1. Department of Life Technologies, University of Turku, FIN-20014 Turku, Finland
2. Department of Pharmaceutical Sciences, College of Pharmacy, Ferris State University, Big Rapids, Michigan 49307, United States
3. Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
4. Department of Biotechnology and Nanomedicine, SINTEF AS, P.O. Box 4760 Torgarden, NO-7465 Trondheim, Norway