1. Department of Materials Science and Engineering; Institute of Biomaterials; University of Erlangen-Nuremberg; 91058 Erlangen Germany
2. Johan Gadolin Process Chemistry Centre; Åbo Akademi University; 20500 Turku Finland
3. Faculty of Technology and Metallurgy; University of Belgrade; 11001 Belgrade Serbia
4. Department of Materials; Imperial College London; South Kensington Campus London SW7 2AZ UK