1. a National ESCA and Surface Analysis Center for Biomedical Problems, Department of Chemical Engineering, BF-10, University of Washington, Seattle, WA 98195, USA
2. b National ESCA and Surface Analysis Center for Biomedical Problems, Department of Chemical Engineering, BF-10, University of Washington, Seattle, WA 98195, USA
3. c Center for Controlled Chemical Delivery, 421 Wakara Way, 318, Salt Lake City, UT 84108, USA
4. d Center for Controlled Chemical Delivery, 421 Wakara Way, 318, Salt Lake City, UT 84108, USA
5. e Institute of Biomedical Engineering and International Center for Biomaterials Science, Tokyo Women's Medical College, 8 Kawada, Shinjuku, Tokyo 162, Japan
6. f Institute of Biomedical Engineering and International Center for Biomaterials Science, Tokyo Women's Medical College, 8 Kawada, Shinjuku, Tokyo 162, Japan
7. g ICI plc, Wilton Materials Research Centre, PO Box 90, Wilton, Middlesbrough, Cleveland TS6 8JE, UK
8. h Department of Polymer Chemistry, Tokyo Institute of Technology, Ohokayama, Meguro-ku, Tokyo 152, Japan