1. Department of Biomedical Engineering; The Chinese University of Hong Kong; Hong Kong 999077 China
2. Department of Materials Science and Engineering; Northwestern University; Evanston IL 60208 USA
3. International Institute for Nanotechnology; Evanston IL 60208 USA
4. NUANCE Center; Northwestern University; Evanston IL 60208 USA
5. Department of Orthopaedics & Traumatology; Faculty of Medicine; The Chinese University of Hong Kong; Prince of Wales Hospital; Hong Kong 999077 China
6. Shenzhen Research Institute; The Chinese University of Hong Kong; Shenzhen 518172 China