1. Bionics Institute, East Melbourne, Victoria 3002, Australia
2. Department of Materials, Department of Bioengineering, and the Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
3. ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
4. Melbourne Advanced Microscopy Facility and Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia