1. Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, U.K., Cancer Research U.K., Department of Medical Oncology, University of Glasgow, Garscube Estate, Glasgow G61 1BD, U.K., NanoAnalytical Laboratories, San Francisco, California 94118, Electron Microscopy Unit, School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, U.K., GlaxoSmithKline, New Frontiers Science Park (South), Third Avenue, Harlow, Essex, CM19 5AW, U.K.