Complex flow of biomaterials

The interplay between structure and transport is complex, particularly when the structure is soft and deformable as is typically the case in most biological systems. A multidisciplinary approach is a prerequisite to elucidate this complex problem. In the past, we developed home-built set-ups to investigate the structural-mechanical relation in situ – either with ultra-fast confocal, microscopy or with Small Angle X-ray and neutron scattering- of well-controlled complex systems, making use of the toolbox of biological building blocks. The information acquired at single-particle and ensemble levels facilitated direct comparison with theory and computer simulations, resolving issues such as shear-thinning rod dispersions. 

Currently, we are applying these concepts to two real-life systems: blood flow through the brain vasculature and extracellular matrices. Both systems are instrumental to bio-information processing. Blood supplies the brain with oxygen, nutrients and molecular messengers while cooling it simultaneously. In order to understand the flow through this network the complexity of blood as well as the network geometry needs to be taken into account. We are investigating the flow by mimicking the brain vasculature, as obtained from the Human Brain Project, in 3D microfluidic glass channels produced by the novel scanning laser etching technique, whilst tuning the aggregation of red blood cells. Using this palette of tools, we aim to elucidate flow behaviour, comprehend cooling and messaging, and programme flaws and their consequences. The interplay between extracellular matrices and cells determines the cell fate and function. As extracellular matrices mostly consist of stiff fibrillar structures, we apply our knowledge of the mechanical response of such systems to control alignment and stiffness, investigating the response of embedded cells. Our ultimate goal is to develop aligned cell networks that mimic the brain and study signal transduction through these networks.