Force of Nature: mimicking mechanoscape to control stem cell fate

Speaker : Dr Yu Suk Choi – University of Western Australia

Venue    : Fri 10 June 2016, 12 noon (Murdoch University, McCusker Conference Center)

 

Stem cells rely on, and are finely tuned to respond to, their immediate microenvironment, which can be exceedingly complex. Biomaterials must present cells with finely tuned mechanical cues to systematically examine their control over development or pathological insults. Chief among these mechanical cues is extracellular matrix (ECM) stiffness which is perhaps intuitive; functional boundaries between tissues such neuromuscular junctions or phathological boundaries, e.g. the infarcted fibrous heart tissue juxtaposed with healthy myocardium, are prevalent in vivo and imply that mechanical cues not only help guide differentiation/regeneration but may regulate disease mechanisms. In tissue engineering and regenerative medicine, it has become essential to understand and consider the biomechanics in cell-ECM interaction to better design biomaterials and to regenerate cells and/or tissues. In this talk, I will introduce how stiffness affects stem cells via mechanotransduction and the state-of-the-art materials technologies (atomic force microscopy, traction force microscopy, and smart material fabrication) used to mimic stiffness of the microenvironment.

Dr. Choi is a lecturer in the School of Anatomy Physiology and Human Biology at the University of Western Australia. His research focus is on stem cell – extracellular matrix mechanical interaction using multi-disciplinary approaches based on previous training in various fields including PhD in stem cell/tissue engineering (University of Melbourne 2006-2010), Postdoc in Bioengineering (UCSD 2010-2013), and Research Fellow in Cardiology (University of Sydney, 2013-2015). Yu have 20 research publications in top Journals including Nature Materials and Advanced Functional Materials. He has attracted 8 research grants totaling over $1.3 million including NHMRC Project Grant (CIA) since 2012.

Neuro-Muscular Modelling of Gait Biomechanics

Speaker : Prof David Lloyd – Griffith University

Venue    : Thu 26 May 2016, 3pm (Murdoch University, Senate Room)

David is the Director of the Musculoskeletal Research Program at the Griffith Health Institute at the Gold Coast campus of Griffith University in Queensland. In lieu of an abstract, here’s some information about David’s expertise and research directions, copied from his web site:

Research expertise

• Neuromuscular Skeletal Computational Modelling
• Muscular skeletal injuries of the lower limb
• Osteoarthritis of the lower limb joints
• Tissue engineering treatment of tendinopathy and cartilage
• Training to prevent muscular skeletal injuries and disease

 

 

Modelling hydrogen clearance from a rat retina

Speaker : Dr Duncan Farrow – Murdoch University

Venue    : Thu 16 Jun 2016, 4pm (Murdoch University, ECL2.031)

 

Blood flow in biological tissue can be studied by measuring the clearance of an injected inert solution such as hydrogen saturated saline. Studying clearance in the eye is complicated by the vascular structure varying signicantly through the choroid and retina. The majority of the blood flow is in the choroid but hydrogen diffuses into the retina complicating the measured clearance response. This talk will present two models of hydrogen clearance. The results of these models will be compared with laboratory measurements of hydrogen clearance in a rat retina.

 

Image sources: Feature image extracted from https://en.wikipedia.org/wiki/Macula_of_retina, where it is reproduced from Häggström, Mikael. “Medical gallery of Mikael Häggström 2014“. Wikiversity Journal of Medicine 1 (2). DOI:10.15347/wjm/2014.008. Graphics above reproduced from Science of DME

Dance to the Vibrations – Motion of Active Granular Rotors

Speaker: Dr Christian Scholz –  Friedrich-Alexander University Erlangen-Nuremberg

Venue   : Thu 8 Sept 2016 – 4pm (Murdoch University, venue tba)

The majority of animal life performs active motion, i.e. organisms store energy within internal degrees of freedom and later release it in terms of directed motion. While in biological organisms this topic itself has been studied extensively, from swimming bacteria to flocks of animals, interest grew also in physical systems of inanimate objects that perform active motion. Most noticeable artificial microswimmers, but also active granular walkers.

Many studies consider translational active motion, but it has been shown that also rotational active motion leads to interesting novel effects in many-particle systems. In simulations of actively rotating spinners, a counter-intuitive separation of particles into patches of equal sense of rotation has been observed.

We use a particle design established in to experimentally create a system of 3D-printed active rotors, driven by vertical vibrations. Our experiments confirm the numerical observation of a phase separated stationary state. The evolution of the patterns from the mixed initial state can be quantified from the size of the clusters from the Voronoi triangulation or the length of the interface between patches, by counting Delaunay bonds between particles of opposite sense of rotation. The particle motion can be mapped onto a Langevin equation, which allows a direct comparison between experiment and simulation.