Research focus

Cellular functions on the nanoscale

 

Cells are surrounded by a complex network of polysaccharides and protein nanofibres, the extracellular matrix (ECM). This nanostructured composite material provides mechanical support in tissues and plays an important role in cell adhesion and signalling on the nanoscale.

Our interdisciplinary team works on the development of nanostructured biomaterials, which can mimic different features of the native extracellular environment. We want to understand and control cellular interactions on the nanoscale using novel synthetic biomaterials.

Towards this aim, we combine principles from synthetic biology and nanotechnology with biophysical methods and cell biology studies. Common techniques being used in our lab include, for instance, scanning electron microscopy, fluorescence microscopy, 3D-printing and cell culture analysis.

 

 

Synthetic extracellular matrices

 

One research focus of our interdisciplinary group is on synthetic ECM systems from protein and polysaccharide nanofibres. We have developed a novel extrusion approach through alumina nanopores to prepare synthetic ECM scaffolds from various biopolymer nanofibres. The morphology and nanotopography of these nanofibre assemblies is analysed with electron microscopy. We explore how the composition of such novel protein composites can be adjusted on the nanoscale and how the hierarchical fibre assembly can be controlled on a microscopic level. The biological functionality of our extruded nanofibres is studied in cell culture test systems and molecular binding experiments. With these synthetic ECM scaffolds we aim at a precise control of cellular interactions, which we monitor with fluorescence microscopy.  

 

 

Raoufi, M., Aslankoohi, N., Mollenhauer, C., Boehm, H., Spatz, J.P., Brüggemann, D.: Template-assisted extrusion of biopolymer nanofibers under physiological conditions, Integrative Biology 2016, 8, 1059-1066

Protein fibrillogenesis

 

Our extrusion method also has a lasting influence on the protein conformation of extruded nanofibres. We analyse these structural changes with Förster resonance energy transfer (FRET) measurements and circular dichroism spectroscopy. It is our aim to establish extruded protein nanofibres as a model system for protein fibrillogenesis in a cell-free environment. Therefore, we explore how structural changes in extruded nanofibres are affected by external factors like varying buffer conditions. Further on, we want to understand how such tailored conformational changes in nanofibrous biomaterials can be used to control the manifold interactions with cells.

 

 

 

Raoufi, M., Das, T., Schoen, I., Vogel, V., Brüggemann, D., Spatz, J.P.: Nanopore diameters tune strain in extruded fibronectin fibers, Nano Letters 2015, 15, 6357-6364

Nanoporous aluminium oxide

 

We are also interested in the biological functionality of other nanostructured biomaterials, such as nanoporous aluminium oxide. Alumina membranes are prepared in an electrochemical anodisation process, which results in the self-assembly of vertical nanopores with well-controllable geometries. We study the interaction of these nanoporous membranes with various proteins and cell cultures. Further on, we develop different functionalisation methods to tailor the surface properties of these nanomaterials for cell culture studies and the extrusion of biopolymer nanofibres.

 

 

Brüggemann, D.: Nanoporous aluminium oxide membranes as cell interfaces, Journal of Nanomaterials 2013, 1-18