1. Polymer Materials Research Group, Department of Organic Chemistry, Institute Biomedical Technology (IBITECH), University of Gent, Krijgslaan 281 S4bis, B-9000 Gent, Belgium, Laboratory of Biophysics and Surface Analysis, Department of Pharmaceutical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., and Department of Chemistry, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Wilrijk, Belgium