1. Department of Orthodontics, University of Groningen and University Medical Center Groningen, W. J. Kolff Institute of Biomedical Engineering and Materials Science, Groningen, The Netherlands
2. Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, W. J. Kolff Institute of Biomedical Engineering and Materials Science, Groningen, The Netherlands
3. Department of Biomedical Engineering, The College of New Jersey, Ewing, NJ, USA
4. Willem Kolff Foundation (Kampen, NL), Zwolle, The Netherlands
5. Departments of Biomedical Engineering, and of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah, USA