Dr.-Ing. Andreas Körtge

Member of the Research Training Group, 1.02.2011 - 31.01.2014

PhD Defence 18.11.2015

Zum Einfluss der oberflächennahen elektrischen Feldverteilung an nanostrukturierten Biomaterialoberflächen auf das Biosystem

Topic

Influence of nanostructured material surfaces on the behavior of adherent biomolecules

Description

Almost instantly after an implant material is in contact with the surrounding tissue, its surface gets coated with proteins of the extracellular matrix (ECM). Consequently, an adherent cell only senses the presence of this protein monolayer. The understanding of how the adsorption and properties of the ECM-proteins is influenced by the material parameters is a crucial step in understanding and controlling the further processes of cell settling, migration, growth, proliferation and finally the integration of an implant into the body.

The aim of this project is to study semiconductor surfaces with spatially nanostructured charge densities in order to influence the adsorption of the proteins. The varying charge density leads to a locally changing electric surface potential which again influences the electrostatic part of the protein-substrate interaction.

Approach

The focus of the studies is initially on the characterization of the adsorption behavior of the important cell adhesion proteins Fibronectin (FN) and Collagen I. Primarily the investigations are conducted by atomic-force-microscopic methods, namely Kelvin-probe force microscopy (KPFM) for mapping the charge densities, Single-molecule force spectroscopy (SMFS) for studying the conformational state of Fibronectin, and imaging of the adherent biomolecules. Additionally, theoretical simulations based on Finite Elements (COMSOL) are conducted in order to understand the near-surface electric field distribution in detail.

Results

Publications

Journal papers:

  • STAEHLKE, S., KOERTGE, A. and  NEBE, JB., 2015. Intracellular calcium dynamics dependent on defined microtopographical features of titanium. Biomaterials 46. pp. 48-57. DOI:10.1016/j.biomaterials.2014.12.016.
  • NEBE, J.B., FINKE, B., KOERTGE, A., REBL, H. and STAEHLKE, S., 2014. Geometrical Micropillars Combined with Chemical Surface Modifications – Independency of Actin Filament Spatial Distribution in Primary Osteoblasts. Material Science Forum, 783-786, pp.1320-1325.
  • KOERTGE, A., ELTER, P., LANGE, R. and BECK, U., 2013. Simulation of the Electric Field Distribution near a Topographically Nanostructured Titanium-Electrolyte Interface: Influence of the Passivation Layer. Journal of Nanomaterials. 2013, Article ID 820914, DOI:10.1155/2013/820914.
  • KOERTGE, A., STAEHLKE, S., LANGE, R., BIRKHOLZ, M., FRASCHKE, M., SCHULZ, K., NEBE, B. and ELTER, P., 2013. Alignment of MG-63 osteoblasts on fibronectin-coated phosphorous doping lattices in silicon. International Journal of Chemical, Materials Science and Engineering, 7(1), S. 62-65.

Conference papers:

  • KOERTGE, A., LEMBKE, U., LANGE, R., STÄHLKE, S., NEBE, B., NEUMANN, H.-G. and BECK, U., 2011. Surface Analysis of Ti and TiO2 Coatings Made by Gas Flow Sputtering. 24th European Conference on Biomaterials – Annual Conference of the European Society for Biomaterials, Dublin.

Supervisors