal Society at Chicheley Hall. for the programme details see: http://bio-mat-sketches-mor.blogspot.co.uk/2015/04/cell-mechanobiology-workshop-1st-2nd.html