1. Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
2. Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 171 65, Sweden
3. Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
4. Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London W12 0NN, United Kingdom