title: Development of a temperature sensitive drug release system for polymeric implant devices.
abstract: A low density polyethylene (LDPE) model surface was coated with poly(amino-p-xylylene) (amino-ppx) via chemical vapour deposition (CVD) polymerization. The functional surface was used to immobilize a polymeric drug release system consisting of poly(N-isopropylacrylamide) (NIPAAm)-co-poly(acrylic acid) (AAc). The coupled drug release system was used to incorporate the thrombin inhibitor r-hirudin. For the investigation of the concentration of incorporated r-hirudin and the release profile over a given period of time r-hirudin was labelled with 123I as well as fluorescein isothiocyanate (FITC). Using an incubation solution concentration of 0.2% at pH 5 and an ionic strength of 0.7 M a maximum concentration of 2.21 (+/- 0.11) nmol/cm2 of r-hirudin was detected. FITC-r-hirudin was almost quantitatively (2.08 +/- 10 nmol/cm2; 94%) released from the surface coating within a period of 14 days.
authors.affiliation: Department of Textile Chemistry and Macromolecular Chemistry, RWTH Aachen, Veltmanplatz 8, 52062 Aachen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Roos
authors.forename: Doris
authors.initials: D
authors.lastname: Klee
authors.forename: Karl
authors.initials: K
authors.lastname: Schuermann
authors.forename: Hartwig
authors.initials: H
authors.lastname: Höcker
mesh_terms: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004343:Drug Implants; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006629:Hirudins / Q000737:chemistry / Q000493:pharmacokinetics* / Q000648:ultrastructure; D007457:Iodine Radioisotopes; D018625:Microscopy, Atomic Force; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004343:Drug Implants; D005456:Fluorescent Dyes; D006629:Hirudins; D007457:Iodine Radioisotopes; D016650:Fluorescein-5-isothiocyanate