1. Center for Nanotechnology in Drug Delivery; Division of Molecular Pharmaceutics; Eshelman School of Pharmacy; University of North Carolina at Chapel Hill; NC 27599 USA
2. Department Chemie; Technische Universität Dresden; Mommsenstr. 4 01069 Dresden Germany
3. Functional Polymer Materials; Chair for Chemical Technology of Materials Synthesis; Universität Würzburg; 97070 Würzburg Germany
4. Laboratory for Chemical Design of Bionanomaterials; Faculty of Chemistry; M.V. Lomonosov Moscow State University; Moscow 119899 Russia