1. Institute of Biomaterials Department of Materials Science and Engineering; University of Erlangen-Nuremberg; 91058 Erlangen Germany
2. Department of Medicine and Pathology; University of Parma; 12-I 43126 Parma Italy
3. Institute of Polymeric Materials; Department of Materials Science and Engineering; University of Erlangen-Nuremberg; 91058 Erlangen Germany
4. Ibt - Immunological and Biochemical Testsystems GmbH Wiesenstr. 17; 88521 Binzwangen Germany
5. Department of Civil and Industrial Engineering; Largo Lucio Lazzarino; 56126 Pisa Italy