Biological systems are multiscale, hierarchically constructed from nanometre sized proteins and DNA to micron-cells and cm tissues and organs; mechanics is one of the fundamental mechanisms that link all the scales and underpins biological development and adaptation, transmission of information and transport. Mechanics and mechanical properties are therefore fundamental for the design of materials with medical applications, for example the mechanics of liposomes for the targeted delivery of specific places such as tumours, or in the materials used in tissue engineering in regenerative medicine.
In my lab we develop methods to measure the mechanical properties of key biological structures such as cell membranes, extracellular matrix components, cells and tissues. We have developed techniques based on the atomic force microscope (AFM) that have enabled us to quantified the stiffness e.g. of a single membrane protein (1) or a lipid bilayer (2). Using multifrequency AFM techniques we have been able to quantitatively map the viscoelastic properties of membranes (3) and living cells with unprecedented speed and accuracy (4) in cultures and in tissues of living plants, which is enabling us to link the nanoscale properties to micron mechanical properties of cells and their role in growth (5). In parallel we are designing biocompatible biomimetic magnetic nanocomposites that are able to measure and steer biological function using forces and mechanics in tissue engineering .
(1) Voitchovsky et al. Differential stiffness and lipid mobility in the leaflets of purple membranes Biophysical Journal, 90 (6), 2075-2085 (2006).
(2) Zhou, Liang and Contera . Effect of intra-membrane C60 fullerenes on the modulus of elasticity and the mechanical resistance of gel and fluid lipid bilayers. Nanoscale. Oct 28;7(40):17102-8 (2015); Dohno, Makishi, Nakatani, Contera, Amphiphilic DNA tiles for controlled insertion and 2D assembly on fluid lipid membranes: the effect on mechanical properties Nanoscale 9, 3051-3058 (2017).
(3) Al Rekabi, Contera , in preparation
(4) Raman, et al. Mapping nanomechanical properties of live cells using multi-harmonic atomic force microscopy, Nature Nanotechnology 6 (2011) 809-814.
(5) J Seifert, I Moore and S Contera (2017) in preparation