1. Institute of Radiopharmaceutical Cancer Research Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstrasse 400 01328 Dresden Germany
2. Department of Biological Models Institute of Macromolecular Chemistry Heyrovsky Square 2 16206 Prague Czech Republic
3. Supramolecular Polymer Systems Institute of Macromolecular Chemistry Heyrovsky Square 2 16206 Prague Czech Republic
4. Department of Chemistry University of Zurich Winterthurerstr. 190 8057 Zurich Switzerland