Dr. Ralf Richter "Biological hydrogels - from supramolecular organization and dynamics to biological function"
CIC biomaGUNE, Biosurfaces Unit Parque Tecnológico de San Sebastian, Spain
What |
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When |
Jan 14, 2015 from 02:15 PM to 03:00 PM |
Where | Seminarraum A, FMF, Stefan-Meier-Str. 21, Freiburg |
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Nature has evolved complex materials that are exquisitely designed to perform specific functions. Certain proteins and glycans self-organize in vivo into soft and dynamic, strongly hydrated gel-like matrices. Illustrative examples of such biological hydrogels are peri- and extracellular matrices. Even though biological hydrogels are ubiquitous in living organisms and fulfill fundamental biological tasks, we have today a very limited understanding of their internal organization, and how they function. The main reason is that this type of assemblies is difficult to study with conventional biochemical methods.
In order to study biological hydrogels directly on the supramolecular level, we have developed an unconventional approach that draws on knowledge from several scientific disciplines. Exploiting surface science tools, we tailor-make model systems by directed self-assembly of purified components on solid supports. With a toolbox of biophysical characterization techniques, including QCM-D, ellipsometry, AFM and RICM, these model systems can be investigated quantitatively and in great detail. The experimental data, combined with soft matter physics theory, allow us to develop a better understanding of the relationship between the supramolecular organization and dynamics of biological hydrogels, their physico-chemical properties and their biological function. To illustrate this concept, I will present a few examples, including recent works on the cross-linking of glyosaminoglycan-rich extracellular matrices (such as the jelly-like matrix around the mammalian egg that is crucial for fertility), on the nuclear pore permeability barrier (that makes nucleo-cytoplasmic transport selective), and on “superselective” targeting of the cell surface with flexible polymers.