1. Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, 91058 Erlangen, Germany
2. Department of Civil and Industrial Engineering, University of Pisa, Largo Lucio Lazzarino, 56126 Pisa, Italy
3. Inspiralia, Materials Laboratory, C/Faraday 7, Lab 3.02, Campus de Cantoblanco, Madrid 28049, Spain