- molecular logic-gate circuits and automata (such as MAYA-II, which plays tic-tac-toe interactively with a human opponent)
- visual interfaces for molecular computation (eg dot-matrix displays)
- smart diagnostic devices, including computational arrays for viral lineage attribution
- therapeutic molecular devices (such as enzyme-based cocaine detoxification)
- materials engineering (such as nucleic acid form and function for synthetic building materials)
Dr Macdonald’s research is focused on the application of molecular engineering as a tool to solve mathematical and biological problems. Molecular engineering involves the construction of new molecules and molecular networks that would otherwise not exist in nature.
For example, Dr Macdonald previously developed a molecular automaton able to play tic-tac-toe interactively with a human opponent, constructed from a network of more than one hundred different DNA molecules.
This research represented the first DNA-based medium-scale integrated circuit [NANO LETT 2006, 6:2598 -2603], and has been featured in popular science magazines such as the New Scientist [NEW SCI 2006, 191:24-25] and Scientific American [SCI AM 2008, Nov.:84–91].
Dr Macdonald’s current research projects in molecular engineering are a natural extension of her background in molecular computation, enzymology, virology, and molecular biology.
Dr Macdonald’s virology and molecular biology experience was obtained during doctoral studies at the University of Queensland (1998-2003) and post-doctoral studies at Columbia University (2002-2004).
Highlights from this research includes a diagnostic assay for detection of West Nile virus [J VIROL 2006, 22:13924-33] and a molecular epidemiological study of Edge Hill virus (originally isolated in Cairns, Qld.) [EVOL BIOINFORM 2010, 6:91–96].
Dr Macdonald’s molecular computation and enzymology experience was obtained in the Division of Experimental Therapeutics at Columbia University (2004-2012).
Apart from developing molecular automata, highlights from this research was the pharmacological development an enzyme with improved thermal stability for the treatment of cocaine-intoxication [PEDS 2010, 23: 537-547; MOL PHARMACOL 2009, 75:318-23], and the development of a nomenclature for in-silico high-throughput screening of nucleic acid folding [2ND ACM CONF PROCEEDINGS 2011, p404-408].
The use of molecules as engineering building blocks rather than biological observations is transformative, and when applied cross-disciplinarily can provide unique solutions to traditionally difficult problems.
At USC, Dr Macdonald’s research intentionally provides a broad scope for researchers and students to pursue interesting and novel ideas that will continue to define this emerging field of molecular engineering.
Many of Dr Joanne Macdonald's publications are available from the USC Research Bank.