1. Department of Biological and Macromolecular Materials; Fraunhofer Institute for Microstructure of Materials and Systems IMWS; Halle 06120 Germany
2. Karlsruhe Institute of Technology; Institute for Applied Materials Computational Materials Science IAM-CMS; 76131 Karlsruhe Germany
3. Department of Chemical and Biomolecular Engineering; University of Tennessee; Knoxville TN 37996 USA
4. Center for Applied Microstructure Diagnostics; Fraunhofer Institute for Microstructure of Materials and Systems IMWS; Halle 06120 Germany
5. Department of Neurosurgery; University of Helsinki and Helsinki University Hospital; Helsinki 00260 Finland