1. Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK.
2. Center for Cell Engineering, Institute of Molecular Cell and Systems Biology, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK.
3. Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 First Drive, Atlanta, GA 30332, USA.