Biological Adhesion on Nanopatterned Substrates Studied with Force Spectroscopy and Microinterferometry

For a physical understanding of adhesion, surfaces of defined adhesion properties are required. In this work, biofunctional nanopatterns were employed, which allow molecules to be positioned in a quasi-hexagonal lattice. For such an arrangement of streptavidin molecules the surface energy was analysed microinterferometrically. Furthermore, nanopatterns were used to investigate integrin-mediated cell adhesion, which is a highly complex biological process and essential for numerous cell functions. With nanopatterns the distance between adjacent single integrin binding sites is precisely defined. Recent cell culture experiments have revealed that this distance strongly affects cell adhesion, especially the formation of adhesion clusters, known as focal contacts. To quantify the adhesion cluster formation for different integrin binding site spacings, cell adhesion was studied at different timescales using magnetic tweezers and atomic force microscopy (AFM). The experiments demonstrated that an integrin binding site spacing of 70 nm and more prevents the cooperative formation of early adhesion clusters in initial adhesion. In long-term adhesion studies, after several hours of cell adhesion, it turned out that focal contact formation cooperatively increases the local adhesion strength. The obtained results could be related to theoretical models and make an important contribution to the physical understanding of cell adhesion.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2006

Author dc:creator

• Selhuber, Christine

Contributors dc:contributor

• Spatz, Joachim

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/7021

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:7021