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AG Surface Biofunctionalization

Surface Biofunctionalization 

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Our topic is the generation of geometrically tailored and biologically active surfaces by combing different techniques developed in chemistry, physics and molecular biology. The project is part of the DFG-Center for Functional Nanostructures. The aim of this project is the development of two- and three-dimensional nanostructured biological interfaces in order to understand the biology and physics of cell adhesion, cell signaling, growth and differentiation in response to a defined cellular microenvironment.

The results of this investigation will provide basic understanding of cell adhesion and migration and in a long run, they can be used in tissue engineering to manipulate and direct cell adhesion, growth and differentiation.

Different patterns of E-cadherin coated surfaces (red: immunostaining with anti E-cadherin, black: non-functionalized areas)
For the production of artificial and biologically active surfaces we mainly use the method of micro contact printing- and etching. Currently, amino or thiol group containing linker molecules are used for protein conjugation to Au or SiO2 surfaces.

To mimic cell-substrate and cell-cell adhesion we use two different compounds:
1. Chemically synthesized RGD-peptides present in many extracellular matrix proteins which are recognized by integrin receptors
2. Extracellular domains of cadherins which are synthesized in eucaryotic expression systems and purified by affinity chromatography
Fig. 2

The peptides are coupled directly to the surface by a chemical reaction. For protein coating we fuse the target proteins to different tag systems which bind to their substrate with high affinity. These specific substrates are coupled to the surfaces, e.g. via thiols on gold. and therefore act as a linker between inorganic and biological phases. Applied tags are the Strep tag, the SNAP tag and the His6 tag, the latter one is also used for affinity chromatography. For the purification of recombinant proteins common protocols for liquid chromatography are used.

Fig. 3 Fig. 4 left: RGD-functionalized (black) and non-functionalized (grey) areas of a micropatterned surface.

right: Cells attached to the RGD-peptide coated areas between non-functionalized bands, which are avoided by cells. Specific staining shows P-paxilin (red), actin (green) and the nucleus (blue).

After cell cultivation on these structured surfaces the activity of signalling pathways (e.g. Wnt, BMP, Ras) important for cell proliferation and differentiation as well as cell transformation will be analysed.



Formerly Staff 

Dr. Dagmar Fichtner
Claudia Winter, technician
Dr. Jubin Kashef
Dr. Sinem Engin
Dr. Sviatlana V. Kalinina
 



 
 

Collaborators 

 • Dr. Hartmut Gliemann Institut für Technische Chemie FZK
 • Prof. Thomas Schimmel Institut für Nanotechnologie FZK