1. Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King’s College London, St. Thomas’ Hospital, London SE1 7EH, U.K.
2. Institute of Pharmaceutical Sciences, School of Cancer & Pharmaceutical Sciences, King’s College London, Franklin Wilkins Building, London SE1 9NH, U.K.
3. Electron Microscopy Centre, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, Flowers Building, London SW7 2AZ, U.K.