1. Department of Biomaterials; Radboud University Medical Center; 6525 EX Nijmegen The Netherlands
2. Chemistry, Materials and Chemical Engineering Department “G. Natta,”; Politecnico di Milano; 20133 Milano Italy
3. Institute of Organic and Macromolecular Chemistry; Heinrich-Heine-University Düsseldorf; 40225 Düsseldorf Germany
4. Department of Biomaterials; Max Planck Institute for Colloids and Interfaces; D-14424 Potsdam Germany
5. Institute of Biomaterials; Department of Materials Science and Engineering; University of Erlangen-Nuremberg; 91058 Erlangen Germany