E2.2: Nanostructured Templates with Specific Adhesive Properties
Subprojekt Leaders:
Doris Wedlich
Zoologisches Institut, KIT
Hartmut Gliemann
Institut für Funktionelle Grenzflächen, KIT
Contributing Scientists:
Present: Dagmar Fichtner, Ming-Tao Lee
Past: Sinem Engin, Andre Petershans, Claudia Winter
During the recent years the cellular microenvironment has become of growing interest in the stem cell research. Stem cells are characterized by their ability to self-renew and to differentiate into a broad set of specialized cell types. Specific properties of the cellular microenvironment control maintenance of the stem cell fate while others promote stem cell differentiation. Specific cell adhesion molecules of the cadherin-superfamily play crucial roles in both processes.
We aim to reproduce specific microenvironments by immobilization of adhesion molecules on 2D and 3D structured inanimate material. We use UV-lithography, DipPen Lithography, Microcontact-printing for surface structuring and advanced the SNAP-tag Benzyl-guanine reaction to immobilize adhesion molecules on surfaces and nanodots.
Using UV-light lithography for specific stem cell adhesion on polymer patterns
By the irradiation of polymer surfaces with UV-light the physical, chemical and biological surface properties are changed. In the case of conventional optical lithographic techniques, which are based on a light induced chemical modification of the surface, the different chemical behavior of the irradiated sample areas compared to that of the non-irradiated surface areas was used to immobilize gelatin site selectively for stem cell adhesion. The lateral and vertical dimensions of the structure can be controlled merely by the irradiation dose. The structures are chemically functionalised during the irradiation so that structure formation and chemical functionalisation are both achieved in one step without further processing.
SNAP-tag based covalently binding of proteins on surfaces
The bottleneck in surface functionalisation is the lack of smart linker molecules that provide an orientated immobilization of proteins. Another drawback is the lack of biologically inert surface materials, a prerequisite for specific ligand localization. To overcome these disadvantages we develop strategies for non-covalent and covalent binding of His- or Snap-tagged proteins. For this purpose we generate Self-Assembled-Monolayers (SAMs) composed out of EG4-thiols and thiols with Benzylgunanine head-groups to which extracellular domains of cadherins C-terminally fused to a SNAP-tag are coupled. In combination with µCP we create different adhesive surface patterns. Cells expressing the corresponding cadherin recognize the patterns and adapt their shape to gain optimal binding.
Publications
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[1] |
A. Petershans, D. Wedlich, and L. Fruk, Bioconjugation of CdSe/ZnS Nanoparticles with SNAP tagged proteins, Chem Comm in press (2011) |
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[2] |
S. Engin, V. Trouillet, C.M. Franz, A. Welle, M. Bruns, and D. Wedlich, Benzylguanine thiol self-assembled monolayers for the immobilization of SNAP-tag proteins on microcontact-printed surface structures, Langmuir 26, 6097 (2010) |
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[3] |
S. Montero-Pancera, V. Trouillet, M. Bruns, Th. Schimmel, P.G. Weidler, A. Petershans, D. Fichtner, A. Lyapin, S. Reichlmaier, D. Wedlich, and H. Gliemann, Design of Chemically Activated Microwells by One-Step UV- Lithography for Stem Cell Adhesion, Langmuir 26, 2050 (2010) |
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[4] |
A. Petershans, A. Lypapin, S. Reichlmaier, S. Kalinina, D.Wedlich and H.Gliemann, TOF-SIMS analysis of structured surfaces biofunctionalized by one-step coupling of a spacer-linked GRGDS peptide, J. Coll Interface Sci. 342, 30 (2010) |
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[5] |
S. Kalinina, H. Gliemann, M. López-García, A. Petershans, J. Auernheimer, Th. Schimmel, M. Bruns, A. Schambony, H. Kessler, and D. Wedlich, Isothiocyanate-functionalized RGD-peptides for tailoring cell-adhesive surface patterns, Biomaterials 29, 3004 (2008) |
List of Publications 2006-2011 as PDF
Subproject Report 2006-2010 as PDF