1. Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
2. Department of Biomaterials, Max Planck Inst. for Colloids and Interfaces, Potsdam, Germany
3. Department of Bioengineering and Therapeutic Sciences, University of California – San Francisco, San Francisco, CA, USA
4. Department of Orthopaedic Surgery, Columbia University, New York, NY, USA
5. Experimental Division, European Synchrotron Radiation Facility, Grenoble, France