Centre for Advanced Macromolecular Design (CAMD), The University of New South Wales (UNSW), Sydney 2052, NSW, Australia, Children’s Cancer Institute Australia for Medical Research, Sydney 2031, NSW, Australia, and School of Biotechnology and Biomolecular Sciences (BABS), The University of New South Wales (UNSW), Sydney 2052, NSW, Australia (At 2008-06-20)