1. Laboratory of Polymer Chemistry, University of Helsinki, Post Office Box 55, Helsinki, FIN-00014, Finland, Institute of Macromolecular Compounds, Bolshoi pr.31, 199004 St. Petersburg, Russia, Institute of Biotechnology and Department of Biological and Environmental Sciences, University of Helsinki, Post Office Box 65, Helsinki, FIN-00014, Finland, and Institute of Materials Chemistry, Tampere University of Technology, Post Office Box 541, Tampere, FIN-33101, Finland