1. Division of Pharmaceutical Chemistry and Technology; Faculty of Pharmacy; University of Helsinki; FI-00014 Helsinki Finland
2. Laboratory of Industrial Physics; Department of Physics; University of Turku; FI-20014 Turku Finland
3. School of Engineering and Applied Sciences; Harvard University; Cambridge MA 02138 USA
4. Laboratory of Polymer Chemistry; Department of Chemistry; University of Helsinki; FI-00014 Helsinki Finland