CeNS Colloquium

Prof. Joachim Spatz
MPI for Metals Research & University of Heidelberg

Designing of cellular environments has become a valuable tool for guiding cellular activity such as differentiation, spreading, motility, proliferation or apoptosis which altogether regulates tissue development in a complex manner. The adhesion of cells to its environment is involved in most cellular decision in vivo and in vitro. Its detailed understanding and defined control opens new strategies for medical technologies with respect to, e.g., stem cell regulation, tissue scaffolds, cell selection due to their disease state, artificial blood vessels, or immunology. Our approach to design cellular environments is based on self-organizing spatial positioning of single signaling molecules attached to inorganic or polymeric supports, which offers highest spatial resolution with respect to the position of single transmembrane receptor activation. This approach enables the tuning of cellular material with respect to its most relevant properties, i.e., viscoelasticity, peptide composition, nanotopography and spatial nanopatterning of signaling molecule. These materials represent nano-digital materials since they enable the counting of individual signaling molecules in contact with the cell membrane, separated by a biologically inert background. Within these materials, the regulation of cellular responses is based on a biologically inert background which does not trigger any cell activation, which is then patterned with specific signaling molecules such as peptide ligands in well defined nanoscopic geometries. This approach enables the testing of cellular responses to individual, specific signaling molecules and their spatial ordering. Detailed consideration is also given to the fact that protein clusters such as those found at focal adhesion sites represent, to a large extent, hierarchically-organized cooperativity among various proteins. Moreover, nano-digital supports such as those described herein are clearly capable of involvement in such dynamic cellular processes as protein ordering at the cells periphery which in turn leads to programming cell responses.