1. Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
2. Department of Material Chemistry, Asahikawa National College of Technology, Asahikawa 071-8142, Japan
3. Division of Biotechnology and Macromolecular Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan